1 Scope

1.1 Boundary of Work

NOTE This standard governs the chiller as a unit of supply: the compressor and its drive, the evaporator, the condenser where one is integral to the package, the refrigerant circuit and its charge, the lubrication and oil management system, the pressure relief devices, the unit controller, the integral power and control enclosure, the factory-mounted starter or drive, and the accessories the chiller manufacturer mounts and wires before shipment. (1.1.1)

NOTE The boundary is the chilled water connections, the condenser water connections where the machine is water-cooled, the relief device outlet, and the power and control terminations in the unit enclosure. Everything on the far side of those five interfaces belongs to another standard. (1.1.2)

NOTE The standard also reaches into four execution activities that determine whether the machine performs as rated — setting and anchoring, the water-side connection arrangement, the relief vent routing, and manufacturer startup. A chiller that meets its certified rating on a factory test stand and disappoints in the field almost always does so because of a system condition delivered to it rather than a defect inside it. (1.1.3)

NOTE Work outside this boundary is governed by the standards named below, and this standard defers to them rather than restating their requirements: (1.1.4)

Chilled water and condenser water piping, valves, strainers, flexible connectors, and pipe supports beyond the chiller connections — Hydronic PipingHydronic PipingResolves to the current edition.sync/hydronic-piping
Chilled water and condenser water circulating pumps — HVAC PumpsHVAC PumpsResolves to the current edition.sync/hvac-pumps
The cooling tower, fluid cooler, or other heat rejection device serving a water-cooled machine — Cooling TowersCooling TowersResolves to the current edition.sync/cooling-towers
Chemical treatment, filtration, and biological control of both the closed chilled water loop and the open condenser water loop — HVAC Water TreatmentHVAC Water TreatmentResolves to the current edition.sync/hvac-water-treatment
Cleaning and flushing of the loops before the chiller is placed in service — Hydronic Cleaning And FlushingHydronic System Cleaning and FlushingResolves to the current edition.sync/hydronic-cleaning-and-flushing
Plant sequencing, staging, alarming, and trending resident in the control system — Building Automation SystemBuilding Automation SystemResolves to the current edition.sync/building-automation-system
System flow balancing and verification of terminal flow rates — Testing Adjusting And BalancingTesting, Adjusting, and Balancing for HVACResolves to the current edition.sync/testing-adjusting-and-balancing
Field insulation of connected piping and of any surface the chiller manufacturer does not insulate — Mechanical InsulationMechanical InsulationResolves to the current edition.sync/mechanical-insulation
Housekeeping pads and equipment foundations — Concrete PadsConcrete Equipment PadsResolves to the current edition.sync/concrete-pads
Equipment grounding and bonding — Grounding And BondingGrounding and Bonding for Electrical SystemsResolves to the current edition.sync/grounding-and-bonding
Equipment nameplates, pipe marking, and arc-flash labeling — Mechanical IdentificationMechanical IdentificationResolves to the current edition.sync/mechanical-identification

NOTE A chiller is a single machine that behaves like a system component. Its capacity, its efficiency, and its service life depend on the condenser water temperature delivered to it, the chilled water flow held through it, the electrical supply feeding it, and the control logic commanding it, none of which the machine controls. That is why this standard spends as much text on rating conditions and interfaces as on the hardware inside the shells. (1.1.5)

1.2 Terms Used in This Standard

NOTE The following terms carry the meanings given in ANSI/AHRI 550/590 and ANSI/ASHRAE 15 and 34 throughout this standard: (1.2.1)

Ton of refrigeration — 12,000 Btu/h of net cooling capacity measured at the evaporator water connections
Standard rating conditions — the temperatures, flow rates, and fouling allowances at which ANSI/AHRI 550/590 requires published ratings to be determined
Lift — the difference between condensing and evaporating saturation temperature the compressor must overcome, which for a given machine is set by the leaving chilled water temperature and the entering condenser fluid temperature
Approach — the difference between the refrigerant saturation temperature in a shell and the water temperature leaving that shell, which rises as the tubes foul
Integrated part-load value, IPLV — the single-number part-load figure of merit ANSI/AHRI 550/590 computes by weighting performance at 100, 75, 50, and 25 percent of full capacity at the standard rating conditions
Non-standard part-load value, NPLV — the same weighted figure computed at rating conditions other than the standard ones, which is what applies whenever a project schedules its own temperatures
Refrigerant concentration limit, RCL — the concentration in a volume of occupied space above which ANSI/ASHRAE 34 does not permit a refrigerant, and the quantity ANSI/ASHRAE 15 uses to decide whether a refrigerating machinery room is required
Low-pressure refrigerant — a refrigerant whose saturation pressure at ordinary operating temperature is below atmospheric pressure, so that the machine runs partly in vacuum and admits air and moisture through any leak rather than losing charge
Surge — the flow reversal a centrifugal compressor undergoes when the lift demanded exceeds what the impeller can develop at the flow available

2 Referenced Standards

2.1 Equipment, materials, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited.

2.2 Where referenced standards conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.

2.3 Where the project jurisdiction has adopted an energy code more stringent than ANSI/ASHRAE/IES 90.1, the adopted local requirement shall govern.

Standard	Title
ANSI/AHRI 550/590 (I-P)	Performance Rating of Water-Chilling and Heat Pump Water-Heating Packages Using the Vapor Compression Cycle
ANSI/AHRI 551/591 (SI)	Performance Rating of Water-Chilling and Heat Pump Water-Heating Packages Using the Vapor Compression Cycle, SI Units
ANSI/AHRI 370	Sound Performance Rating of Large Air-Cooled Outdoor Refrigerating and Air-Conditioning Equipment
ANSI/AHRI 575	Method of Measuring Machinery Sound Within an Equipment Space
AHRI Guideline E	Fouling Factors in Air-Conditioning and Refrigeration Equipment
ANSI/ASHRAE 15	Safety Standard for Refrigeration Systems
ANSI/ASHRAE 34	Designation and Safety Classification of Refrigerants
ANSI/ASHRAE/IES 90.1	Energy Standard for Sites and Buildings Except Low-Rise Residential Buildings
ANSI/ASHRAE 188	Legionellosis: Risk Management for Building Water Systems
ASME Boiler and Pressure Vessel Code, Section VIII, Division 1	Rules for Construction of Pressure Vessels
ASME B31.5	Refrigeration Piping and Heat Transfer Components
ASME B16.1	Gray Iron Pipe Flanges and Flanged Fittings
ASME B16.5	Pipe Flanges and Flanged Fittings, NPS 1/2 Through NPS 24
UL 60335-2-40	Household and Similar Electrical Appliances, Particular Requirements for Electrical Heat Pumps, Air-Conditioners, and Dehumidifiers
UL 1995	Heating and Cooling Equipment
NFPA 70	National Electrical Code, Articles 430 and 440
IEEE 519	Harmonic Control in Electric Power Systems
NEMA MG 1	Motors and Generators
NEMA 250	Enclosures for Electrical Equipment, 1000 Volts Maximum
ASCE/SEI 7	Minimum Design Loads and Associated Criteria for Buildings and Other Structures
IBC	International Building Code
40 CFR Part 82	Protection of Stratospheric Ozone, Refrigerant Management
40 CFR Part 84	Phasedown of Hydrofluorocarbons Under the American Innovation and Manufacturing Act
29 CFR 1910.147	The Control of Hazardous Energy, Lockout and Tagout

3 Submittals

3.1 Action Submittals

3.1.1 The Contractor shall submit the following for review and approval before any chiller is released for fabrication:

Product data for each chiller tag, identifying the model designation, compressor type and quantity, refrigerant, operating and shipping weight, overall dimensions, and every factory-mounted accessory furnished
Certified performance data at the scheduled design conditions, stating net cooling capacity, power input, evaporator and condenser flow rates, entering and leaving fluid temperatures, fouling allowances, and water-side pressure drops
Part-load performance data at 100, 75, 50, and 25 percent of design capacity at the scheduled conditions, with the resulting integrated or non-standard part-load value and the weighting applied
Statement of the certification program under which the ratings were determined, or a statement of why the machine falls outside every applicable program
Minimum and maximum evaporator and condenser flow rates, the minimum entering condenser fluid temperature, and the maximum permitted rate of change of evaporator flow
Electrical data including full-load amperes, locked-rotor or inrush amperes, minimum circuit ampacity, maximum overcurrent protective device size, and short-circuit current rating
Starter or drive data, including the harmonic current spectrum at the design point where a variable-speed drive is furnished
Sound power data by octave band at full load and at the part-load points, with the rating standard under which it was measured
Refrigerant designation, safety group classification, global warming potential, and total operating charge for each independent circuit
Pressure relief device data including set pressure, relieving capacity, and the discharge pipe size and equivalent length the relief calculation permits
Refrigerant concentration calculation for the space in which the chiller is installed, prepared against ANSI/ASHRAE 15
Pressure vessel data including design pressure, code of construction, and code stamp
Unit controller data including the point list, the protective shutdown list, and the communication interface offered
Dimensional and rigging drawings showing the operating footprint, lifting points, center of gravity, shipping split arrangement, and the tube removal clearance the machine requires
Vibration isolation product data including rated load, static deflection, and natural frequency at the operating load
Seismic restraint calculations and attachment details, stamped by a professional engineer registered in the project jurisdiction
Coordination drawings showing the chiller footprint, water and electrical connection locations, relief vent routing, and maintenance access

Action Submittals Requiredcheckbox

☑ Chiller product data by tag

☑ Certified performance data at the design conditions

☑ Part-load performance data and the part-load value

☑ Rating certification program statement

☑ Flow limits and minimum entering condenser fluid temperature

☑ Electrical data including short-circuit current rating

☐ Starter or drive data with harmonic current spectrum

☑ Sound power data by octave band

☑ Refrigerant designation, safety group, and operating charge

☑ Pressure relief device data and relief pipe sizing limits

☑ Refrigerant concentration calculation against ANSI/ASHRAE 15

☑ Pressure vessel data and code stamp

☑ Unit controller point list and protective shutdown list

☑ Dimensional and rigging drawings with tube removal clearance

☐ Vibration isolation product data

☐ Seismic restraint calculations and details

☑ Coordination drawings with maintenance access

3.1.2 Fabrication and shipment shall not proceed until the action submittals for that chiller tag have been returned marked no exceptions taken or make corrections as noted.

NOTE The single most consequential page in the submittal is the certified performance data at the scheduled conditions rather than at the standard rating conditions. A machine that is comfortably efficient at 85°F entering condenser water can be several percent short at 78°F if the condenser was selected for the standard point, and the difference never appears in a catalog rating. (3.1.3)

NOTE The refrigerant concentration calculation is the item most often omitted and the one that most often changes the design. It is what determines whether a refrigerating machinery room, its ventilation, and its detection are required, and discovering that after the room is built is expensive in a way no other submittal item is. (3.1.4)

3.2 Closeout Submittals

3.2.1 The Contractor shall submit the following before the chillers are accepted:

Operation and maintenance manuals for each chiller model furnished, including the wiring diagrams as built and the control sequence as programmed
As-built nameplate record for each installed chiller, including serial number, refrigerant designation, charge quantity, and electrical ratings
Certified factory test report for each chiller tag for which factory testing was required
Manufacturer startup report signed by the technician who performed it, recording the readings taken and the setpoints left in the controller
Field functional performance test report correlating measured capacity and power input to the certified performance data
Refrigerant charge record stating the quantity charged, the date, and the technician certification number
Water treatment acceptance record for both loops the chiller serves, obtained from the party responsible under HVAC Water TreatmentHVAC Water TreatmentResolves to the current edition.sync/hvac-water-treatment
Vibration isolation and seismic restraint installation certification
Owner training record identifying the attendees, the duration, and the topics covered
Warranty documentation correlating each serial number to its installation date and warranty expiration date
Spare parts inventory identifying each item by chiller tag and manufacturer part number

Closeout Submittals Requiredcheckbox

☑ Operation and maintenance manuals with as-built wiring and sequence

☑ As-built nameplate record with refrigerant charge quantity

☐ Certified factory test report

☑ Signed manufacturer startup report

☑ Field functional performance test report

☑ Refrigerant charge record with technician certification

☐ Water treatment acceptance record for both loops

☐ Vibration isolation and seismic restraint certification

☑ Owner training record

☑ Warranty documentation by serial number

☑ Spare parts inventory by chiller tag and part number

3.2.2 The refrigerant charge quantity shall be recorded from the machine as charged rather than copied from the catalog, and shall be marked on the unit nameplate.

NOTE The recorded charge is what every later leak-rate calculation divides by, and 40 CFR Part 82 leak thresholds are expressed as a percentage of the full charge. A machine whose recorded charge is a catalog number rather than the quantity actually in it produces a leak rate that is wrong by whatever the difference is, in the direction that delays a repair. (3.2.3)

3.3 Informational Submittals

3.3.1 The Contractor shall submit the following for information:

Manufacturer's published installation, operation, and maintenance instructions, delivered before the chiller is set
Field quality control procedure the manufacturer requires before it will perform startup
Rigging plan identifying the lift path, the rigging points, and the shipping split arrangement
Certification of the technicians who will handle refrigerant, issued under 40 CFR Part 82
Recommended preventive maintenance schedule with intervals, and the manufacturer's published water quality limits for both loops

Informational Submittals Requiredcheckbox

☑ Installation, operation, and maintenance instructions

☑ Manufacturer pre-startup checklist

☐ Rigging plan with lift path and shipping splits

☑ Refrigerant technician certification

☑ Preventive maintenance schedule and published water quality limits

NOTE The published water quality limits matter beyond maintenance planning, because the warranty exclusions in this standard are conditioned on the manufacturer having stated those limits where the Owner could see them. (3.3.2)

4 Quality Assurance

4.1 Manufacturer Qualifications

4.1.1 The chiller manufacturer shall have continuously designed and produced liquid chillers of the compressor type and capacity range furnished for not less than the period indicated in the datasheet.

Minimum Manufacturer Experiencerange

years

3510152025

4.1.2 The manufacturer shall maintain a documented quality management system covering pressure vessel fabrication, refrigerant circuit cleanliness, assembly, and production testing.

4.1.3 The manufacturer shall maintain a factory-trained service organization capable of reaching the project site within the response time indicated in the datasheet.

Maximum Service Response Timerange

hours

24812244872

4.1.4 The manufacturer shall commit in writing that replacement parts for the model furnished will remain available for not less than the period indicated in the datasheet, measured from the date of manufacture.

