1 Scope
NOTE This standard governs the furnishing, factory testing, field installation, and commissioning of commercial refrigeration equipment that maintains a controlled cold environment for food, pharmaceutical, or laboratory product. (1.1)
NOTE Covered equipment includes the following categories, each defined by its enclosure type and the integration of its refrigeration system: (1.2)
- Walk-in coolers and walk-in freezers assembled from prefabricated modular insulated panels, with floor or floorless configurations.
- Self-contained packaged walk-in units in which the refrigeration system is integral to the enclosure (monobloc rooftop or wall-mount).
- Reach-in refrigerators and freezers, including single- and multi-section solid-door and glass-door cabinets.
- Refrigerated display cases, including vertical open multi-deck and horizontal coffin/chest types.
- Under-counter and prep-table refrigeration with stainless work surfaces.
- Pharmaceutical and laboratory refrigerators and freezers requiring temperature stability and alarm monitoring.
NOTE The refrigeration system furnished under this standard comprises the condensing unit, evaporator or unit cooler, expansion device, refrigerant charge, and controls, where these are integral to the equipment or where a remote condensing unit serves a single self-contained enclosure within the same building section. (1.3)
NOTE Where a walk-in or display system uses a remote condensing unit furnished and piped as separate mechanical equipment, that condensing unit is specified under
Condensing Units and the interconnecting refrigerant piping under
Refrigerant Piping; this standard covers the enclosure, evaporator, doors, and controls and coordinates with those scopes.
(1.4) NOTE This standard applies to maintained interior temperatures from approximately +55°F down to −20°F for coolers and −40°F for freezers, in new construction and in like-for-like equipment replacements. (1.5)
2 Referenced Standards
2.1Equipment, materials, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
2.2Where referenced standards conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
| Standard |
Title |
| ASHRAE 15-2022 |
Safety Standard for Refrigeration Systems (incl. addendum q) |
| ASHRAE 34-2022 |
Designation and Safety Classification of Refrigerants |
| AHRI 1250 (I-P)-2020 |
Performance Rating of Walk-In Coolers and Freezers |
| NSF/ANSI 7-2022 |
Commercial Refrigerators and Freezers |
| UL 60335-2-89 |
Commercial Refrigerating Appliances with Incorporated or Remote Refrigerant Unit or Motor-Compressor |
| UL 471 |
Commercial Refrigerators and Freezers (superseded by UL 60335-2-89, 2024-09-29) |
| UL 207 |
Refrigerant-Containing Components and Accessories, Nonelectrical |
| 10 CFR Part 431, Subpart R |
DOE Energy Conservation Standards for Walk-In Coolers and Walk-In Freezers |
| NFPA 70 |
National Electrical Code (Article 440) |
| ENERGY STAR Commercial Refrigerators and Freezers V4 |
Program Requirements for Commercial Refrigerators and Freezers |
NOTE UL 471 was officially superseded by UL 60335-2-89 on 2024-09-29; equipment newly certified shall reference UL 60335-2-89, while legacy submittals listing UL 471 remain acceptable for inventory certified before that date. (2.3)
3 Submittals
3.1 Action Submittals
3.1.1The Contractor shall submit the following action submittals for review before fabrication or ordering:
- Product data for each refrigeration unit, including capacity, electrical characteristics, refrigerant type and charge, and rated ambient.
- AHRI-certified AWEF rating data per AHRI 1250 demonstrating compliance with 10 CFR Part 431, Subpart R for each walk-in system.
- Shop drawings for walk-in enclosures showing panel layout, dimensions, door locations and swings, floor type, and structural loading.
- Refrigerant designation and safety classification per ASHRAE 34, with charge quantity and the ASHRAE 15 charge-limit calculation for the served space.
- NSF/ANSI 7 certification listing for each unit in food-service or healthcare applications.
- Wiring diagrams identifying field-installed connections, disconnects, and control interfaces.
