SynC · Topic
These are the standards in the SynC Standards library that cover HVAC. Each one is a complete, plain-language specification: the scope it applies to, the requirements that govern it, and a structured equipment datasheet listing the values a project has to decide — ratings, materials, setpoints, and the standards each is verified against. All of it is free to read without an account and published under CC BY-SA 4.0.
A standard usually carries several topics, so most of the entries below also appear under neighbouring subjects. The topics each one carries are listed on its own page.
Central station air handling units that condition air and deliver it through a field-installed duct distribution system, whether factory-assembled in shipping sections or field-erected from components. Covers indoor and outdoor units, constant-volume and variable-air-volume systems, single-zone and multiple-zone arrangements, mixed-air units and dedicated outdoor air units, and units serving commercial, institutional, industrial, healthcare, and laboratory occupancies.
Factory-fabricated air terminal units that meter primary air from a central air system into an individual thermal zone in commercial, institutional, healthcare, and industrial buildings. Covers single-duct, dual-duct, and bypass metering arrangements; variable-volume and constant-volume airflow control; pressure-independent and pressure-dependent control basis; parallel and series fan sections; hot water, steam, and electric reheat with their valves, actuators, and safety devices; casing construction and acoustic treatment; primary damper and actuator; primary airflow sensing; radiated and discharge sound; the zone controller, zone sensor, and building automation interface; factory testing; installation; and field airflow, functional, and acoustic verification.
Gas-fired and oil-fired hydronic (hot water) and low-pressure steam heating boilers for commercial, institutional, and industrial HVAC space-heating service. Covers condensing and non-condensing units, fire-tube and water-tube configurations, single and modular (multiple-boiler) plants, and packaged factory-assembled units from approximately 300 MBH input through the upper limit of low-pressure heating boiler service (15 psig steam; 160 psig and 250°F hot water). Addresses natural gas, propane, No. 2 fuel oil, and dual-fuel firing, with modulating and staged combustion controls and building automation system integration.
Factory-assembled vapor-compression liquid chillers that produce chilled water or a chilled water-glycol solution for building cooling and for process cooling in the same temperature range. Covers centrifugal, screw, scroll, and reciprocating compressor machines across the full commercial and institutional capacity range, with water-cooled, air-cooled, evaporatively cooled, and remote-condenser heat rejection. Addresses the compressor and its drive, the evaporator and condenser pressure vessels, the refrigerant circuit and its safety devices, the unit controller and its interface to the building automation system, the integral power and starting equipment, factory and field acceptance testing, and the setting, clearance, and connection items that decide whether the installed machine reaches its certified rating.
Open-circuit and closed-circuit (fluid cooler) evaporative heat-rejection equipment for HVAC condenser water systems serving water-cooled chillers, water-source heat pump loops, and process cooling in commercial, institutional, and industrial buildings. Covers field-erected and factory-assembled (packaged) towers; induced-draft and forced-draft configurations; counterflow and crossflow arrangements; galvanized steel, stainless steel, and fiberglass (FRP/HDPE) construction; axial and centrifugal fans with constant-speed, two-speed, and variable-speed drives. Applicable from small rooftop packaged towers through large multi-cell field-erected installations.
Packaged dedicated outdoor air systems (DOAS) that condition 100% outdoor air to satisfy the building's ventilation requirement independently of the spaces' sensible cooling and heating. Covers indoor and outdoor/rooftop units, the air-to-air energy recovery section (enthalpy wheel, fixed-plate, heat-pipe, or runaround loop), the deep-cooling and dehumidification section (integrated DX, air-source or water-source heat pump, or chilled water), the reheat method that controls leaving dewpoint and supply air temperature (hot-gas reheat, modulating reheat, wraparound heat pipe, or dehumidification wheel), the heating source, filtration, fans, casing, and the controls integration that coordinates the DOAS with the parallel sensible system it serves. Applicable to DOAS paired with variable refrigerant flow, fan coils, chilled beams, water-source heat pumps, or sensible-only rooftop units, in commercial, institutional, multifamily, and light-industrial buildings.
Room-side air distribution devices that terminate a ducted or plenum air system at the boundary of an occupied space - supply outlets (square and rectangular face, round face, linear slot, swirl, displacement, light-fixture-integrated), return and exhaust inlets, and transfer openings, together with the frames, cores, integral dampers, and finishes furnished as part of the device. Covers the performance criteria that govern occupant comfort and acoustic acceptability (throw at 50, 100, and 150 fpm terminal velocities, ADPI, occupied-zone air speed, occupied-space sound level), device materials for dry, wet, and corrosive service, exposed finishes, security and anti-ligature construction, installation and support, and field balancing and verification. Applies to new construction and to renovation where devices are connected to a distribution system.
Metal and flexible ductwork for low-pressure, medium-pressure, and high-pressure HVAC air distribution systems in commercial, institutional, and industrial buildings. Covers rectangular, round, flat-oval, and flexible duct; pressure and seal classifications; gauge and reinforcement; fittings and turning vanes; duct liner and external insulation; sealants; fire and smoke dampers; access doors; hangers and supports; leakage testing; and field verification. Applies to new construction and major renovation of supply, return, exhaust, and outside-air distribution systems.