Minimum Replacement Parts Availability Periodrange

years

51015202530

NOTE A chiller is the piece of equipment in a building most likely to be repaired rather than replaced at the end of a component's life, because the shells outlast everything attached to them. A twenty-year parts commitment is therefore worth more on a chiller than on almost any other machine in the plant. (4.1.5)

4.2 Certification of Rated Performance

4.2.1 Rated performance shall be certified under the programs indicated in the datasheet.

Performance Certification Requiredcheckbox

☑ AHRI certification for water-cooled water-chilling packages

☑ AHRI certification for air-cooled water-chilling packages

☐ Sound performance certification under ANSI/AHRI 370

☐ Independent third-party witnessed rating verification

4.2.2 Where the machine falls outside the scope of every applicable certification program, the submittal shall identify the scope limit that places it outside and shall state the basis on which its ratings were determined.

4.2.3 Ratings shall be determined and reported in accordance with ANSI/AHRI 550/590 or ANSI/AHRI 551/591.

4.2.4 Where the scheduled conditions differ from the standard rating conditions, the part-load figure reported shall be identified as a non-standard part-load value and the conditions used shall be stated with it.

NOTE A certification program does not certify the machine on the drawings. It certifies that the manufacturer's published rating method produces results within tolerance when a randomly selected production unit is tested, which is a statement about the catalog rather than about the tag. That is still worth a great deal, because it makes the selection software the design was based on accountable to a third party. (4.2.5)

NOTE Very large centrifugal machines and machines built for unusual duty routinely fall outside the certification scope, which is a fact about program boundaries rather than a defect in the machine. What matters is that the submittal say so plainly instead of implying a certification the machine does not carry. (4.2.6)

4.3 Pressure Vessel Construction and Electrical Listing

4.3.1 Refrigerant-side pressure vessels shall be constructed to the code indicated in the datasheet.

Pressure Vessel Code of Constructionradio

● ASME Section VIII Division 1, code stamped and registered

○ ASME Section VIII Division 1, constructed to the code without a stamp

○ Constructed to the pressure requirements of ANSI/ASHRAE 15 below the ASME size threshold

4.3.2 The complete chiller package shall be listed by a nationally recognized testing laboratory under the standard indicated in the datasheet.

Electrical Safety Listing Basisselect

UL 60335-2-40

UL 1995

UL 60335-2-40 with the flammable refrigerant provisions applied

4.3.3 Refrigerant piping and joints internal to the package shall conform to ASME B31.5.

NOTE Vessels below the size threshold of ASME Section VIII are outside the code's own scope rather than exempted from it by choice, which is why the third option exists at all. Small brazed-plate and compact shell machines commonly fall there, and requiring a stamp they cannot receive delays procurement without improving anything. (4.3.4)

NOTE The listing standard is the item most often left to the Authority Having Jurisdiction, because UL 60335-2-40 and the older UL 1995 are both accepted in most of the country while the flammable-refrigerant provisions are what an A2L machine actually needs. Naming it in the datasheet rather than leaving it blank avoids a listing argument at final inspection. (4.3.5)

4.4 Single-Source Responsibility for the Package

4.4.1 The compressor, evaporator, condenser where integral, refrigerant circuit, unit controller, and integral power equipment shall be furnished as one factory-assembled package by or through one chiller manufacturer.

4.4.2 The chiller manufacturer shall be responsible for the thermodynamic performance of the package, the compatibility of its components, and the coordination of its electrical and control interfaces.

4.4.3 Where a starter, drive, or condenser is furnished separately from the chiller under the Contract Documents, the responsibility for the interface and for the resulting performance shall be stated in writing before that equipment is released for fabrication.

NOTE Splitting a chiller package is a real procurement pattern, usually driven by an owner's standardization program for drives or by a remote condenser location. It works when the split is declared in advance and the performance obligation is redrawn to match. What causes disputes is a split discovered at startup, when a capacity shortfall has two suppliers each pointing at the other. (4.4.4)

4.5 Manufacturer Startup Service

4.5.1 The Contractor shall engage the chiller manufacturer's own service organization to perform the initial startup of each chiller at or above the capacity indicated in the datasheet.

Cooling Capacity Threshold for Manufacturer Startup Servicerange

tons

2050100200300500

NOTE A setpoint of 0 tons requires manufacturer startup on every chiller on the project. (4.5.2)

4.5.3 The startup technician shall hold the refrigerant handling certification required under 40 CFR Part 82 for the equipment type.

4.5.4 The chiller shall not be energized for operation before the manufacturer's pre-startup checklist has been completed and signed.

NOTE Manufacturer startup buys two things a competent contractor startup does not. The technician has the factory service tool that reads the controller's internal state rather than only its displayed points, and the visit itself is usually the condition on which the warranty depends. Both are worth more on a machine with a proprietary controller than on one with an open interface. (4.5.5)

4.6 Preinstallation Conference

4.6.1 A preinstallation conference shall be held before the first chiller is rigged into place, attended by the mechanical contractor, the chiller manufacturer's representative, the electrical contractor, the controls contractor, the balancing agency, the commissioning authority where one is engaged, and the Owner's representative.

4.6.2 The conference agenda shall cover the rigging path and shipping split arrangement, the housekeeping pad and anchorage, the tube removal clearance as built against the approved coordination drawings, the relief vent routing, the electrical termination arrangement, the loop cleaning and flushing status required before startup, the control interface points, and the sequence in which the loops will be filled, treated, and released.

4.6.3 Minutes of the conference shall be distributed to all attendees and to the Engineer of Record within five business days.

NOTE The item on that agenda most often skipped and most often regretted is the loop cleaning status. A chiller started on water that still carries construction debris fouls its evaporator tubes on the first day, and the resulting approach never returns to the value the machine was rated at without a mechanical cleaning. (4.6.4)

5 Service Conditions and Site Data

5.1 Installation Environment

5.1.1 Chillers shall be installed in the locations and orientations chiller locations as indicated on the mechanical plans.

5.1.2 The chiller shall be constructed for the exposure indicated in the datasheet.

Chiller Exposure Constructionradio

○ Indoor construction

○ Outdoor construction with weather-resistant enclosures over electrical equipment

○ Outdoor construction with a full weatherproof housing over the machine

5.1.3 Where the chiller is installed outdoors, the control and power enclosures shall be rated not less than NEMA 250 Type 3R and shall be furnished with condensation control appropriate to the minimum ambient temperature indicated in the datasheet.

5.1.4 The exterior finish system shall be as indicated in the datasheet.

Exterior Finish Systemselect

Baked powder coat over a phosphatized substrate

Air-dry enamel

Two-coat epoxy system

High-build coastal coating system

Manufacturer's standard (by default)

NOTE An outdoor chiller and an indoor chiller of the same capacity are not the same machine with a different paint job. The outdoor unit carries sealed enclosures, heaters in the control panel, a low-ambient operating range, and a coil arrangement that has to survive weather, and converting one to the other after selection is rarely possible. (5.1.5)

NOTE Salt-laden air is the exposure that separates the coating systems. Within roughly a mile of open saltwater, the chloride deposition rate on an outdoor coil and on a painted frame is high enough that an ordinary powder coat and a bare aluminum fin both lose material measurably within a few years, which is the condition that justifies the coastal system. (5.1.6)

5.2 Machinery Space Conditions

5.2.1 The chiller shall operate continuously across the ambient temperature range indicated in the datasheet at the space in which it is installed.

Maximum Ambient Dry-Bulb Temperature at the Chillerrange

°F

809095100105110115120130

Per drawings — design conditions as indicated on the mechanical drawings (deferred by default)

Minimum Ambient Dry-Bulb Temperature at the Chillerrange

°F

-40-20-10102032405060

Per drawings — design conditions as indicated on the mechanical drawings (deferred by default)

Maximum Relative Humidity at the Chillerrange

%

30405060708090100

5.2.2 Where the datasheet indicates no minimum ambient temperature, the chiller shall be capable of operation down to the manufacturer's published minimum ambient for the model furnished, and that value shall be stated in the submittal.

5.2.3 Where the chiller must operate below the manufacturer's standard minimum ambient, low-ambient operating provisions shall be furnished and shall be identified in the submittal.

NOTE Minimum ambient temperature is a control problem rather than a cold-weather durability problem. An air-cooled machine in cold air condenses at a pressure too low to drive refrigerant through the expansion device, so it either needs head pressure control that holds condensing pressure up or it shuts down. A machine that must make chilled water in January for a data center or a process load is a different selection from one that runs only in cooling season. (5.2.4)

NOTE Relative humidity governs the insulation on the cold surfaces rather than the machine. The insulation has to keep the outer surface above the dew point of the surrounding air, and a mechanical room that runs humid because it is unconditioned and below grade needs materially more insulation than one inside the building envelope. (5.2.5)

5.3 Site Elevation

5.3.1 The site elevation shall be as indicated in the datasheet, and rated capacity and power input shall be corrected for that elevation.

Site Elevationrange

ft

1000200033005000660080001000012000

Per drawings — site elevation as indicated on the contract documents (deferred by default)

5.3.2 Where the site elevation exceeds 3,300 ft, the manufacturer shall confirm the rating of the compressor motor, of any condenser fan motor, and of the air-cooled condenser at that elevation and at the maximum ambient temperature indicated.

NOTE Thin air acts on an air-cooled chiller twice. The condenser moves the same volume of air but less mass, so heat rejection falls and condensing temperature rises; and the same convective loss that cools an open motor weakens, so the motor derates. Neither correction appears in a sea-level catalog rating, and together they can cost a Denver installation several percent of capacity at the design point. (5.3.3)

5.4 Refrigerating Machinery Room

5.4.1 The refrigerating machinery room requirement for the space in which the chiller is installed shall be as indicated in the datasheet.

Refrigerating Machinery Roomradio

○ Required, machinery room provided under ANSI/ASHRAE 15

○ Not required, refrigerant quantity below the concentration limit for the space

Per drawings — machinery room designation as indicated on the mechanical drawings (deferred by default)

5.4.2 The Contractor shall submit a refrigerant concentration calculation for the space in which the chiller is installed, comparing the operating charge of the largest single circuit to the refrigerant concentration limit of ANSI/ASHRAE 34 for the volume of that space.

5.4.3 Where the calculation shows the concentration limit exceeded, the Contractor shall notify the Engineer of Record before the chiller is released for fabrication.

5.4.4 Where a refrigerating machinery room is provided, refrigerant detection, alarm, and emergency ventilation shall conform to ANSI/ASHRAE 15 and shall be interlocked with the chiller as required by that standard.

NOTE Whether a machinery room is required is decided by arithmetic rather than by preference: the charge in one circuit, divided by the volume of the smallest space it could leak into, against a published concentration limit for that refrigerant. Two identical machines with different refrigerants can land on opposite sides of that line, and so can the same machine in two rooms. (5.4.5)

NOTE The calculation uses the volume of the space the refrigerant can actually reach, which is usually smaller than the room. A machine on a mezzanine with an open guardrail and a machine in a sealed vault of the same nominal cubic footage do not get the same answer. (5.4.6)

5.5 Circulated Fluids

5.5.1 The chilled water loop fluid shall be as indicated in the datasheet, and all wetted components shall be compatible with that fluid at the operating temperature and treatment chemistry.

Chilled Water Loop Fluidselect

Water

Propylene glycol and water solution

Ethylene glycol and water solution

Methanol and water solution

Deionized or demineralized water

Chilled Water Glycol Concentration by Volumerange

%

1020253035405060

Per drawings — fluid concentration as indicated on the mechanical schedules (deferred by default)

5.5.2 The condenser water loop fluid shall be as indicated in the datasheet.

Condenser Water Loop Fluidselect

Water

Propylene glycol and water solution

Ethylene glycol and water solution

Not applicable, the chiller rejects heat to air

Condenser Water Glycol Concentration by Volumerange

%

1020253035405060

Per drawings — fluid concentration as indicated on the mechanical schedules (deferred by default)

5.5.3 Where either loop carries a glycol solution, the certified performance data shall be corrected for the density, viscosity, specific heat, and thermal conductivity of that solution at the design temperatures.

5.5.4 Water quality in both loops shall be maintained within the manufacturer's published limits under HVAC Water TreatmentHVAC Water TreatmentResolves to the current edition.sync/hvac-water-treatment.

NOTE Glycol degrades chiller performance in a way that surprises designers who expect a freeze-protection penalty and nothing more. Specific heat falls, so a given ΔT carries less heat and the flow has to rise; viscosity rises, so the tube-side film coefficient falls and the water-side pressure drop climbs. A 30 percent propylene glycol solution can cost several percent of capacity and add half again to the evaporator pressure drop compared to water. (5.5.5)

NOTE The two glycols are not interchangeable on performance. Ethylene glycol has the better thermal properties at equal freeze protection and propylene glycol has the lower toxicity, which is why the choice is normally driven by whether the loop can reach potable water or a food process rather than by the heat transfer. (5.5.6)

6 Rated Capacity and Rating Conditions

6.1 Design Cooling Capacity

6.1.1 Each chiller shall be selected and certified to deliver the net cooling capacity indicated in the datasheet at the design conditions indicated in this section.

Design Net Cooling Capacityrange

tons

5102030507510015020030040050075010001250150020002500300040006000

Per drawings — mechanical equipment schedule (deferred by default)

6.1.2 The number of chillers and the plant arrangement shall be as indicated in the datasheet.

Chiller Plant Arrangementselect

Single chiller, no redundancy

Two chillers in parallel, each at half the plant capacity

Two chillers in parallel, each at full plant capacity

Three or more chillers in parallel, staged by load

Two chillers in series, series counterflow arrangement

Lead chiller with a smaller pony chiller for low load

Per drawings — mechanical equipment schedules and flow diagrams (deferred by default)

6.1.3 No capacity safety factor shall be added to the scheduled capacity by the Contractor or by the chiller supplier; where the selection requires margin, that margin shall be established by the Engineer of Record and reflected in the scheduled duty.

NOTE Chiller capacity is a scheduled quantity rather than a property of the standard, which is why it defers to the equipment schedule. What the standard can say is that the number on the schedule is the number, because margin added downstream of the design compounds: a designer's ten percent, a supplier's rounding up to the next machine size, and a redundant unit sized to the whole plant together produce a plant that never leaves its lowest stage. (6.1.4)

NOTE Series counterflow deserves its place in the list because it changes the thermodynamics rather than only the piping. Splitting the total lift between two machines lets the upstream chiller make warm chilled water at low lift and high efficiency while only the downstream machine works against the full lift, which is why the arrangement appears on large plants designed for a wide ΔT. (6.1.5)

6.2 Chilled Water Conditions

6.2.1 The evaporator shall be selected for the chilled water temperatures and flow indicated in the datasheet.

Design Leaving Chilled Water Temperaturerange

°F

2024283236384042444548505560

Per drawings — mechanical equipment schedule (deferred by default)

Design Entering Chilled Water Temperaturerange

°F

303642485254565860657080

Per drawings — mechanical equipment schedule (deferred by default)

Design Evaporator Flow Raterange

gpm

52050100200300500750100015002000300040006000900012000

Per drawings — mechanical equipment schedule (deferred by default)

Maximum Evaporator Water-Side Pressure Droprange

ft w.c.