- Control sequence and alarm schedule, including high-temperature and power-failure alarm outputs.
☑ Product data (capacity, electrical, refrigerant, ambient)
☑ AHRI-certified AWEF data per AHRI 1250
☐ Walk-in enclosure shop drawings
☑ Refrigerant designation and ASHRAE 15 charge calculation
☐ NSF/ANSI 7 certification listing
☑ Wiring diagrams
☐ Control sequence and alarm schedule
3.2 Closeout Submittals
3.2.1The Contractor shall submit the following closeout submittals before Substantial Completion:
- Operation and maintenance manuals for each unit, including defrost and control programming.
- Manufacturer's written warranty, including any extended compressor warranty.
- Commissioning report documenting pull-down performance, setpoint verification, and alarm testing.
- Refrigerant charge record listing type, quantity, and date of charging per unit.
- As-built control points list and BMS/EMS integration map where applicable.
☑ Operation and maintenance manuals
☑ Manufacturer's written warranty
☑ Commissioning report
☑ Refrigerant charge record
☐ As-built control points list
3.3.1The Contractor shall submit the following informational submittals where the listed condition applies:
- Structural loading data for walk-in units exceeding the design floor capacity, for review by the Structural Engineer of Record.
- Refrigerant leak-detection and machinery-room ventilation provisions where ASHRAE 15 thresholds are exceeded.
- AHJ confirmation of A2L refrigerant code adoption where A2L equipment is proposed.
☑ Structural loading data
☐ Leak-detection / ventilation provisions (ASHRAE 15)
☐ AHJ A2L code-adoption confirmation
4 Quality Assurance
4.1Each unit furnished for a food-service or healthcare application shall be certified to NSF/ANSI 7 and bear the certifying agency's mark.
4.2Each electrically operated unit shall be listed to UL 60335-2-89 or, for legacy inventory certified before 2024-09-29, to UL 471.
4.3Nonelectrical refrigerant-containing components, including receivers, filter-driers, and service valves, shall comply with UL 207.
4.4Walk-in refrigeration systems shall carry an AHRI 1250 certification confirming the rated AWEF used to demonstrate DOE compliance.
NOTE NSF/ANSI 7 certification establishes food-safety construction and sanitation requirements; it does not cover pharmaceutical or laboratory cold storage, which instead cites USP Chapter 1079 or the equivalent program identified by the Owner. (4.5)
NOTE Health-department inspection of food-service installations will reject units lacking NSF/ANSI 7 certification; the certification basis for laboratory applications should be confirmed early, because the food-safety mark and the pharmaceutical-grade requirement are not interchangeable. (4.6)
4.7The manufacturer shall be regularly engaged in the production of commercial refrigeration equipment of the type specified and shall furnish field start-up by a factory-authorized technician.
● Required (food service / healthcare)
○ Not required (non-food storage)
○ Alternate program (lab/pharmaceutical per USP 1079)
5 Refrigerant and Regulatory Compliance
NOTE The refrigerant phasedown under the AIM Act and EPA SNAP program drives refrigerant selection for new equipment. The AIM Act prohibits the manufacture and sale of new remote refrigeration systems using high-GWP HFCs, including R-404A, in retail food and cold-storage applications after December 31, 2025. A2L refrigerants such as R-454A and R-454C are the likely successor default; R-448A and R-449A remain permitted through the transitional period. (5.1)
NOTE Because equipment ordered between 2025 and 2028 may ship with transitional HFC blends while later equipment uses A2Ls, the specification should state refrigerant-class acceptance criteria rather than naming a single refrigerant designator wherever possible. (5.2)
5.3Refrigerant shall be a non-ozone-depleting blend approved under the EPA SNAP program for the equipment's end use and shall comply with the AIM Act HFC phasedown schedule in effect at the time of manufacture.
5.4R-404A and R-407C shall not be furnished in new remote refrigeration systems for retail food or cold-storage applications.