51015202530405060

Per drawings — mechanical equipment schedule (deferred by default)

6.2.2 Leaving chilled water temperatures below 40°F shall be reviewed against the freeze protection of the fluid indicated in the datasheet, and the submittal shall state the refrigerant saturation temperature at the design point.

NOTE Every degree of leaving chilled water temperature is worth roughly one to two percent of compressor power, because it comes directly off the lift. Raising the loop from 42°F to 45°F is one of the cheapest efficiency measures available on an existing plant, and it is available only if the coils and the dehumidification load were designed to accept it. (6.2.3)

NOTE Water-side pressure drop is a real cost carried by the pumps for the life of the building, and it is the number most often traded away during value engineering. A chiller selected with a smaller shell and a higher pressure drop is cheaper on the day it is bought and more expensive every hour it runs, because the pump power the extra head demands is continuous while the capital difference is not. (6.2.4)

6.3 Heat Rejection Method

6.3.1 The method by which each chiller rejects heat shall be as indicated in the datasheet.

Heat Rejection Methodselect

Water-cooled, shell-and-tube condenser served by a condenser water loop

Water-cooled, plate condenser served by a condenser water loop

Air-cooled, integral finned condenser and fans

Evaporatively cooled, integral condenser with a recirculating water spray

Air-cooled, remote condenser furnished with the chiller

Condenserless, condensing surface furnished under a separate standard

6.3.2 Where the chiller is water-cooled, the condenser water loop shall be served by a heat rejection device conforming to Cooling TowersCooling TowersResolves to the current edition.sync/cooling-towers.

6.3.3 Where the chiller is furnished with a remote or separate condensing surface, the refrigerant line sizing, the maximum equivalent line length, the required charge addition, and the oil return provisions shall be stated by the chiller manufacturer and shall be shown on the coordination drawings.

NOTE This field carries no default because the choice is a plant-level design decision rather than an equipment preference, and both dominant answers are correct for the projects that choose them. A water-cooled machine reaches a lower condensing temperature than an air-cooled machine can on the same day, because a cooling tower approaches the wet-bulb and a dry coil approaches the dry-bulb, and the resulting efficiency difference at full load is large. (6.3.4)

NOTE What the water-cooled machine buys that efficiency with is a second water loop, a tower, condenser pumps, make-up water, blowdown, chemical treatment, and a Legionella management program under ANSI/ASHRAE 188. Where water is scarce or expensive, where the roof cannot carry a tower, or where the owner has no staff to run a treatment program, those obligations are what decide the question rather than the kilowatts. (6.3.5)

NOTE Evaporative condensing sits between the two. It rejects heat to the wet-bulb like a tower while keeping the refrigerant circuit inside one machine, so it recovers most of the efficiency advantage without a separate condenser water loop, and it inherits the water treatment and freeze protection obligations that come with an open recirculating water system. (6.3.6)

6.4 Condenser Water Conditions

6.4.1 Where the chiller is water-cooled, the condenser shall be selected for the condenser water temperatures and flow indicated in the datasheet.

Design Entering Condenser Water Temperaturerange

°F

455560657075788082859095100105

Per drawings — mechanical equipment schedule (deferred by default)

Design Leaving Condenser Water Temperaturerange

°F

5565758590929598100105110115120

Per drawings — mechanical equipment schedule (deferred by default)

Design Condenser Flow Raterange

gpm

525601252503756259001250187525003750500075001100015000

Per drawings — mechanical equipment schedule (deferred by default)

Maximum Condenser Water-Side Pressure Droprange

ft w.c.

51015202530405060

Per drawings — mechanical equipment schedule (deferred by default)

6.4.2 The condenser water flow arrangement shall be as indicated in the datasheet.

Condenser Water Flow Arrangementradio

● Constant flow through the condenser

○ Variable flow through the condenser

6.4.3 The minimum entering condenser water temperature at which the chiller can carry full load shall be stated in the submittal, and the control sequence shall not command the tower below that temperature while the chiller is loaded.

NOTE Lowering entering condenser water temperature raises chiller efficiency and lowers tower efficiency at the same time, so the plant optimum sits somewhere between the two and moves with load and wet-bulb. It is not at either end, which is why a fixed condenser water setpoint is almost always leaving energy on the table in one direction or the other. (6.4.4)

NOTE There is a floor on how far the water can be lowered. Below the machine's minimum entering temperature the pressure difference across the expansion device is too small to feed the evaporator, and the chiller starves rather than merely losing efficiency. Variable-speed centrifugal machines tolerate a considerably lower floor than fixed-speed machines, which is one of the practical reasons the two are not interchangeable on a plant designed for aggressive condenser water reset. (6.4.5)

6.5 Condenser Air Conditions

6.5.1 Where the chiller rejects heat to air, the condenser shall be selected for the entering air dry-bulb temperature indicated in the datasheet.

Design Entering Condenser Air Dry-Bulb Temperaturerange

°F

7080859095100105110115120130

Per drawings — mechanical equipment schedule (deferred by default)

6.5.2 Where the chiller rejects heat evaporatively, the condenser shall be selected for the entering air wet-bulb temperature indicated in the datasheet.

Design Entering Condenser Air Wet-Bulb Temperaturerange

°F

506065707274767880828590

Per drawings — mechanical equipment schedule (deferred by default)

6.5.3 The entering air temperature used for selection shall include an allowance for air recirculating from the condenser discharge back to the condenser inlet where the installed arrangement can produce it.

NOTE The entering air temperature at the coil is not the outdoor design temperature. A chiller in a screened well, against a parapet, or downwind of another unit takes in air the machines around it have already heated, and the difference is routinely several degrees. The design point that matters is the one at the coil face on the worst afternoon, not the one in the weather data. (6.5.4)

6.6 Fouling Allowance

6.6.1 The heat exchangers shall be selected with the fouling allowances indicated in the datasheet, and the allowance used shall be stated on the certified performance data.

Evaporator Fouling Allowancerange

h·ft²·°F/Btu

0.00010.000250.00050.000750.001

Condenser Fouling Allowancerange

h·ft²·°F/Btu

0.00010.000250.00050.000750.001

NOTE The defaults are the allowances ANSI/AHRI 550/590 applies at the standard rating conditions, which makes them correct without knowing anything about the project and makes any departure a deliberate act the submittal has to show. (6.6.2)

NOTE A fouling allowance is surface area bought in advance against future dirt, so specifying more of it makes the machine larger and the day-one approach smaller. Specifying a clean allowance of zero produces the smallest and most efficient machine on paper and one whose measured approach begins drifting away from the certified value the week it is commissioned. (6.6.3)

NOTE The two loops foul differently, which is why the two numbers differ. A closed chilled water loop that has been cleaned, treated, and kept closed stays nearly clean indefinitely, while an open condenser loop concentrates dissolved solids by evaporation and admits airborne debris continuously. That asymmetry is the reason the condenser carries the larger allowance in the rating standard. (6.6.4)

7 Energy Performance

7.1 Efficiency Compliance Path

7.1.1 Each chiller shall meet or exceed the minimum full-load and part-load efficiency that ANSI/ASHRAE/IES 90.1 requires for its compressor type, condenser type, and capacity range under the compliance path indicated in the datasheet.

ANSI/ASHRAE/IES 90.1 Efficiency Compliance Pathradio

○ Path A

○ Path B

7.1.2 The compliance path used shall be stated on the certified performance data, and the same path shall be applied to both the full-load and the part-load requirement.

NOTE ANSI/ASHRAE/IES 90.1 offers the two paths because a single pair of numbers cannot describe both a machine that runs mostly at full load and a machine that runs mostly at part load. Path A sets a tighter full-load requirement and a looser part-load requirement; Path B does the reverse. Neither is more stringent overall, and a plant that runs many hours at low load is measured more honestly by the second. (7.1.3)

NOTE This field carries no default because the answer follows from the load profile the project expects, which the template cannot know. A chiller serving a process load that runs near capacity around the clock and a chiller serving an office building that spends most of its hours below half load are described correctly by different paths. (7.1.4)

7.2 Full-Load and Part-Load Limits

7.2.1 The full-load power input per unit of capacity at the design conditions shall not exceed the value indicated in the datasheet.

Maximum Full-Load Power Inputrange

kW/ton

0.250.30.350.40.450.50.550.60.650.70.80.911.11.251.41.61.8

Per drawings — mechanical equipment schedule (deferred by default)

7.2.2 The part-load power input per unit of capacity at the design conditions shall not exceed the value indicated in the datasheet, computed by the weighting of ANSI/AHRI 550/590.

Maximum Part-Load Power Inputrange

kW/ton

0.150.20.250.30.350.40.450.50.60.70.80.911.21.5

Per drawings — mechanical equipment schedule (deferred by default)

7.2.3 The power input used to evaluate both limits shall include the compressor motor, the drive losses, the oil pump, the control power, and the condenser fans where the condenser is integral to the package.

7.2.4 Where the datasheet indicates no limit, the minimum of ANSI/ASHRAE/IES 90.1 under the selected compliance path shall govern, and the certified value shall be reported for each chiller tag.

NOTE These fields defer to the schedule rather than carrying a number because the achievable value spans a range no single default could sit inside. A large water-cooled variable-speed centrifugal machine and a small air-cooled scroll machine differ by a factor of two at full load, and both are correct selections for the buildings they serve. (7.2.5)

NOTE The part-load weighting is where most of the annual energy actually lives. ANSI/AHRI 550/590 weights the 75 and 50 percent load points far more heavily than the full-load point, because a chiller in a real building spends very few hours at its nameplate capacity. A machine chosen on full-load efficiency alone is being chosen on the operating point it will almost never see. (7.2.6)

NOTE The boundary of the measurement matters as much as the number. A part-load figure that counts only the compressor is not comparable to one that counts the condenser fans and the drive, and an air-cooled machine's fan power is a significant fraction of the total. Stating the inclusions is what makes two quotations comparable. (7.2.7)

7.3 Performance Verification and Shortfall

7.3.1 The remedy for a chiller that fails to meet its scheduled capacity or efficiency shall be as indicated in the datasheet.

Performance Shortfall Remedyselect

Correct or replace the chiller and retest at the manufacturer's cost

Correct or replace the chiller, or accept a negotiated credit at the Owner's election

Liquidated damages based on the capitalized value of the excess energy

Correct or replace the chiller, with liquidated damages if uncorrected by a stated date

7.3.2 Capacity shall be evaluated against the tolerance ANSI/AHRI 550/590 permits for the measured conditions, and the tolerance applied shall be stated with the test result.

7.3.3 Where a shortfall is found, the cost of the corrective work and of any retest shall be borne by the manufacturer.

7.3.4 Where the Engineer of Record and the manufacturer disagree whether a measured shortfall is attributable to the machine or to the conditions delivered to it, the initial determination shall be made by the Engineer of Record.

NOTE The tolerance in ANSI/AHRI 550/590 is not a discount on the guarantee. It is an allowance for the uncertainty of measuring capacity in the field, where flow, temperature, and power are each measured with their own error, and it narrows as the measurement improves. A shortfall inside the tolerance band has not been demonstrated; one outside it has. (7.3.5)

NOTE The disagreement this clause anticipates is specific and common: a machine tested at a condenser water temperature the tower could not hold, or a flow the balancing agency had not yet set, will miss its capacity for reasons that have nothing to do with the chiller. Naming who decides prevents the test from becoming a standoff. (7.3.6)

8 Refrigerant

8.1 Refrigerant Selection

8.1.1 The refrigerant shall be as indicated in the datasheet.

Refrigerantselect

R-1233zd(E)

R-514A

R-515B

R-513A

R-1234ze(E)

R-1234yf

R-454B

R-455A

R-32

R-290 propane

R-717 ammonia

R-744 carbon dioxide

R-134a

R-410A

8.1.2 The refrigerant furnished shall be listed for the equipment's end use under 40 CFR Part 84 at the date of manufacture, and the submittal shall state the global warming potential of the refrigerant and the regulatory end-use category claimed.

8.1.3 The refrigerant furnished shall carry a designation and safety group classification assigned under ANSI/ASHRAE 34.

8.1.4 The maximum global warming potential permitted for the project shall be as indicated in the datasheet.

Maximum Refrigerant Global Warming Potentialrange

1015030050070075015002100

8.1.5 Where the datasheet indicates no maximum global warming potential, the limit applicable to the equipment's end use under 40 CFR Part 84 shall govern.

NOTE This field lists every refrigerant a project could legitimately specify in a liquid chiller in this market, including several that federal rules no longer permit in new comfort-cooling equipment, because the standard's scope reaches process duty where different end-use categories and dates apply and because replacement and rebuild work occurs under the original refrigerant. The clause above, not the option list, is what enforces the applicable limit. (8.1.6)

NOTE The choice divides first on operating pressure rather than on global warming potential. R-1233zd(E), R-514A, and R-515B run at low pressure, which permits thin-walled shells and very large centrifugal impellers but puts the machine in vacuum at part load, so every leak admits air and moisture and the machine needs a purge unit to remove them. The medium-pressure refrigerants stay above atmospheric throughout, so a leak loses charge instead of gaining contamination. (8.1.7)

NOTE The second division is flammability. The A2L refrigerants that reach the lowest global warming potential at medium pressure carry a mild flammability that brings UL 60335-2-40 construction, charge limits, leak detection, and in some jurisdictions additional room requirements with them. That is a real set of obligations rather than a disqualification, and it is the reason the A1 low-pressure refrigerants remain in wide use on large machines. (8.1.8)

NOTE Ammonia and carbon dioxide sit outside both patterns. Ammonia has no global warming potential worth measuring and excellent thermodynamic properties, and it is toxic and incompatible with copper, so a machine using it is built of steel and normally sits in a dedicated room with its own detection. Carbon dioxide operates transcritically at ordinary condensing temperatures, which changes the cycle rather than only the fluid. (8.1.9)

8.2 Refrigerant Safety Group Policy

8.2.1 The refrigerant safety groups permitted for the project shall be as indicated in the datasheet, and the refrigerant selected shall fall within one of them.

Permitted Refrigerant Safety Groupscheckbox

☑ A1

☑ A2L

☐ A2

☐ A3

☐ B1

☐ B2L

☐ B2

8.2.2 Where a refrigerant in a flammable safety group is furnished, the chiller shall be listed under UL 60335-2-40 with the flammable refrigerant provisions applied, and the charge limits, ventilation, and detection that listing requires shall be provided.

8.2.3 Where a refrigerant in a higher-toxicity safety group is furnished, the machinery room, detection, and ventilation requirements ANSI/ASHRAE 15 assigns to that group shall be provided.

NOTE The safety group is a policy decision separate from the refrigerant itself, and it is often made by the Owner or the Authority Having Jurisdiction rather than by the designer. Setting it in the datasheet lets a project state the constraint once and have every refrigerant question resolve against it, instead of discovering at submittal review that the selected machine falls outside a rule nobody wrote down. (8.2.4)

8.3 Refrigerant Charge Isolation and Recovery

8.3.1 Provisions for isolating and recovering the refrigerant charge shall be as indicated in the datasheet.

Refrigerant Isolation and Recovery Provisionscheckbox

☑ Service valves isolating the compressor from the circuit

☐ Service valves permitting the charge to be pumped into the condenser

☐ Integral pumpout compressor and storage vessel

☐ Refrigerant storage vessel without a pumpout compressor

☑ Access ports sized for external recovery equipment

8.3.2 A purge unit shall be furnished where the machine operates below atmospheric pressure at any condition within its operating range.

8.3.3 Where a purge unit is furnished, it shall log purge run time and shall report accumulated purge time to the unit controller.

NOTE Purge run time is the most sensitive leak indicator a low-pressure machine has. Air and moisture entering through a leak are removed by the purge, so a rising purge run time reports a growing leak long before the machine loses performance and long before a conventional leak test would find it. Logging it turns a maintenance nuisance into an instrument. (8.3.4)

NOTE Isolation provisions decide what a compressor overhaul costs. A machine whose charge can be pumped into its own condenser is serviced by closing two valves; a machine without them requires the entire charge to be recovered into cylinders, stored, and returned, which on a large centrifugal is a multi-day operation with its own loss and contamination risk. (8.3.5)

8.4 Pressure Relief

8.4.1 Pressure relief devices shall be furnished on every pressure vessel and on every section of the refrigerant circuit that can be isolated while containing liquid refrigerant, sized and set in accordance with ANSI/ASHRAE 15.

8.4.2 The relief discharge arrangement shall be as indicated in the datasheet.

Relief Discharge Arrangementselect

Piped to the outdoors and terminated in accordance with ANSI/ASHRAE 15

Piped to the outdoors through a rupture disc and relief valve assembly with pressure indication between them

Piped to a refrigerant treatment or diffusion system

Discharged within the machinery room

8.4.3 Discharge within the machinery room shall be used where the refrigerant quantity, the room volume, and the ventilation rate satisfy ANSI/ASHRAE 15 for the refrigerant furnished, and shall not be used otherwise.

8.4.4 Dual relief devices with a three-way transfer valve shall be furnished where the machine must remain in service while a relief device is replaced.

8.4.5 The relief vent piping size, material, and maximum equivalent length shall be as calculated under ANSI/ASHRAE 15 for the discharge capacity of the devices furnished, and the calculation shall be submitted.

NOTE The rupture disc placed upstream of a relief valve on a low-pressure machine exists to keep the valve from leaking a vacuum-side machine to atmosphere, and the pressure gauge between the two is what tells an operator the disc has failed. Without that gauge a burst disc is invisible until the relief valve itself lifts. (8.4.6)

NOTE Relief vent piping is sized by the pressure the discharging device can tolerate at its outlet rather than by the pipe that fits. Adding length or fittings to a vent that was calculated for a shorter run raises that back pressure, and past the calculated limit the device no longer relieves at its rated capacity. This is the reason the calculation is submitted rather than assumed. (8.4.7)

8.5 Refrigerant Leak Detection

8.5.1 Refrigerant leak detection shall be provided as indicated in the datasheet.

Refrigerant Leak Detectionselect

Machinery room detector conforming to ANSI/ASHRAE 15

Detector integral to the chiller package

Machinery room detector and a detector integral to the chiller package

None

8.5.2 Where a leak detector is provided, it shall alarm locally and at the building automation system, and its alarm and setpoint shall be included in the point list.

8.5.3 Where the chiller is listed under UL 60335-2-40 with the flammable refrigerant provisions applied, the mitigation actions that listing requires on a detected leak shall be executed by the unit controller independently of the building automation system.

NOTE A detector that reports only to a control system the machine does not depend on is a detector that stops working the day the network does. That is why the mitigation logic for a flammable refrigerant lives in the unit controller: the required response has to happen whether or not anything outside the machine is listening. (8.5.4)

9 Compressor

9.1 Compressor Type

9.1.1 The compressor type shall be as indicated in the datasheet.

Compressor Typeselect

Centrifugal

Twin-screw

Single-screw

Scroll

Reciprocating

9.1.2 The number of compressors furnished on each chiller shall be as indicated in the datasheet.

Number of Compressors per Chillerrange

1234568

9.1.3 The number of independent refrigerant circuits furnished on each chiller shall be as indicated in the datasheet.

Number of Independent Refrigerant Circuitsrange

123456

9.1.4 The submittal shall state the number of compression stages and, for a screw compressor, whether the volume ratio is fixed or variable.

NOTE Compressor type carries no default because the machine types occupy overlapping capacity ranges and are chosen on different grounds. Centrifugal compression moves large volumes efficiently and its efficiency improves as lift falls, which is why it dominates large water-cooled plants. Screw compression is positive displacement, so it holds capacity as lift rises and tolerates the high condensing temperatures an air-cooled machine sees on a hot afternoon. (9.1.5)

NOTE Scroll and reciprocating machines are built from multiple small compressors rather than one large one, which gives them capacity control by staging and a redundancy the single-compressor machines do not have. The tradeoff is that staging produces a sawtooth in part-load efficiency rather than the smooth curve continuous modulation gives. (9.1.6)

NOTE Independent refrigerant circuits are the redundancy decision. A chiller with two circuits keeps roughly half its capacity after a compressor failure or a refrigerant leak, and does so without a second machine, a second set of connections, or a second footprint. It also costs a second set of everything inside the shells and gives up some of the efficiency a single large circuit reaches. (9.1.7)

9.2 Compressor Bearings and Lubrication

9.2.1 The compressor bearing arrangement shall be as indicated in the datasheet.

Compressor Bearing Arrangementselect

Oil-lubricated hydrodynamic journal and thrust bearings

Oil-lubricated rolling-element bearings

Refrigerant-lubricated bearings

Magnetic bearings, oil-free

9.2.2 Where an oil-lubricated compressor is furnished, the lubrication system shall include an oil charge, an oil filter, an oil level indication or sensor, and oil temperature and pressure monitoring reported to the unit controller.

9.2.3 Where an oil-lubricated compressor is furnished, an oil heater shall be provided and shall be energized whenever the compressor is not running.

9.2.4 Where an oil-free compressor is furnished, the submittal shall state the bearing lift-off and touchdown behavior on loss of power and the number of coast-down events the backup bearings are rated for.

NOTE Oil is the reason a large fraction of chiller maintenance exists. It has to be kept warm so refrigerant does not dissolve into it during standby, filtered so bearing surfaces survive, analyzed to catch wear before it becomes damage, and separated from refrigerant so it does not coat the evaporator tubes and cost heat transfer. Removing it removes that whole category of work. (9.2.5)

NOTE What an oil-free magnetic bearing machine substitutes is a dependence on power electronics and on a controlled shutdown. The rotor is held by an active magnetic field, so a loss of power drops it onto backup bearings, and those bearings have a rated number of such events rather than an indefinite life. The question to ask a supplier is what that number is and what the machine does during an ordinary utility outage. (9.2.6)

9.3 Compressor Speed Control and Capacity Modulation

9.3.1 The compressor speed control arrangement shall be as indicated in the datasheet.

Compressor Speed Controlradio

○ Variable speed on the compressor motor

○ Fixed speed

9.3.2 The means by which the chiller modulates capacity below full load shall be as indicated in the datasheet.

Compressor Capacity Modulation Meanscheckbox

☐ Variable compressor speed

☐ Inlet guide vanes

☐ Slide valve

☐ Variable volume ratio control

☐ Cylinder unloading

☐ Staging of multiple compressors

☐ Hot gas bypass

9.3.3 The minimum capacity the chiller can hold in stable continuous operation without hot gas bypass shall be as indicated in the datasheet, expressed as a percentage of the design capacity.

Minimum Stable Capacity Without Hot Gas Bypassrange

%

51015202530405060

9.3.4 Where the datasheet indicates no minimum stable capacity, the manufacturer's published minimum for the model furnished shall be stated in the submittal.

9.3.5 Where hot gas bypass is furnished, the control sequence shall not engage it above the minimum stable capacity of the machine.

NOTE Speed control and modulation are separate decisions because a machine can have both, and most modern machines do. A variable-speed centrifugal still needs guide vanes to control capacity at low lift, where slowing the impeller further would put it into surge; a variable-speed screw still uses its slide valve at the bottom of its range. Splitting the fields lets a project state what it requires without implying the other. (9.3.6)

NOTE Variable speed pays where lift falls at part load and pays very little where it does not. Compressor power follows the product of flow and lift, so a machine that unloads on a cool day with cold condenser water sees both fall together and the saving is large. A machine held at constant lift by a fixed condenser water setpoint gets almost none of that, which is why the drive and the condenser water reset sequence are effectively one decision. (9.3.7)

NOTE Hot gas bypass produces capacity turndown by wasting compressor work deliberately, which is why it belongs at the bottom of the range and nowhere else. Its legitimate purpose is to keep a machine on line below its stable minimum instead of short-cycling it, and a sequence that engages it earlier converts an efficiency problem into an energy bill. (9.3.8)

9.4 Compressor Motor and Cooling

9.4.1 The compressor motor construction shall be as indicated in the datasheet.

Compressor Motor Constructionselect

Hermetic, refrigerant-cooled

Semi-hermetic, suction-gas cooled

Semi-hermetic, refrigerant liquid cooled

Open drive with an air-cooled motor and a shaft seal

9.4.2 The compressor motor shall conform to NEMA MG 1 where it is an open-drive machine, and shall carry winding temperature sensing reported to the unit controller in every construction.

9.4.3 Where the compressor motor is driven by a variable-speed drive, its insulation system shall be rated for inverter duty in accordance with NEMA MG 1 Part 31 or shall be a drive-matched motor supplied by the chiller manufacturer as a coordinated set.

NOTE A hermetic motor cooled by its own refrigerant has no shaft seal and therefore no external leak path, which is the reason the arrangement dominates. The cost is that a motor burn contaminates the refrigerant circuit with acid and requires a full cleanup rather than a motor replacement. (9.4.4)

NOTE Open-drive construction exists because some refrigerants cannot be allowed near motor windings and some machines need a motor the owner can rewind locally. Ammonia is the usual reason: it attacks the copper in a conventional winding, so the motor stays outside the refrigerant boundary and a shaft seal takes on the containment duty instead. (9.4.5)

9.5 Compressor Service Access

9.5.1 The chiller shall be arranged so that the compressor can be removed and reinstalled without disturbing the evaporator or condenser shells.

9.5.2 Isolation valves shall permit the compressor to be removed without recovering the charge from the shells where the isolation provisions indicated in the datasheet include that capability.

9.5.3 Service ports, sensors, and the oil filter shall be reachable from the service side of the machine without removing structural members.

10 Evaporator

10.1 Evaporator Type

10.1.1 The evaporator type shall be as indicated in the datasheet.

Evaporator Typeselect

Flooded shell-and-tube

Falling-film shell-and-tube

Direct-expansion shell-and-tube

Brazed-plate

Gasketed plate-and-frame

10.1.2 The evaporator shall be selected so that the water velocity through the tubes at the design flow falls within the manufacturer's published limits for the tube material furnished.

NOTE A flooded evaporator submerges the tubes in liquid refrigerant, which gives the highest heat transfer coefficient and the smallest approach and requires the largest refrigerant charge. A direct-expansion evaporator puts refrigerant inside the tubes and water in the shell, which cuts the charge substantially and gives up some approach. Falling-film construction sprays refrigerant over the tubes to get flooded performance at a fraction of the flooded charge. (10.1.3)

NOTE Charge quantity is not a side issue when the refrigerant concentration limit decides whether the project needs a machinery room, and it is the mechanism by which evaporator type reaches back into the architecture. A falling-film machine and a flooded machine of the same capacity can land on opposite sides of that line. (10.1.4)

NOTE Plate heat exchangers reach a very small approach in very little space and tolerate almost no fouling, because the channels between plates are narrow enough to block. They suit clean closed loops and small machines, and a gasketed plate-and-frame unit can be opened and cleaned where a brazed unit cannot. (10.1.5)

10.2 Evaporator Tubes

10.2.1 Evaporator tubes shall be of the material indicated in the datasheet.

Evaporator Tube Materialselect

Enhanced copper

Copper-nickel 90-10

Copper-nickel 70-30

Titanium

Stainless steel

Carbon steel

10.2.2 The minimum evaporator tube wall thickness shall be as indicated in the datasheet.

Minimum Evaporator Tube Wall Thicknessrange

in.

0.020.0250.0280.0350.0490.065

10.2.3 Tubes shall be individually replaceable, mechanically expanded into the tube sheets, and removable from one end of the shell without cutting the shell.

10.2.4 Copper tubes shall not be used with a refrigerant or a fluid that attacks copper, and the tube material shall be confirmed compatible with both the refrigerant and the circulated fluid in the submittal.

10.2.5 Where the datasheet indicates no minimum wall thickness, the manufacturer's standard wall for the model furnished shall be stated in the submittal.

NOTE Enhanced copper is the near-universal chiller tube because a closed, treated chilled water loop is one of the least aggressive water environments in a building and copper's thermal conductivity is very high. The enhancement is a rolled internal and external surface geometry that multiplies the effective area several times over a smooth tube, which is what makes a modern chiller so much smaller than an older one of the same capacity. (10.2.6)

NOTE The copper-nickel alloys, titanium, and stainless steel appear in the list for water the closed-loop assumption does not describe: seawater, brackish or high-chloride make-up, aggressive process fluids, and loops that cannot be treated. Each buys corrosion resistance at a real cost in conductivity, so the machine gets larger for the same duty. (10.2.7)

NOTE Wall thickness is where tube life and heat transfer trade against each other directly. A thinner wall conducts better and lets the machine be smaller; it also leaves less metal to lose to erosion at the tube inlet and to the mechanical cleaning the tubes will receive over a thirty-year life. On a machine expected to be cleaned regularly, the heavier wall is what makes that survivable. (10.2.8)

10.3 Evaporator Water-Side Rating and Waterboxes

10.3.1 The evaporator water side shall be rated for the working pressure indicated in the datasheet.

Evaporator Water-Side Design Working Pressurerange

psig

150300450600

10.3.2 The evaporator waterbox arrangement shall be as indicated in the datasheet.

Evaporator Waterbox Arrangementselect

Bolted marine waterbox

Bolted compact waterbox with nozzles in the head

Welded waterbox with bolted access covers

10.3.3 Waterboxes shall be furnished with vent and drain connections at the high and low points of each water pass.

10.3.4 Where the static pressure at the chiller can exceed the rated working pressure while the system is shut down, that static pressure shall be included in the working pressure used to select the waterbox rating.