5.5Each refrigerant shall be classified per ASHRAE 34, and the refrigerant charge shall comply with the charge limits and refrigerant concentration limit (RCL) of ASHRAE 15-2022 for the served occupancy.
5.6Where an A2L refrigerant is furnished, the equipment shall comply with the A2L provisions of ASHRAE 15-2022 addendum q and UL 60335-2-89, including any required leak detection and mitigation.
NOTE A2L equipment shall not be furnished until the Authority Having Jurisdiction has adopted the mechanical code edition referencing ASHRAE 15-2022; some jurisdictions lag on A2L adoption and will reject the submittal. (5.7)
○ A2L (R-454A / R-454C) preferred
○ A1 transitional blend (R-448A / R-449A) acceptable
● Either A2L or A1 transitional, Contractor's option
6 Energy Efficiency
NOTE Federal minimum efficiency for walk-in coolers and freezers is set by the Annual Walk-in Energy Factor (AWEF) under 10 CFR Part 431, Subpart R. DOE amended these standards in December 2024, with refrigeration-system compliance required by December 31, 2028 and door-standard compliance required by December 23, 2027. AWEF minimums vary by equipment class. (6.1)
NOTE Manufacturers may offer legacy inventory that does not meet the amended efficiency classes; AWEF compliance must be confirmed at the submittal stage against the class-specific thresholds in 10 CFR Part 431, Subpart R, not assumed. (6.2)
6.3Each walk-in refrigeration system shall meet or exceed the AWEF minimum for its equipment class under 10 CFR Part 431, Subpart R in effect at the time of procurement.
6.4The Contractor shall submit AHRI-certified AWEF data with the equipment submittal, and rated values that do not meet the applicable DOE class minimum shall be rejected.
6.5Reach-in and display equipment specified to ENERGY STAR shall comply with the daily-energy-consumption limits of the ENERGY STAR Commercial Refrigerators and Freezers V4 specification.
6.6Walk-in panel insulation shall meet the minimum nominal R-value for its service class, achieved with CFC-free foam-core panels.
R-32 (4 in. cooler panel)
R-40 (5 in. freezer panel)
R-48 (6 in. heavy-use freezer panel)
NOTE Walk-in coolers shall maintain an interior temperature within the specified setpoint band; NSF/ANSI 7 limits food-safety cooler temperature to a maximum of +40°F. (7.1)
NOTE Walk-in freezers shall maintain the specified frozen-storage temperature; general frozen food is held near −10°F, while ice cream and hard-freeze product require −20°F. (7.2)
7.3The maintained interior cooler temperature shall not exceed +40°F for any food-storage application.
7.4Refrigeration capacity shall account for the full design load, including transmission gain through the enclosure, door and infiltration load, interior lighting, evaporator-fan and defrost heat, and product pull-down load.
7.5Condensing units serving the equipment shall be rated for the design ambient at their installed location, with 95°F dry-bulb assumed unless a higher value is specified for desert climates.
NOTE Condensing-unit capacity selected on the cooler-interior load alone, without adding door-infiltration, lighting, and product pull-down loads, is a recurring RFI and short-cycling source; the full design load is the basis of selection. (7.6)
NOTE Self-contained reach-in units shall be rated for the ambient temperature at their installed location; most are rated only for 75°F to 95°F ambient, which commercial kitchens routinely exceed without supplemental cooling. (7.7)
8 Equipment Configuration
NOTE The equipment type, temperature service, and system configuration shall be selected for the application. The decision among self-contained and remote configurations determines whether a separate condensing-unit and refrigerant-piping scope applies. (8.1)
NOTE Self-contained equipment incorporates its refrigeration system within the unit; a remote system pairs the evaporator furnished here with a separately specified condensing unit under
Condensing Units and piping under
Refrigerant Piping.
(8.2) 8.3Each unit shall be furnished in the temperature service, enclosure type, and system configuration scheduled, and shall not substitute a self-contained system where a remote condensing unit is required for noise, heat-rejection, or maintenance-access reasons.
Walk-in cooler (modular panel)
Walk-in freezer (modular panel)
Combination cooler-freezer walk-in
Reach-in refrigerator
Reach-in freezer
Refrigerated display case (multi-deck)
Refrigerated display case (coffin/chest)
Under-counter / prep-table refrigerator
Pharmaceutical / laboratory refrigerator
● Cooler (+35°F to +55°F)
○ Freezer (−10°F to −20°F)
○ Blast chiller
○ Specialty (pharmaceutical / lab, +34°F to +46°F)
○ Self-contained packaged
● Remote condensing unit with separate unit cooler
Indoor, remote from food area
Outdoor rooftop
Outdoor grade-level
9 Walk-In Panel Construction
NOTE Modular walk-in enclosures are built from prefabricated foam-core panels that lock together with cam-action fasteners to form a continuous insulated envelope. Panel facing, foam core, thickness, and floor type are selected for the service temperature and sanitation requirement. (9.1)
9.2Walk-in panels shall be prefabricated foam-core panels with a CFC-free polyurethane or polyisocyanurate core of nominal 28 to 32 lb/ft³ density.
9.3Cooler panels shall be a minimum nominal 4 in. thick; standard freezer panels shall be a minimum nominal 5 in. thick; heavy-use freezer panels shall be a minimum nominal 6 in. thick.
9.4Panels shall lock together with concealed cam-action locking devices that draw the joint tight and compress a continuous gasket at each panel edge.
9.5Interior facing in food-service and healthcare applications shall be stainless steel or a smooth, cleanable, NSF/ANSI 7-compliant finish; non-food applications may use galvanized steel or aluminum facing.
9.6Exterior facing shall be galvanized steel, stainless steel, or aluminum as scheduled, with a finish suited to the installed environment.
NOTE Walk-in freezers without an insulated floor panel allow frost to propagate into the slab and cause frost heave; a floor panel is therefore standard on freezers. (9.7)
9.8Coolers installed over unconditioned or non-slab space shall be furnished with a floor panel; coolers on a conditioned interior slab may be floorless with a thermal break and screed at the perimeter.
9.9Walk-in freezers shall be furnished with an insulated floor panel rated for the imposed traffic and product load.
● Polyurethane foam (CFC-free)
○ Polyisocyanurate foam (CFC-free)
4 (cooler)
5 (freezer standard)
6 (freezer heavy-use)
● Stainless steel
○ Galvanized steel
○ Aluminum
● Galvanized steel
○ Stainless steel
○ Aluminum
● Insulated floor panel
○ Floorless with thermal break and screed
NOTE The walk-in footprint and product load shall be coordinated with the structural slab; loaded prefabricated units can exceed 300 psf, and slab capacity must be verified before equipment selection. (9.10)
9.11Walk-in unit weight and imposed floor loading shall be coordinated with the Structural Engineer of Record, and the supporting slab shall be confirmed adequate before the unit is ordered.
10 Doors and Hardware
NOTE Doors are the highest-infiltration and highest-maintenance element of a walk-in enclosure. Freezer doors require heat at the frame and gasket to prevent the door from freezing shut and to keep the seal intact. (10.1)
10.2Doors shall be insulated to match the panel service class and shall be furnished with a cam-lift or spring-assisted hinge that self-closes the door.
10.3Each door shall have a continuous magnetic or compression gasket that seals against the frame on all four edges.
10.4Walk-in freezer doors shall be furnished with frame-mounted anti-sweat (perimeter) heaters and a heated gasket to prevent ice buildup and seal failure.
NOTE Anti-sweat heaters and heated door frames are sometimes value-engineered out of walk-in freezer doors, which causes ice buildup, gasket failure, and premature door damage; they should be retained on every freezer door. (10.5)
10.6Each walk-in door shall be furnished with an interior safety release that allows the door to be opened from inside even when latched.