NOTE A marine waterbox lets the head be removed for tube access without breaking the water piping, because the nozzles are on the shell rather than on the head. On a machine at the end of a tight mechanical room, that difference is what makes a tube cleaning a one-day job instead of a piping project, and it is worth more the harder the machine is to reach. (10.3.5)

NOTE Static pressure is the trap on tall buildings. A chiller in a basement plant serving a twenty-story riser sees the full water column whether the pumps run or not, and the 150 psig waterbox that is entirely adequate in a two-story building is below its rating there before the machine has even started. (10.3.6)

10.4 Evaporator Water Connections

10.4.1 Evaporator water connections shall be of the type indicated in the datasheet.

Evaporator Water Connection Typeselect

Flanged, ASME B16.1 Class 125

Flanged, ASME B16.1 Class 250

Flanged, ASME B16.5 Class 150

Flanged, ASME B16.5 Class 300

Grooved end

Victaulic-style shouldered end

Threaded, NPT

10.4.2 Gasket, bolting, and mating flange requirements at the chiller connections shall conform to Hydronic PipingHydronic PipingResolves to the current edition.sync/hydronic-piping.

10.4.3 The connection type and the waterbox pressure rating shall be compatible, and the lower of the two shall govern the system working pressure at the chiller.

10.5 Evaporator Flow Range and Flow Proving

10.5.1 The evaporator flow arrangement shall be as indicated in the datasheet.

Evaporator Flow Arrangementradio

○ Constant flow through the evaporator

○ Variable flow through the evaporator

10.5.2 The minimum evaporator flow at which the chiller can operate continuously shall be as indicated in the datasheet, expressed as a percentage of the design flow.

Minimum Continuous Evaporator Flowrange

%

2025304050607080100

10.5.3 Where variable evaporator flow is indicated, the submittal shall state the maximum rate of change of evaporator flow the machine tolerates, expressed as a percentage of design flow per minute.

10.5.4 A flow proving device shall be furnished at the evaporator as indicated in the datasheet and shall be interlocked with the unit controller to prevent compressor operation without flow.

Evaporator Flow Proving Methodselect

Thermal dispersion flow switch furnished by the chiller manufacturer

Paddle-type flow switch furnished by the chiller manufacturer

Differential pressure switch across the evaporator

Flow meter signal from the building automation system

Field-furnished flow switch wired to the unit controller

10.5.5 Pump status shall not be used as the sole proof of evaporator flow.

NOTE The freeze risk is what makes flow proving non-negotiable. A compressor that keeps running against a stagnant evaporator pulls the refrigerant temperature down until the water in the tubes freezes, and the expanding ice splits the tubes and floods the refrigerant circuit with water. That failure destroys the machine, and a running pump proves nothing about a closed valve or a blocked strainer downstream of it. (10.5.6)

NOTE Variable primary flow saves pumping energy by removing the constant-flow primary loop, and the price is a rate-of-change limit the control sequence has to respect. The chiller's capacity control loop is tuned to a certain thermal mass moving past its sensor, and changing that flow faster than the machine's published limit sends the leaving water temperature into oscillation and eventually into a low-temperature trip. (10.5.7)

10.6 Evaporator Insulation

10.6.1 Insulation of the cold surfaces of the chiller shall be as indicated in the datasheet.

Chiller Cold Surface Insulationradio

● Factory-applied closed-cell insulation with a factory vapor seal

○ Factory-applied closed-cell insulation without a jacket

○ Field-applied insulation

○ None

10.6.2 Where the datasheet indicates field-applied insulation, that work shall conform to Mechanical InsulationMechanical InsulationResolves to the current edition.sync/mechanical-insulation.

10.6.3 The minimum insulation thickness on cold surfaces shall be as indicated in the datasheet.

Minimum Cold Surface Insulation Thicknessrange

in.

0.50.7511.522.53

10.6.4 The manufacturer shall confirm that the insulation furnished prevents surface condensation at the maximum ambient dry-bulb temperature and maximum relative humidity indicated in the datasheet.

10.6.5 Insulation shall cover the evaporator shell, the waterboxes, the suction line, and every other surface that operates below the dew point of the surrounding air.

NOTE Insulation on a chiller is vapor control rather than heat conservation. The heat gain through an inch of closed-cell foam is trivial against a machine rejecting hundreds of tons; what matters is that water vapor cannot reach the cold metal, because condensation inside the insulation destroys its thermal resistance and then corrodes the shell under a layer nobody can see. That is why the vapor seal matters more than the thickness. (10.6.6)

NOTE Thickness is set by the dew point rather than by a rule of thumb, and the governing condition is the worst humidity the space reaches rather than its design condition. An unconditioned below-grade plant on a humid summer morning is the case that decides the number. (10.6.7)

11 Condenser

11.1 Water-Cooled Condenser Construction

11.1.1 Where the chiller is water-cooled, the condenser shall be constructed as indicated in the datasheet.

Water-Cooled Condenser Constructionselect

Shell-and-tube with a removable head

Shell-and-tube with a welded head and bolted access covers

Brazed-plate

Gasketed plate-and-frame

Not applicable, the chiller rejects heat to air

11.1.2 The condenser shall include a subcooler section or an equivalent means of subcooling the liquid refrigerant, and the design subcooling shall be stated in the submittal.

NOTE Subcooling is free capacity taken at the bottom of the condenser. Liquid leaving at the saturation temperature flashes as it passes the expansion device, and the vapor produced does no cooling in the evaporator; every degree of subcooling below saturation reduces that flash and raises the net refrigerating effect for the same compressor work. (11.1.3)

11.2 Condenser Tubes

11.2.1 Condenser tubes shall be of the material indicated in the datasheet.

Condenser Tube Materialselect

Enhanced copper

Copper-nickel 90-10

Copper-nickel 70-30

Titanium

Stainless steel

Carbon steel

11.2.2 The minimum condenser tube wall thickness shall be as indicated in the datasheet.

Minimum Condenser Tube Wall Thicknessrange

in.

0.020.0250.0280.0350.0490.065

11.2.3 Condenser tubes shall be individually replaceable and removable from one end of the shell without cutting the shell.

NOTE The condenser tubes live in the harsher of the two water environments and are the tubes that actually get cleaned. An open tower loop concentrates hardness by evaporation, carries airborne debris, and supports biological growth, so condenser tubes foul on a schedule while evaporator tubes largely do not. That is the argument for the heavier wall on the condenser side even where both shells use the same alloy. (11.2.4)

NOTE Condenser approach is the most useful single diagnostic a chiller offers, because it responds almost entirely to tube cleanliness. A machine whose condenser approach has widened by two or three degrees against its commissioned value is telling the operator to clean the tubes, and the energy that cleaning recovers is usually several percent of the machine's annual consumption. (11.2.5)

11.3 Condenser Water-Side Rating and Connections

11.3.1 The condenser water side shall be rated for the working pressure indicated in the datasheet.

Condenser Water-Side Design Working Pressurerange

psig

150300450600

11.3.2 The condenser waterbox arrangement shall be as indicated in the datasheet.

Condenser Waterbox Arrangementselect

Bolted marine waterbox

Bolted compact waterbox with nozzles in the head

Welded waterbox with bolted access covers

11.3.3 Condenser water connections shall be of the type indicated in the datasheet.

Condenser Water Connection Typeselect

Flanged, ASME B16.1 Class 125

Flanged, ASME B16.1 Class 250

Flanged, ASME B16.5 Class 150

Flanged, ASME B16.5 Class 300

Grooved end

Victaulic-style shouldered end

Threaded, NPT

11.3.4 A flow proving device shall be furnished at the condenser and interlocked with the unit controller as indicated in the datasheet.

Condenser Flow Proving Methodselect

Thermal dispersion flow switch furnished by the chiller manufacturer

Paddle-type flow switch furnished by the chiller manufacturer

Differential pressure switch across the condenser

Field-furnished flow switch wired to the unit controller

Not applicable, the chiller rejects heat to air

11.3.5 Condenser waterboxes shall be furnished with cleaning access consistent with the tube cleaning method the Owner intends to use.

11.4 Air-Cooled Condenser Coil

11.4.1 Where the chiller is air-cooled, the condenser coil shall be constructed as indicated in the datasheet.

Air-Cooled Condenser Coil Constructionselect

Copper tube with aluminum fins

Copper tube with copper fins

All-aluminum microchannel

All-aluminum round tube and fin

11.4.2 The condenser coil protective coating shall be as indicated in the datasheet.

Air-Cooled Condenser Coil Coatingselect

None

Flexible epoxy immersion coating

Electrodeposited epoxy coating

Phenolic coating

Polyurethane coating

11.4.3 Coil guards or hail guards shall be furnished as indicated in the datasheet.

Condenser Coil Guardscheckbox

☐ Louvered panels enclosing the coil faces

☐ Wire mesh coil guards

☐ Hail guards

☐ Security screening around the unit base

11.4.4 The coil shall be arranged so that the full face area can be washed from the outside without dismantling the machine.

NOTE A copper tube with aluminum fins puts two dissimilar metals in contact in outdoor air, and in a chloride-bearing atmosphere the aluminum fin corrodes preferentially and separates from the tube. The fin loss is invisible from the ground and shows up as a condensing temperature that has climbed a few degrees, which costs capacity on exactly the days the machine is needed most. (11.4.5)

NOTE All-aluminum microchannel construction removes that galvanic pair and cuts both the refrigerant charge and the air-side pressure drop, because the flat tubes and brazed fins pack far more surface into the same face area. What it gives up is repairability: a damaged microchannel slab is replaced rather than patched, and its narrow ports are less tolerant of the aggressive cleaning a fouled coil sometimes needs. (11.4.6)

NOTE Coatings buy corrosion resistance at a cost in heat transfer, because every coating adds thermal resistance at the surface where the machine rejects its heat. The penalty is small on a well-applied thin coating and grows with thickness, which is why the immersion and electrodeposited systems dominate where a coating is used at all. (11.4.7)

11.5 Condenser Fans

11.5.1 Where the chiller is air-cooled or evaporatively cooled, the condenser fans shall be arranged as indicated in the datasheet.

Condenser Fan Arrangementselect

Direct-drive axial propeller fans discharging vertically

Direct-drive axial propeller fans discharging horizontally

Belt-drive axial fans

Centrifugal fans arranged for ducted discharge

Not applicable, the chiller rejects heat to water

11.5.2 Condenser fan speed control shall be as indicated in the datasheet.

Condenser Fan Speed Controlselect

Variable speed on all condenser fans

Variable speed on the lead fan with the remainder staged

Two-speed fan motors

Fixed-speed fans staged by condensing pressure

Not applicable, the chiller rejects heat to water

11.5.3 Condenser fan motors shall be furnished with integral thermal protection and shall be accessible for replacement without removing the coil.

11.5.4 Fan guards shall be furnished on every fan opening accessible without a tool.

NOTE Condenser fan power is a larger fraction of an air-cooled machine's total than most designers expect, and it is the part of the total that responds most to speed control because fan power falls with roughly the cube of speed. On a mild day when the coil needs a fraction of its design airflow, staged fixed-speed fans deliver far more air than required while variable-speed fans deliver what is needed. (11.5.5)

NOTE The counterweight is condensing pressure. Slowing the fans raises condensing temperature and therefore compressor power, so the optimum is a balance between the two rather than the lowest possible fan speed, and it is the unit controller rather than the building automation system that is positioned to find it. (11.5.6)

11.6 Evaporatively Cooled Condensers

11.6.1 Where the chiller is evaporatively cooled, the recirculating water system shall include a sump, a circulating pump, a distribution system over the condensing surface, drift eliminators, make-up water control, and a bleed or blowdown connection.

11.6.2 The recirculating water system shall be furnished with basin heaters where the minimum ambient temperature indicated in the datasheet is below freezing.

11.6.3 The recirculating water system shall be included in the building water management program required under ANSI/ASHRAE 188 and shall be treated under HVAC Water TreatmentHVAC Water TreatmentResolves to the current edition.sync/hvac-water-treatment.

NOTE An evaporatively cooled chiller carries an open recirculating water system inside the machine, which means it carries the Legionella exposure and the treatment obligation of a cooling tower without looking like one. Projects that select it to avoid a tower sometimes discover the water management program afterward, and the program applies to the machine either way. (11.6.4)

12 Power Supply and Motor Starting

12.1 Unit Electrical Supply

12.1.1 The chiller shall be furnished for the electrical supply indicated in the datasheet.

Unit Supply Voltagerange

V

20823024038046048057560023004160690013800

Per drawings — electrical drawings and panel schedules (deferred by default)

Unit Supply Phaseradio

○ Single phase, 1Φ

○ Three phase, 3Φ

Per drawings — electrical drawings and panel schedules (deferred by default)

12.1.2 Unit voltage and phase shall match the branch circuit serving the chiller as shown on the electrical documents, and any discrepancy between the mechanical schedule and the electrical documents shall be resolved before the chiller is released for fabrication.

12.1.3 The submittal shall state full-load amperes, locked-rotor or inrush amperes, minimum circuit ampacity, and maximum overcurrent protective device size for each power connection.

12.1.4 Control power shall be derived within the chiller package from a factory-installed transformer unless the datasheet indicates a separate control power source.

NOTE Voltage is a fact about the building's distribution rather than a property of the chiller, which is why it defers to the electrical documents rather than carrying a default. The recurring coordination failure is a mechanical schedule naming a nominal utilization voltage while the panel serving the machine carries another, discovered when a motor that cannot be rewound arrives on site. (12.1.5)

NOTE Medium voltage appears in the list because it is a real and sometimes unavoidable answer on very large centrifugal machines, where the full-load current at 480 V would demand a service and a starter that cost more than the voltage change. It also brings medium-voltage maintenance, clearances, and qualified-person requirements the project has to be prepared for. (12.1.6)

12.2 Power Connection Arrangement

12.2.1 The power connection arrangement shall be as indicated in the datasheet.

Power Connection Arrangementradio

● Single point power connection to the unit

○ Single point power connection with a factory-installed distribution block

○ Multiple point power connections, one per compressor circuit

12.2.2 The disconnecting means furnished with the chiller shall be as indicated in the datasheet.

Unit Disconnecting Meansselect

Factory-mounted non-fused disconnect switch

Factory-mounted fused disconnect switch

Factory-mounted molded case circuit breaker

Factory-mounted circuit breaker with an adjustable electronic trip unit

None furnished with the unit, disconnecting means field-provided

12.2.3 The disconnecting means shall be capable of being locked in the open position in accordance with 29 CFR 1910.147.

12.2.4 Branch circuit protection, disconnecting means, and conductor sizing shall conform to NFPA 70 Articles 430 and 440.

NOTE A single point connection puts the whole machine behind one feeder and one device, which simplifies the electrical room and concentrates the consequence of a trip. Multiple point connections keep each compressor circuit independent all the way back to the panel, so a fault on one circuit leaves the other running, and they cost a second feeder and a second set of terminations. On a machine bought for redundancy, splitting the power is what makes the refrigerant-side redundancy actually redundant. (12.2.5)

12.3 Short-Circuit Current Rating

12.3.1 The chiller's integral electrical equipment shall carry a short-circuit current rating not less than the value indicated in the datasheet.

Short-Circuit Current Ratingrange

kA

51014182225303542506585100150200

Per drawings — available fault current as indicated on the electrical documents (deferred by default)

12.3.2 The rating shall be marked on the unit and shall appear on the submittal.

NOTE Short-circuit current rating is a project-sized electrical quantity determined by the transformer, the conductors, and the distance from the source, so it belongs to the electrical documents rather than to a default. It is also the item most often discovered late, because a machine ordered with a standard rating and installed close to a large service transformer cannot be corrected without either new equipment or a current-limiting device ahead of it. (12.3.3)

12.4 Compressor Starting

12.4.1 Where the compressor motor is fixed speed, the starting method shall be as indicated in the datasheet.

Fixed-Speed Compressor Starting Methodselect

Across the line, full voltage

Solid-state soft starter

Wye-delta, closed transition

Autotransformer reduced voltage

Primary reactor reduced voltage

Medium-voltage vacuum contactor starter

Not applicable, the compressor is driven at variable speed

12.4.2 The starter or drive shall develop sufficient torque at the reduced voltage to accelerate the compressor to full speed within the transition time the starter permits.

12.4.3 The number of compressor starts per hour the machine permits shall be stated in the submittal, and the control sequence shall enforce that limit.

NOTE Reduced-voltage starting exists to limit the inrush a large compressor draws, which on a machine several hundred tons in size can be several times its running current and can dip the building's voltage enough to be noticed. It is bought either because the utility or the emergency generator cannot absorb the inrush, or because the flicker is objectionable, and not because the machine needs it to start. (12.4.4)

NOTE Start limits matter more on a chiller than on most machines because each start floods the compressor's bearings with cold oil and, on a hermetic motor, dumps a large slug of heat into the winding. A control sequence that cycles a chiller against a small load shortens the machine's life in a way no alarm reports. (12.4.5)

12.5 Starter and Drive Location

12.5.1 The starter or variable-speed drive shall be located as indicated in the datasheet.

Starter and Drive Locationradio

● Unit-mounted and factory-wired to the compressor

○ Free-standing and remote from the unit, field-wired to the compressor

12.5.2 Where the starter or drive is unit-mounted, the field electrical work at the chiller shall be limited to the line-side power termination, the control interlocks, and the grounding connection.

12.5.3 Where the starter or drive is remote from the unit, the maximum cable length between the drive and the motor shall be stated by the manufacturer and shall be shown on the coordination drawings.

12.5.4 Where a variable-speed drive is remote from the unit, motor cable type, shielding, and grounding shall conform to HVAC Variable Frequency DrivesHVAC Variable Frequency DrivesResolves to the current edition.sync/hvac-variable-frequency-drives.

NOTE A unit-mounted drive is factory-wired, factory-tested with the motor it will drive, and covered by the chiller warranty as part of the machine, which removes the interface argument entirely. A remote drive can be placed in a cooler and more accessible room, can be standardized across a plant, and puts its heat somewhere other than the chiller. The reflected-wave and shaft-current concerns that come with cable length belong to the remote case. (12.5.5)

12.6 Harmonic Mitigation

12.6.1 Where a variable-speed drive is furnished, harmonic mitigation shall be as indicated in the datasheet.

Variable-Speed Drive Harmonic Mitigationselect

None

Line reactor

DC link choke

Passive harmonic filter

Active harmonic filter

Eighteen-pulse rectifier

Active front end rectifier

Not applicable, the compressor is driven at fixed speed

12.6.2 The submittal shall state the total demand distortion the drive produces at the design operating point, calculated at the point of common coupling identified by the Engineer of Record.

12.6.3 Total demand distortion at the point of common coupling shall not exceed the limit indicated in the datasheet.

Maximum Total Demand Distortion at the Point of Common Couplingrange

%

35810121520

12.6.4 Where the datasheet indicates no distortion limit, the applicable limit of IEEE 519 for the short-circuit ratio at the point of common coupling shall govern.

NOTE IEEE 519 sets its limits at the point of common coupling with the utility rather than at the drive terminals, and the permitted distortion depends on how stiff the supply is at that point. The consequence is that the same drive is compliant in one building and not in another, and that a mitigation decision made without knowing the short-circuit ratio is a guess. (12.6.5)

NOTE The mitigation options differ in what they cost to run rather than only to buy. A line reactor or DC link choke costs a fraction of a percent in losses and removes the worst of the distortion; an eighteen-pulse rectifier removes far more and carries a transformer and its losses continuously; an active front end removes most of it and can correct power factor, at the highest first cost. (12.6.6)

12.7 Electrical Enclosure and Safety

12.7.1 The unit power and control enclosure shall carry the NEMA 250 rating indicated in the datasheet.

Unit Electrical Enclosure Ratingselect

NEMA 250 Type 1

NEMA 250 Type 3R

NEMA 250 Type 4

NEMA 250 Type 4X

NEMA 250 Type 12

12.7.2 The enclosure shall be furnished with an arc-flash warning label carrying the incident energy and boundary determined for the installed condition, coordinated with Mechanical IdentificationMechanical IdentificationResolves to the current edition.sync/mechanical-identification.

12.7.3 Equipment grounding and bonding shall conform to Grounding And BondingGrounding and Bonding for Electrical SystemsResolves to the current edition.sync/grounding-and-bonding and to NFPA 70.

12.7.4 Space heaters shall be furnished in the electrical enclosure where the chiller is installed outdoors or where the enclosure can fall below the dew point of the surrounding air.

13 Unit Controls and Building Automation

13.1 Unit Controller

13.1.1 Each chiller shall be furnished with a factory-installed and factory-tested microprocessor controller that operates the machine independently of any external control system.

13.1.2 The unit controller shall provide the capabilities indicated in the datasheet.

Unit Controller Capabilitiescheckbox

☑ Local graphic display with the operating state and all sensor values

☑ Adjustable leaving chilled water temperature setpoint

☑ Adjustable demand limit setpoint

☐ Time-of-day scheduling resident in the controller

☑ Alarm and event history retained in the controller

☐ Trend logging of operating data retained in the controller

☑ Password protection of service parameters

☑ Soft load limiting on a start after an extended shutdown

☑ Automatic restart after a power interruption

☐ Service diagnostic screens with sensor calibration

13.1.3 The alarm and event history retained in the controller shall cover not less than the period indicated in the datasheet.

Minimum Retained Alarm and Event Historyrange

days

714306090180365

13.1.4 The controller shall continue to protect the machine and to hold its leaving water temperature setpoint when communication with the building automation system is lost.

NOTE The value of controller-resident history is that it survives the network. A chiller that trips at two in the morning and restarts leaves no trace in a building automation system that was polling every fifteen minutes, and the sequence of events inside the controller is often the only record of what actually happened. (13.1.5)

NOTE Automatic restart after a power interruption is a genuine choice rather than an obvious one. It returns cooling without an operator on a site that has none, and it also means a machine can start into a system whose pumps and tower have not yet been proven, which is why the restart logic has to re-verify flow rather than assume it. (13.1.6)

13.2 Protective Shutdowns and Safeties

13.2.1 The unit controller shall shut the machine down and annunciate the cause for each of the conditions indicated in the datasheet.

Protective Shutdownscheckbox

☑ Low evaporator refrigerant temperature or pressure

☑ High condenser refrigerant pressure

☑ Loss of evaporator flow

☐ Loss of condenser flow

☑ Low oil pressure or loss of oil flow

☑ High compressor motor winding temperature

☑ Compressor motor overcurrent

☑ Phase loss, phase reversal, or phase imbalance

☑ High compressor discharge temperature

☑ Low chilled water temperature

☑ Excessive compressor starts per hour

☐ Refrigerant leak detected

☑ Drive fault

13.2.2 Each protective shutdown shall be recorded in the controller's event history with a time stamp and with the sensor values at the moment of the trip.

13.2.3 The high condenser pressure protection shall be a mechanical device independent of the controller in addition to any control-based limit.

13.2.4 Phase reversal protection shall be provided on every machine whose compressor is damaged by reverse rotation.

NOTE A single high-pressure protection that depends on the controller reading a transducer has one failure mode too many, which is why a mechanical device is required alongside it. The mechanical switch does not need the controller to be running, to be calibrated, or to be scanning at the moment the pressure rises. (13.2.5)

NOTE The low chilled water temperature trip and the low evaporator refrigerant temperature trip both guard against the same outcome from opposite sides, and neither substitutes for the flow proving interlock. Freezing an evaporator is the single most expensive failure this machine has, and it is guarded three ways deliberately. (13.2.6)

13.3 Chilled Water Setpoint Reset

13.3.1 The leaving chilled water temperature reset strategy shall be as indicated in the datasheet.

Leaving Chilled Water Temperature Resetselect

None, fixed setpoint

Reset from return chilled water temperature

Reset from outdoor air temperature

Reset from the terminal with the greatest demand, commanded by the building automation system

Reset commanded by the building automation system on its own logic

13.3.2 The reset range and the rate at which the setpoint may change shall be stated in the submittal and shall be within the limits the machine tolerates.

13.3.3 Where reset is commanded externally, the unit controller shall clamp the received setpoint within the range indicated in the datasheet.

Minimum Permitted Leaving Chilled Water Setpointrange

°F

2026323638404244465055

Maximum Permitted Leaving Chilled Water Setpointrange

°F

40454850525558606570

NOTE Raising the chilled water setpoint reduces lift and therefore compressor power, and it simultaneously reduces the capacity of every coil in the building and the dehumidification those coils perform. Reset is therefore only safe where something in the control system knows whether any terminal is still asking for more cooling, which is what separates a demand-based reset from an outdoor-air reset that guesses. (13.3.4)

NOTE The clamp exists because an external system can send a number the machine cannot make. A setpoint below the freeze protection of the fluid, or above the range the expansion device can control against, produces a trip rather than an error message, and the clamp turns a bad command into a bounded one. (13.3.5)

13.4 Demand Limiting

13.4.1 Demand limiting shall be provided as indicated in the datasheet.

Chiller Demand Limitingselect

Not required

Demand limit setpoint commanded by the building automation system

Demand limit by a hardwired analog signal

Demand limit by a schedule resident in the unit controller

Demand limit by a hardwired contact from the utility or the generator control

13.4.2 Where demand limiting is provided, the chiller shall reduce capacity to hold the commanded limit and shall not shut down on reaching it.

13.4.3 Where the chiller is served by an emergency or standby generator, the demand limit that applies while on generator power shall be stated in the submittal.

NOTE The generator case is the one that most often gets designed after the fact. A chiller that draws its full load current the moment it restarts on a generator sized for the building's average demand will trip the generator, and the fix is a demand limit that engages on the transfer signal rather than a larger generator. (13.4.4)

13.5 Multiple-Chiller Sequencing

13.5.1 Responsibility for sequencing multiple chillers shall be as indicated in the datasheet.

Multiple-Chiller Sequencing Responsibilityselect

Building automation system

Factory chiller plant controller furnished with the chillers

Unit controllers communicating with each other over a manufacturer network

Not applicable, single chiller plant

13.5.2 Where the building automation system sequences the plant, that sequence shall be developed and commissioned under Building Automation SystemBuilding Automation SystemResolves to the current edition.sync/building-automation-system.

13.5.3 Where a factory plant controller is furnished, its point list, its sequence of operation, and its interface to the building automation system shall be submitted before fabrication.

NOTE Sequencing responsibility is worth naming explicitly because it is the interface most likely to be assumed by both parties and provided by neither. A factory plant controller knows the machines intimately and the building not at all; a building automation system knows the loads and has to be told everything about the machines. Both work, and neither works when each expects the other to stage the plant. (13.5.4)

13.6 Building Automation Interface

13.6.1 The chiller shall communicate with the building automation system over the protocol indicated in the datasheet, and shall be integrated under Building Automation SystemBuilding Automation SystemResolves to the current edition.sync/building-automation-system.

Building Automation Communication Protocolselect

BACnet/IP over Ethernet

BACnet MS/TP over RS-485

Modbus TCP over Ethernet

Modbus RTU over RS-485

LonWorks

Hardwired points without a communication interface

13.6.2 The points listed in the datasheet shall be made available at the building automation system.

Chiller Points at the Building Automation Systemcheckbox

☑ Run status

☑ Start and stop command

☑ Alarm status with the alarm code

☑ Leaving chilled water temperature

☑ Entering chilled water temperature

☑ Leaving condenser fluid temperature

☑ Entering condenser fluid temperature

☑ Leaving chilled water temperature setpoint, read and write

☑ Percent of full load amperes

☐ Compressor motor current

☑ Compressor motor power

☑ Evaporator refrigerant pressure and saturation temperature

☑ Condenser refrigerant pressure and saturation temperature

☐ Oil pressure and oil temperature

☑ Compressor run hours and start count

☑ Demand limit setpoint, read and write

☐ Chilled water flow

☐ Refrigerant leak alarm

☐ Purge run time

13.6.3 The communication interface shall be a native protocol interface rather than a translating gateway unless the datasheet indicates otherwise.

13.6.4 A protocol object list shall be submitted identifying every point by its object identifier, its units, and whether it is readable, writable, or both.

NOTE The four water temperatures and the two refrigerant saturation temperatures together give the two approaches, and the approaches are what turn a trend log into a maintenance program. A plant that trends only kilowatts and leaving water temperature can see that a machine is using more energy and cannot see why. (13.6.5)

NOTE A translating gateway adds a device that can fail, a mapping that can drift from the machine's actual point list, and a support boundary between two vendors. It is sometimes the only way to reach an older machine, and on new equipment a native interface removes all three problems. (13.6.6)

14 Sound

14.1 Sound Rating Basis

14.1.1 Sound power data shall be measured and reported in accordance with ANSI/AHRI 575 for chillers installed indoors and in accordance with ANSI/AHRI 370 for chillers installed outdoors.

14.1.2 Sound power data shall be reported by octave band from 63 Hz through 8,000 Hz at full load and at the part-load points used for the part-load rating.