10.7Glass reach-in and display doors shall be furnished with anti-condensate (anti-sweat) heaters or low-emissivity glazing appropriate to the cabinet service temperature.
10.8Door types and any strip-curtain assemblies shall be furnished as scheduled.
Solid insulated hinged
Glass reach-in door (display)
Sliding door
Strip curtain (supplementary)
● Heated frame and gasket (freezer)
○ Unheated (cooler)
11 Refrigeration System Components
NOTE The refrigeration system comprises the condensing unit, the evaporator or unit cooler inside the enclosure, the expansion device, and the controls that coordinate them. Defrost method is selected for the service temperature and cycling frequency. (11.1)
11.2Evaporators and unit coolers shall be rated per AHRI 1250 at the applicable saturated suction temperature: +25°F for coolers and −20°F for freezers, with condensing temperature of 100°F for coolers and 90°F for freezers.
11.3The expansion device shall be a thermostatic or electronic expansion valve sized for the evaporator load and the selected refrigerant.
11.4Each refrigeration circuit shall be furnished with a filter-drier, sight glass with moisture indicator, and service access valves complying with UL 207.
11.5Coolers shall use off-cycle (air) defrost where the evaporator operates above freezing; freezers shall use electric resistance or hot-gas defrost.
NOTE Off-cycle defrost relies on above-freezing coil temperature to melt frost during the compressor-off cycle and applies only to coolers; freezers require an active defrost heat source. (11.6)
11.7Electric defrost heaters shall be sized per the manufacturer for the coil circuit, typically 750 to 3,000 W per circuit, with a drain-line heater where condensate can refreeze.
11.8Hot-gas defrost shall be provided for high-frequency-cycle freezers where electric defrost would impose excessive runtime or energy use.
11.9Condensate from each evaporator shall be drained to an approved point, and freezer condensate drain lines shall be heat-traced to prevent refreezing within the cold space.
Off-cycle (air) defrost
Electric resistance defrost
Hot-gas defrost
● Thermostatic expansion valve (TXV)
○ Electronic expansion valve (EEV)
12 Controls and Monitoring
NOTE Temperature control ranges from a mechanical thermostat on a small reach-in to a networked controller integrated with a building management or energy management system. Food-service, healthcare, and pharmaceutical applications add continuous monitoring and alarm requirements for HACCP and product-safety compliance. (12.1)
12.2Each unit shall be furnished with a temperature controller appropriate to the application: mechanical thermostat, electronic controller, or BMS/EMS-integrated controller as scheduled.
12.3Food-service, healthcare, and pharmaceutical units shall be furnished with continuous temperature monitoring and remote alarm outputs for high-temperature and power-failure conditions.
NOTE HACCP-compliant monitoring and alarm outputs are not included in base equipment unless specified; food-service, healthcare, and pharmaceutical projects should require them explicitly to avoid an omission at commissioning. (12.4)
12.5Alarm contacts shall be field-wired to the building management system or to a stand-alone monitor, and a HACCP temperature log connection shall be provided where required.
12.6Electronic and networked controllers shall provide an adjustable setpoint, a defrost schedule, and a digital temperature display readable without opening the door.
Mechanical thermostat
Electronic temperature controller
BMS/EMS-integrated controller
☑ High-temperature alarm
☑ Power-failure alarm
☐ Remote alarm output to BMS/EMS
☐ HACCP temperature log connection
13 Electrical
NOTE Refrigeration equipment electrical work is governed by NFPA 70, with Article 440 covering hermetic refrigerant motor-compressors and the sizing of overcurrent protection and disconnects. (13.1)
13.2Each unit shall be furnished with electrical characteristics matching the service provided: self-contained reach-ins at 115 V/1Φ/60 Hz or 208–230 V/1Φ/60 Hz, and walk-in condensing units at 208–230 V/3Φ/60 Hz or 460 V/3Φ/60 Hz.
13.3Overcurrent protection, conductor sizing, and disconnect means shall comply with NFPA 70 Article 440 for hermetic refrigerant motor-compressors.