NOTE Reporting a single A-weighted number for a chiller hides the information a designer needs, because the machine's acoustic problem is almost never broadband. A centrifugal compressor puts most of its energy into a few high-frequency tones and an air-cooled machine's fans put theirs low, and the mitigation that works on one does nothing for the other. (14.1.3)

NOTE Part-load sound is not simply quieter. A variable-speed machine slowing its compressor moves its tones down in frequency, and a chiller that is unobjectionable at full load can produce a low-frequency tone at forty percent speed that carries through structure into spaces the full-load data said were fine. (14.1.4)

14.2 Sound Limits

14.2.1 The sound power level of each chiller shall not exceed the value indicated in the datasheet.

Maximum Sound Power Level at Full Loadrange

dB

6065707580859095100105110115

Per drawings — acoustic criteria as indicated on the contract documents (deferred by default)

14.2.2 Where the datasheet indicates no sound power limit, the manufacturer's published octave band data shall be submitted and shall be evaluated by the Engineer of Record against the project's acoustic criteria.

14.2.3 Where a sound limit is indicated, the manufacturer shall state which mitigation provisions were included to reach it.

14.3 Sound Mitigation

14.3.1 Sound mitigation provisions shall be furnished as indicated in the datasheet.

Sound Mitigation Provisionscheckbox

☐ Acoustic blanket over the compressor

☐ Acoustic treatment on the compressor discharge line

☐ Enclosure over the compressor and drive

☐ Full acoustic enclosure over the machine

☐ Reduced-speed condenser fans

☐ Condenser fan speed control with a night setback limit

☐ Low-frequency attenuation on the condenser discharge

14.3.2 Where an enclosure is furnished, it shall be removable in sections without disturbing piping or conduit, and it shall not obstruct the service access this standard requires.

NOTE An acoustic enclosure that has to be unbolted as a unit to reach an oil filter is an enclosure that will be left off after the first service visit. Sectional removability is what determines whether a mitigation measure is still in place five years later, and it costs almost nothing to specify at the time of purchase. (14.3.3)

15 Heat Recovery and Free Cooling

15.1 Heat Recovery

15.1.1 Heat recovery from the chiller shall be as indicated in the datasheet.

Chiller Heat Recoveryselect

None

Desuperheater recovering sensible heat from the discharge gas

Dedicated heat recovery condenser bundle

Full condensing heat recovery replacing the heat rejection condenser

Simultaneous cooling and heating with independent evaporator and condenser water loops

15.1.2 Where heat recovery is furnished, the recovered heat quantity, the leaving hot water temperature, and the effect on cooling capacity and power input shall be stated at the design conditions.

15.1.3 Where heat recovery is furnished, the control sequence shall state which of the two loads has priority and what the machine does when they conflict.

NOTE A desuperheater takes only the sensible heat above the condensing temperature, which is a small fraction of the total rejected heat and comes at almost no penalty because it does not raise condensing pressure. A full heat recovery condenser takes the whole load and does so by condensing at the hot water temperature, which raises lift substantially and costs cooling efficiency in proportion. (15.1.4)

NOTE The priority question is where heat recovery installations most often disappoint. A machine controlled to satisfy a heating load runs its condensing temperature up and loses cooling capacity; a machine controlled to satisfy cooling delivers heat only when there is a cooling load to reject. Both are defensible and they are not the same building system, so the sequence has to say which one was bought. (15.1.5)

15.2 Waterside Free Cooling

15.2.1 Waterside free cooling shall be provided as indicated in the datasheet.

Waterside Free Coolingselect

None

Integral refrigerant migration free cooling within the chiller

Integral plate heat exchanger free cooling within the chiller

Separate plate-and-frame heat exchanger outside the chiller package

15.2.2 Where a separate plate-and-frame heat exchanger is indicated, it shall be furnished and installed under Hydronic PipingHydronic PipingResolves to the current edition.sync/hydronic-piping rather than by the chiller manufacturer.

15.2.3 Where free cooling is furnished within the chiller, the capacity available at the free cooling changeover condition and the condenser water temperature at which changeover occurs shall be stated in the submittal.

15.2.4 Where free cooling is furnished, the transition between mechanical cooling and free cooling shall be automatic and shall not require the machine to be stopped.

NOTE Refrigerant migration free cooling uses the machine's own refrigerant as a thermosiphon, moving heat from the evaporator to the condenser without running the compressor when the condenser water is cold enough. It delivers a fraction of the machine's rated capacity rather than all of it, which is the number that decides whether the feature earns its cost on a given load profile. (15.2.5)

16 Vibration Isolation and Seismic Restraint

16.1 Vibration Isolation

16.1.1 Vibration isolation shall be as indicated in the datasheet.

Chiller Vibration Isolationselect

Restrained spring isolators

Freestanding spring isolators

Concrete inertia base on spring isolators

Elastomeric isolators

Isolation pads

Direct mounting on the housekeeping pad

16.1.2 Isolators shall be selected for a static deflection not less than the value indicated in the datasheet at the operating weight of the machine.

Minimum Isolator Static Deflectionrange

in.

0.10.250.50.7511.522.53.5

16.1.3 Where the chiller is isolated, water piping and conduit at the machine shall be arranged so that the machine carries no piping weight and so that the isolators are free to deflect.

NOTE Isolator selection compares the isolator's natural frequency to the lowest forcing frequency the machine produces, and useful isolation begins only when the forcing frequency is several times the natural frequency. A centrifugal machine turning at high speed is easy to isolate; a screw machine with a low-frequency gas pulsation and a chiller on a long-span floor are the cases that need the larger deflection. (16.1.4)

NOTE The most common way a good isolation design fails is rigid piping. A machine floating on two-inch springs that is bolted to hard-piped connections is not isolated at all, because the piping is a short-circuit path straight into the structure. (16.1.5)

16.2 Seismic Restraint

16.2.1 Seismic restraint shall be provided as indicated in the datasheet.

Seismic Restraintradio

○ Required

○ Not required

Per drawings — seismic design criteria as indicated on the structural drawings (deferred by default)

16.2.2 Where seismic restraint is required, restraints shall be designed for the forces determined under ASCE/SEI 7 and the IBC using the seismic design category and component importance factor established by the Engineer of Record for the project.

16.2.3 Restraints shall permit the vibration isolators to function normally under operating conditions and shall limit motion during a seismic event so that attached piping, conduit, and the machine are not damaged.

16.2.4 Restraint calculations and attachment details shall be prepared and stamped by a professional engineer registered in the project jurisdiction.

NOTE The seismic design category and the component importance factor are determined for the building as a whole rather than chosen equipment by equipment, which is why this standard takes them as given. The importance factor follows from the building's risk category and from whether the cooling system is designated as required to function after an event, and a chiller in a hospital and a chiller in an office of the same size are not restrained the same way. (16.2.5)

17 Factory Testing

17.1 Production Tests

17.1.1 Each chiller shall be pressure tested, evacuated, dehydrated, and leak tested by the manufacturer before shipment.

17.1.2 Each chiller shall be given a factory run test verifying compressor rotation, control operation, protective device operation, and the absence of abnormal noise or vibration.

17.1.3 Factory test documentation shall be furnished as indicated in the datasheet.

Factory Test Documentation Requiredcheckbox

☑ Pressure vessel test certificate

☑ Refrigerant circuit leak test certificate

☐ Evacuation and dehydration record

☑ Factory run test report

☑ Controller point-to-point verification report

☐ Material certificates for the pressure vessels

☐ Motor test report

17.2 Factory Performance Test

17.2.1 A factory performance test shall be conducted as indicated in the datasheet.

Factory Performance Testselect

Not required, certified rating data submitted

Unwitnessed test at the design point

Unwitnessed test at the design point and the part-load points

Witnessed test at the design point

Witnessed test at the design point and the part-load points

17.2.2 Where a factory performance test is required, it shall be conducted in accordance with ANSI/AHRI 550/590 at the scheduled design conditions, and the test report shall state the measured capacity, power input, flow rates, temperatures, and the tolerance applied.

17.2.3 Where a tested chiller falls outside the tolerance, the manufacturer shall correct or replace the machine and retest it, and the cost of the retest shall be borne by the manufacturer.

17.2.4 Where the factory test facility cannot reproduce the scheduled conditions, the manufacturer shall state the conditions it can produce and the method by which the results are corrected to the design point, and that method shall be accepted before the test is scheduled.

NOTE A factory performance test on a chiller is a far more meaningful exercise than on most equipment, because a chiller test stand can hold the water temperatures and flows steady in a way a building never can. It is the only opportunity to measure the machine's capacity against its guarantee under conditions clean enough for the measurement to mean something. (17.2.5)

NOTE The correction method is the item to settle before the test rather than after. Test stands are limited in the lift and the flow they can produce, and a result corrected from the conditions the stand could reach to the conditions the project scheduled is only as good as the correction, which is a calculation the manufacturer performs on its own machine. (17.2.6)

17.3 Test Witnessing

17.3.1 Where a witnessed test is required, the Contractor shall give not less than fifteen business days written notice of the scheduled test and shall submit the test procedure and the duty points to be verified with that notice.

17.3.2 Where a witnessed test is postponed by the manufacturer after notice has been given, the manufacturer shall bear the witnesses' rescheduling costs.

17.3.3 The instruments used shall be identified in the test report with their calibration dates, and calibration shall be traceable to a national standard.

NOTE Witnessing buys something specific: it puts the design team in the room at the moment a machine misses, where the conversation about tolerance, correction method, and remedy happens in an afternoon rather than over six weeks of correspondence. It costs travel and factory scheduling, which is why it concentrates on the largest machines and on plants that cannot be taken out of service to correct a bad selection later. (17.3.4)

18 Installation

18.1 Setting and Anchoring

18.1.1 Chillers shall be set on housekeeping pads detailed housekeeping pad details as indicated on the contract documents and constructed under Concrete PadsConcrete Equipment PadsResolves to the current edition.sync/concrete-pads.

18.1.2 Housekeeping pads shall extend not less than 4 in. beyond the machine footprint on all sides and shall stand not less than 4 in. above the surrounding finished floor.

18.1.3 The machine shall be leveled within the manufacturer's published tolerance in both axes before it is anchored, and the levelness shall be recorded.

18.1.4 Anchor bolts shall be sized and embedded for the operating weight and, where seismic restraint is required, for the seismic forces determined under ASCE/SEI 7.

18.1.5 Post-installed anchors shall be qualified for the substrate and for cracked concrete where the design requires it.

18.1.6 The structural capacity of the supporting floor or roof shall be verified against the operating weight of the machine before it is set.

NOTE Levelness on a chiller is not cosmetic. A flooded evaporator's refrigerant level, an oil sump's level sensor, and a condenser's subcooler all depend on the machine sitting the way the designer assumed, and a shell out of level along its length puts refrigerant where the level control is not looking. (18.1.7)

18.2 Service and Tube Removal Clearance

18.2.1 Clearance shall be maintained around each chiller for tube removal, compressor removal, control panel access, and the electrical working space NFPA 70 requires, chiller service clearances as indicated on the mechanical plans.

18.2.2 The tube removal arrangement shall be as indicated in the datasheet.

Tube Removal Arrangementselect

Full tube length clearance at one end of the shells

Full tube length clearance at either end of the shells

Reduced clearance using the manufacturer's split tube provisions

Not applicable, plate-type heat exchangers

18.2.3 Clearances shall be not less than the manufacturer's published requirement for the model furnished, and where the manufacturer's requirement and the electrical working space differ, the greater shall govern.

18.2.4 Where the Engineer of Record and the Contractor disagree whether the clearance as built is adequate for tube removal, the initial determination shall be made by the Engineer of Record.

NOTE Tube pull space is the clearance most often consumed during construction and the hardest to recover. It is a volume the length of the shells, occupied by nothing for the life of the building, and every other trade sees it as available. Once a duct main or a pipe rack crosses it, retubing the machine means cutting that work out, which is why it belongs on the coordination drawings rather than in a note. (18.2.5)

NOTE The split tube provision some manufacturers offer trades a shorter pull space for a joint in every tube, and it is what makes a machine serviceable in a room that cannot give up the full length. It is a decision made at purchase rather than later, because the shells are built for it. (18.2.6)

18.3 Water Piping Connections

18.3.1 Water piping at the chiller shall be arranged so that the machine carries no piping weight and no thermal load, and shall conform to Hydronic PipingHydronic PipingResolves to the current edition.sync/hydronic-piping.

18.3.2 The accessories the chiller manufacturer furnishes at the water connections shall be as indicated in the datasheet.

Water Connection Accessories Furnished with the Chillercheckbox

☑ Flow proving devices at the evaporator and condenser

☐ Thermometer wells at each water connection

☐ Pressure gauge taps at each water connection

☑ Factory-mounted water temperature sensors

☑ Companion flanges or grooved couplings

☐ Victaulic-style adapters

18.3.3 A strainer shall be installed in the water piping upstream of each heat exchanger inlet, with a mesh not coarser than the manufacturer requires, under Hydronic PipingHydronic PipingResolves to the current edition.sync/hydronic-piping.

18.3.4 Isolation valves shall be installed at each water connection so that the machine can be isolated and drained without draining the loop.

18.3.5 The loops shall be cleaned, flushed, and released under Hydronic Cleaning And FlushingHydronic System Cleaning and FlushingResolves to the current edition.sync/hydronic-cleaning-and-flushing before the chiller is placed in service, and the release shall be documented.

18.3.6 Temporary startup strainers shall be removed or their elements replaced before the machine is accepted, and the removal shall be recorded.

NOTE A temporary startup strainer left in service is one of the more common causes of a first-season capacity complaint. It collects construction debris steadily, the resulting pressure drop reduces flow through the evaporator, and nothing in the control system reports it because the machine simply makes less water colder. (18.3.7)

18.4 Relief Vent Piping

18.4.1 Relief device discharge piping shall be installed relief vent routing as indicated on the mechanical plans in accordance with ANSI/ASHRAE 15 and within the equivalent length the submitted relief calculation permits.

18.4.2 Relief vent piping shall be supported independently of the chiller and shall not impose load on the relief device.

18.4.3 Relief vent piping shall be arranged so that condensate and rainwater cannot collect in the line or discharge back onto the device.

18.4.4 The vent termination shall be located so that discharged refrigerant cannot re-enter the building through an opening, an air intake, or a means of egress.

NOTE A vent line that traps water is a vent line with an unknown back pressure. Water standing in a low point has to be lifted before the device can relieve, and the resulting pressure is not in anyone's calculation. (18.4.5)

18.5 Electrical Connections

18.5.1 Field power conductors shall terminate only at the terminations the chiller manufacturer provides, and no field modification shall be made to the unit enclosure without the manufacturer's written acceptance.

18.5.2 Control interlock wiring between the chiller, the pumps, the heat rejection equipment, and the building automation system shall be installed and verified before startup.

18.5.3 Conductor sizing, overcurrent protection, and disconnecting means shall conform to NFPA 70 Articles 430 and 440 and to the minimum circuit ampacity and maximum overcurrent device size on the unit nameplate.

18.5.4 Where a variable-speed drive is remote from the machine, motor cable length shall not exceed the manufacturer's published limit, and cable type, shielding, and grounding shall conform to HVAC Variable Frequency DrivesHVAC Variable Frequency DrivesResolves to the current edition.sync/hvac-variable-frequency-drives.

NOTE Field-drilled holes in the top or sides of a unit control enclosure are the most common cause of an outdoor chiller's control failures, because every one of them is a path for water into an enclosure the listing assumed was sealed. The manufacturer's provided entries are located where the drainage plane accounts for them. (18.5.5)

19 Field Startup and Acceptance

19.1 Pre-Startup Verification

19.1.1 The Contractor shall verify that the chiller nameplate data match the approved submittal for that chiller tag before the machine is energized.

19.1.2 The Contractor shall verify that both loops have been filled, vented, cleaned, flushed, chemically treated, and released for chiller operation by the parties responsible under Hydronic Cleaning And FlushingHydronic System Cleaning and FlushingResolves to the current edition.sync/hydronic-cleaning-and-flushing and HVAC Water TreatmentHVAC Water TreatmentResolves to the current edition.sync/hvac-water-treatment.

19.1.3 The Contractor shall verify that strainers are clean and that flow through each heat exchanger is within the manufacturer's published minimum and maximum.

19.1.4 The Contractor shall verify supply voltage, phase rotation, and phase balance at the unit terminals against the machine's requirements.

19.1.5 The Contractor shall verify that all safety interlocks, flow proving devices, and protective shutdowns function before the compressor is permitted to run.

19.1.6 The Contractor shall verify that the relief devices are installed, that their vent piping is complete, and that any shipping restraint on the machine has been removed.

19.1.7 The Contractor shall record the refrigerant charge added, the oil charge added, and the standing pressures before the first start.

NOTE Voltage imbalance is the pre-start check most often skipped and the one with the most expensive consequence. A few percent of imbalance at the terminals produces a far larger imbalance in the motor currents and a winding temperature rise that shortens insulation life continuously, and it is invisible once the machine is running normally. (19.1.8)

19.2 Manufacturer Startup

19.2.1 The manufacturer's service technician shall perform the initial startup, shall complete the manufacturer's startup checklist, and shall record the readings and setpoints in a signed startup report.

19.2.2 The startup report shall record entering and leaving water temperatures at both heat exchangers, refrigerant pressures and saturation temperatures, oil pressure and temperature, motor current and voltage on each phase, and the resulting approaches at both heat exchangers.

19.2.3 The setpoints left in the controller at the end of startup shall be listed in the startup report, and any deviation from the submitted sequence shall be identified.

NOTE The approaches recorded at startup become the baseline every later measurement is compared against, and they are only usable if the water temperatures, the flows, and the load at which they were taken are recorded alongside them. An approach with no operating condition attached is a number, not a baseline. (19.2.4)

19.3 Functional Performance Testing

19.3.1 The functional performance testing indicated in the datasheet shall be performed after startup and before acceptance.

Functional Performance Testingcheckbox

☑ Capacity and power input verification at a steady load

☑ Verification of the leaving water temperature control at setpoint

☐ Verification of capacity modulation across the operating range

☑ Verification of each protective shutdown by simulation

☑ Verification of the flow proving interlocks by interrupting flow

☐ Verification of automatic restart after a simulated power interruption

☑ Verification of every point at the building automation system

☑ Verification of the plant staging sequence

☐ Verification of the demand limit response

☐ Sound measurement at the locations the acoustic criteria name

19.3.2 Capacity verification shall be performed at a load steady enough for the measurement, and the measured capacity shall be corrected to the design conditions by a method stated in the test procedure.

19.3.3 Where measured performance falls outside the tolerance of ANSI/AHRI 550/590 for the conditions measured, the Contractor shall notify the Engineer of Record and the remedy indicated in the datasheet shall apply.

19.3.4 The Contractor shall coordinate with the balancing agency under Testing Adjusting And BalancingTesting, Adjusting, and Balancing for HVACResolves to the current edition.sync/testing-adjusting-and-balancing to confirm design flow through both heat exchangers before capacity is measured.

NOTE Field capacity verification on a chiller is hard for a reason worth stating plainly: the measurement needs a steady load at or near the design condition, and buildings under construction rarely have one. A test run against a partial load and corrected across a wide extrapolation carries an uncertainty large enough to swallow the tolerance it is being compared against. Where the number has to be defensible, that is the argument for a factory test instead. (19.3.5)

19.4 Owner Training

19.4.1 The manufacturer shall provide training for the Owner's operating personnel for not less than the duration indicated in the datasheet.

Owner Training Durationrange

hours

248162440

19.4.2 Training shall cover the sequence of operation, the controller interface, the alarm codes and their responses, routine maintenance, the water quality limits, the refrigerant handling requirements, and the safety provisions of the machine.

19.4.3 Training shall be delivered after the machine is operating and shall be recorded, and the recording shall be delivered to the Owner.

NOTE Training delivered before startup is training on a machine nobody has seen run, and it is forgotten by the time the building is occupied. Delivering it after the machine is operating lets the operator ask about the alarm that actually occurred rather than about the list in the manual. (19.4.4)

20 Refrigerant Management

20.1 Handling and Recordkeeping

20.1.1 All refrigerant handling shall be performed by technicians certified under 40 CFR Part 82 for the equipment type.

20.1.2 Refrigerant shall not be knowingly vented, and refrigerant removed from the machine shall be recovered into approved containers.

20.1.3 The Contractor shall furnish the refrigerant management documentation indicated in the datasheet.

Refrigerant Management Documentationcheckbox

☑ Refrigerant charge record with quantity, date, and technician certification

☐ Refrigerant purchase and delivery documentation

☑ Recovery record for any refrigerant removed during construction

☑ Leak test record with the method and the sensitivity used

☑ Statement of the refrigerant end-use category claimed under 40 CFR Part 84

☐ Manufacturer leak rate calculation procedure for the machine

20.1.4 The full operating charge shall be marked on the unit nameplate and shall be recorded in the operation and maintenance manual.

NOTE The leak repair obligations of 40 CFR Part 82 apply to appliances above a threshold charge and are expressed as an annual leak rate against the full charge. Recording the charge accurately at handover is what makes those obligations computable, and it is the Owner rather than the Contractor who carries them for the next thirty years. (20.1.5)

21 Delivery, Storage, and Handling

21.1 Shipping Configuration

21.1.1 The shipping configuration shall be as indicated in the datasheet.

Chiller Shipping Configurationselect

Shipped fully assembled and factory charged

Shipped fully assembled with a nitrogen holding charge

Shipped with the compressor and drive separated for rigging

Shipped with the shells separated for rigging and field assembled by the manufacturer

21.1.2 Where the machine is shipped in sections, the manufacturer shall perform the field assembly, the evacuation, and the charging, and shall document each.

21.1.3 The Contractor shall verify the rigging path against the shipping configuration before the machine is released for shipment.

NOTE Shipping split is a rigging decision made months before the lift, and it is irreversible in the wrong direction. A machine shipped assembled that cannot fit through the opening has to be disassembled by someone who did not build it, and the field assembly and evacuation that follow are not covered by anyone's warranty. (21.1.4)

21.2 Protection and Storage

21.2.1 Chillers shall be shipped with every opening closed by the manufacturer's protective covers, and the covers shall remain in place until the connecting piping is made up.

21.2.2 Shipments shall be inspected for damage on arrival, and damage shall be photographed and reported to the manufacturer before the shipment is accepted.

21.2.3 The holding charge pressure shall be measured on arrival and recorded, and a loss of holding pressure shall be reported to the manufacturer before the machine is set.

21.2.4 Storage requirements shall follow the expected storage duration indicated in the datasheet.

Storage Duration Before Startupradio

● Less than three months

○ Three to twelve months

○ More than twelve months

21.2.5 Where storage will exceed three months, the manufacturer's extended storage procedure shall be obtained and followed, and each action taken shall be logged.

21.2.6 Where storage will exceed three months, oil heaters and control panel heaters shall be energized, and where power is unavailable the manufacturer shall be consulted before the machine is stored.

NOTE The holding pressure measured on arrival is the only evidence that the refrigerant circuit is still sealed. A machine that lost its holding charge in transit has an open circuit that has been breathing humid air, and discovering that at startup rather than at delivery moves the cost from the carrier to the project. (21.2.7)

21.3 Rigging and Lifting

21.3.1 Rigging shall use only the lifting points the manufacturer designates, and the manufacturer's rigging instructions shall be present at the point of rigging and reviewed before the lift.

21.3.2 Slings shall not be passed around shells, piping, control panels, or coil surfaces.

21.3.3 The lift shall account for the center of gravity the manufacturer publishes, which on a chiller is rarely at the geometric center of the frame.

NOTE A chiller's mass is concentrated in the shells and the compressor rather than distributed, so its center of gravity sits well off center in at least one axis. A lift rigged symmetrically on a machine that is not tips as it leaves the ground, and the resulting swing is what damages control panels and coil faces. (21.3.4)

22 Warranty

22.1 Warranty Period and Coverage

22.1.1 Each chiller shall be warranted against defects in materials and workmanship for the period indicated in the datasheet.

Chiller Warranty Periodrange

years

1235710

22.1.2 The compressor and its drive shall be warranted for the period indicated in the datasheet, measured from the same commencement date as the chiller warranty.

Compressor and Drive Warranty Periodrange

years

1235710

22.1.3 The warranty period shall begin on the date indicated in the datasheet.

Warranty Commencementradio

● Date of substantial completion

○ Date of beneficial use by the Owner

○ Date of startup

○ Date of delivery to the site

22.1.4 Warranty coverage shall include the items indicated in the datasheet.

Warranty Coveragecheckbox

☑ Replacement parts

☑ On-site labor for repair or replacement

☐ Removal and reinstallation of the machine or its components

☑ Refrigerant lost through a warranted failure

☑ Oil replaced during a warranted repair

☐ Freight both ways on returned components

☐ Annual preventive maintenance visits

☐ Annual oil and refrigerant analysis

☐ Next business day on-site response

22.1.5 Where the datasheet indicates no compressor and drive warranty period, the compressor and drive shall carry the same period as the chiller.

NOTE Refrigerant coverage is worth naming separately because it is the exclusion most often discovered after a failure. A large centrifugal machine can hold well over a thousand pounds of a refrigerant that costs more per pound than the labor to install it, and a warranty that replaces the failed component while leaving the Owner to buy back the charge covers a fraction of the actual loss. (22.1.6)

22.2 Repair and Re-Warranty

22.2.1 A component repaired or replaced under warranty shall carry a new warranty running for the full original period from the date the repair is completed, or for the remainder of the original period, whichever ends later.

22.2.2 The manufacturer shall bear the cost of collateral damage caused by a warranted failure or by the warranty repair itself, including damage to the shells, the drive, the controls, and directly connected piping.

22.2.3 Where the Engineer of Record and the manufacturer disagree whether a failure is covered, the initial determination shall be made by the Engineer of Record.

NOTE A re-warranty written as the remainder of the original term shrinks toward nothing as the term runs out, so a compressor replaced in the eleventh month of a twelve-month warranty would carry one month of coverage on a component that took eleven months to fail. Restarting the full term from the repair date removes that. (22.2.4)

22.3 Warranty Exclusions

22.3.1 Warranty coverage shall not extend to damage caused by installation contrary to the manufacturer's published instructions.

22.3.2 Warranty coverage shall not extend to damage caused by operation outside the flow, temperature, or pressure limits stated in the submittal.

22.3.3 Warranty coverage shall not extend to damage caused by water chemistry outside the manufacturer's published limits, provided those limits were stated in the submittal.

22.3.4 Warranty coverage shall not extend to damage caused by loss of electrical supply quality, including sustained voltage imbalance, single phasing, or supply harmonic distortion originating outside the equipment furnished.

22.3.5 Warranty coverage shall not extend to damage caused by service conditions materially different from those stated at the time of selection.

NOTE Each exclusion here is conditioned on the manufacturer having published the limit it relies on. An exclusion for water chemistry that surfaces only after a tube failure, against a limit the Owner was never given, is not enforceable in any useful sense, and requiring the limits in the submittal is what makes the exclusion fair in both directions. (22.3.6)

23 Spare Parts

23.1 Spare Parts Furnished

23.1.1 The spare parts indicated in the datasheet shall be furnished at substantial completion.

Spare Parts Furnishedcheckbox

☑ One set of oil filters for each chiller model installed

☑ One set of refrigerant filter driers for each chiller model installed

☐ One oil charge for each chiller model installed

☑ One set of gaskets for the waterboxes and access covers

☑ One set of pressure and temperature sensors of each type used

☐ One controller display module

☐ One controller processor module

☐ One condenser fan motor for each air-cooled chiller model installed

☐ One set of tube plugs and an installation tool

☐ A supply of the refrigerant furnished, in the quantity indicated

23.1.2 Spare parts shall be packaged for long-term storage and labeled with the chiller tags they serve, the model, and the manufacturer's part number.

23.1.3 Spare parts shall be delivered to the Owner and receipted, and the receipt shall be included in the closeout submittal.

NOTE Tube plugs earn their place on the list out of proportion to their cost. A single leaking tube takes a chiller out of service completely, and plugging it restores the machine within hours at a capacity penalty of a fraction of a percent, where waiting to retube it can mean a season without cooling. (23.1.4)

23.2 Maintenance Documentation and Tools

23.2.1 The documentation and tools indicated in the datasheet shall be furnished with the chillers.

Maintenance Documentation and Toolscheckbox

☑ Installation, operation, and maintenance manual for each model furnished

☑ Preventive maintenance schedule with intervals

☑ Published water quality limits for both loops

☑ Alarm and fault code list with the diagnostic response for each

☑ Wiring diagrams as built

☐ Controller programming documentation and the sequence as programmed

☐ Model-specific service tools such as tube cleaning brushes and puller fixtures

☑ Spare parts ordering guide with manufacturer part numbers

☐ Certified dimensional drawing for each model furnished

23.2.2 The startup report, with the commissioned approaches and operating conditions recorded on it, shall be placed in the operation and maintenance manual.

NOTE That single page answers most future questions about the machine. Every judgment an operator or a service technician later makes about whether a chiller has degraded is a comparison against the day it was known to be right, and without the commissioned baseline the comparison is against a catalog rating taken at conditions the building never sees. (23.2.3)