13.4A disconnecting means shall be provided within sight of each condensing unit and each separately powered unit cooler as required by NFPA 70.
13.5Equipment grounding shall be provided for each unit in accordance with NFPA 70.
115 V / 1Φ / 60 Hz
208–230 V / 1Φ / 60 Hz
208–230 V / 1Φ / 60 Hz
208–230 V / 3Φ / 60 Hz
460 V / 3Φ / 60 Hz
14 Testing
14.1The refrigerant side shall be leak-tested per ASHRAE 15 at the maximum working pressure before charging.
14.2Each electrically operated unit shall pass the electrical-safety test required by UL 60335-2-89 as part of its factory certification.
14.3Each walk-in refrigeration system shall demonstrate temperature pull-down performance per the rating method of AHRI 1250.
14.4Factory acceptance shall confirm that the unit holds its rated capacity and setpoint before shipment, and the test record shall accompany the closeout submittals.
☑ ASHRAE 15 refrigerant-side leak test
☑ UL 60335-2-89 electrical-safety test
☑ AHRI 1250 pull-down performance test
15 Installation
15.1Walk-in panels shall be assembled on a level, structurally adequate base in the sequence and orientation shown on the approved shop drawings, with each cam lock fully engaged and each joint gasket compressed.
15.2The enclosure shall be sealed at all panel joints, floor-to-wall transitions, and penetrations to maintain a continuous vapor and thermal barrier.
15.3Condensing units, evaporators, and refrigerant connections shall be installed per the manufacturer's instructions, with refrigerant piping for remote systems installed under Refrigerant Piping. 15.4Condensate and defrost drains shall be installed with the required slope and, for freezers, with heat trace, and shall discharge to an approved indirect-waste connection.
15.5Equipment shall be installed level, plumb, and with the manufacturer's required service clearances at the condensing unit, evaporator, and electrical disconnects.
15.6Penetrations through walk-in panels for piping, wiring, and drains shall be sealed and, where they breach a freezer envelope, insulated to prevent condensation and frost.
16 Commissioning
16.1Commissioning shall verify that each unit holds its interior setpoint within ±2°F over a continuous 24-hour period before acceptance.
16.2The Contractor shall verify the door gasket seal on every door and adjust hinges and closers so each door self-closes and seals.
16.3High-temperature and power-failure alarm contacts shall be tested and confirmed to report to the building management system or stand-alone monitor.
16.4Where HACCP logging is required, the temperature-log connection shall be commissioned and confirmed to record interior temperature at the required interval.
16.5The refrigerant charge shall be confirmed against the manufacturer's charge data and recorded by type, quantity, and date.
17 Delivery, Storage, and Handling
17.1Equipment and panels shall be delivered in the manufacturer's protective packaging and stored under cover, protected from weather, impact, and construction dust until installation.
17.2Panels shall be stored flat and supported to prevent facing distortion, and stainless facings shall retain their protective film until the enclosure is cleaned for service.
17.3Self-contained units with a factory refrigerant charge shall be kept upright during transport and storage and shall sit for the manufacturer's required settling period before start-up.
18 Warranty
18.1The manufacturer shall warrant each unit against defects in materials and workmanship for a minimum of one year from Substantial Completion.
18.2The hermetic compressor in each refrigeration system shall carry an extended warranty of not less than five years from Substantial Completion.
19 Spare Parts
19.1The Contractor shall furnish one complete set of door gaskets for each walk-in and reach-in door type installed.
19.2The Contractor shall furnish spare evaporator-fan motors and defrost heaters in the quantity scheduled, or one of each type where no quantity is scheduled.
19.3The Contractor shall furnish one set of filter-drier cores and any unit-specific fuses for each refrigeration circuit.
☑ Door gasket set (per door type)
☐ Spare evaporator-fan motor
☐ Spare defrost heater
☑ Filter-drier cores
☐ Control fuses