General-purpose, field- or factory-installed air-moving equipment serving commercial, institutional, and light-industrial HVAC systems. Covers centrifugal fans (housed and plenum/plug type), axial fans (vaneaxial, tubeaxial, and propeller), inline (cabinet and tubular) fans, utility/SWSI exhaust fans, roof- and wall-mounted power ventilators (upblast and downblast), ceiling-mounted exhaust fans, and dedicated kitchen grease-exhaust fans. Addresses aerodynamic and sound rating and certification (AMCA 210 / 300 / 211 / 311), Fan Energy Index compliance under ASHRAE 90.1 (AMCA 208), AMCA construction class and drive arrangement, direct-drive and belt-drive selection, induction and electronically commutated (EC) motors, bearings, materials and finishes, spark-resistant construction for hazardous exhaust (AMCA 99), accessories, vibration isolation, and the electrical and controls interface to variable-frequency drives and the building automation system.
Rotodynamic (centrifugal) pumps that circulate water and water-glycol solutions for building heating, cooling, and heat-rejection service. Covers closed-loop heating hot water and chilled water pumps, open-loop condenser water pumps serving cooling towers and fluid coolers, condenser loops serving water-source heat pumps, and the vertical turbine pumps used where the supply level sits below the pump. Addresses the pump end, the driving motor, the baseplate or frame, the coupling, shaft sealing, vibration isolation, factory and field acceptance testing, and the coordination items that decide whether the installed pump reaches its certified curve.
Separately procured pulse width modulated variable frequency drives rated 600 V and below, controlling three-phase AC induction motors on HVAC air and hydronic equipment — supply, return, and exhaust fans, chilled water, condenser water, and hot water pumps, and cooling tower fans. Covers drive ratings, enclosure and cooling selection, harmonic performance, bypass and disconnecting means, motor and cable compatibility, protective functions, building automation integration, testing, and installation for drives in mechanical rooms, electrical rooms, penthouses, and outdoor locations.
The ongoing chemical and physical water treatment program for HVAC water systems in commercial, institutional, and industrial buildings. Covers closed hydronic loops (heating hot water, chilled water, dual-temperature, water-source and ground-source heat pump loops, and inhibited-glycol loops), open recirculating condenser water systems served by cooling towers and evaporative condensers, and steam and condensate systems at or below 150 psig. Addresses make-up water characterization, corrosion and scale inhibitor chemistry, biocide programs, cycles of concentration and bleed control, chemical feed and controller equipment, side-stream filtration, sample ports and routine monitoring, corrosion coupon reading, the Legionella risk-management documentation required under ANSI/ASHRAE 188, the service contract that sustains the program, and seasonal lay-up.
Closed-loop hydronic distribution piping for heating hot water (HHW), chilled water (CHW), dual-temperature water (DTW), and condenser water (CW) in commercial, institutional, and industrial buildings, within the ASME B31.9 building-services envelope (up to 160 psig and 250°F). Covers pipe material and wall selection by service and size band, joining methods, fittings and flanges, dissimilar-metal isolation, delivery and storage, piping installation and routing discipline, the interfaces to supports, expansion compensation, valves, specialties, insulation, identification, and system cleaning, and the structural pressure test that proves the installed system.
Stationary exterior and interior louvers and the full range of air-control and life-safety dampers in commercial, institutional, and light-industrial buildings. Covers drainable-blade, storm-resistant (wind-driven-rain), sand-trap, acoustic, combination louver/damper, and penthouse/gooseneck louvers selected by free area and water-penetration class at the design intake velocity; air-control dampers (parallel- and opposed-blade) selected by AMCA 500-D leakage class; backdraft, gravity, and pressure-relief dampers; and the life-safety dampers required at rated barriers — fire dampers (UL 555), smoke dampers (UL 555S), combination fire/smoke dampers, and ceiling radiation dampers (UL 555C) — together with actuators, fusible and resettable links, sleeves, retaining angles, access, and the firestopping interface. Includes hurricane-zone (AMCA 540 / 550) and Florida/High-Velocity-Hurricane-Zone louver requirements and the AMCA Certified Ratings Program basis for ratings.
Field-applied thermal insulation for mechanical piping, ductwork, and equipment in commercial, institutional, and light-industrial buildings. Covers insulation of heating hot water, steam, steam condensate, and other hot service piping; chilled water, dual-temperature, and other below-ambient service piping that requires a continuous vapor barrier; HVAC supply, return, outside-air, and exhaust ductwork (concealed and exposed, indoor and outdoor); and mechanical equipment such as tanks, breechings, pumps, and heat exchangers. Includes selection of insulation material by service (mineral or glass fiber, closed-cell elastomeric, rigid cellular phenolic, cellular glass, and calcium silicate for high temperature), insulation thickness by the adopted edition of ASHRAE 90.1, jacketing and vapor retarders (all-service jacket indoors, PVC fitting covers, metal jacket outdoors and in mechanical rooms), insulated pipe supports and protection shields, penetration coordination, and the condensation-control provisions that govern cold-service work.
Factory-assembled, self-contained packaged units with an integral direct-expansion refrigeration circuit, set on a roof curb and serving a field-installed duct distribution system. Covers cooling-only, gas-fired, electric resistance, hydronic, and reverse-cycle heat pump heating configurations; constant-volume, multi-speed, and variable-air-volume supply fans; air-side economizers, powered relief, minimum outdoor air control, demand-controlled ventilation, and integral exhaust air energy recovery; the cabinet, filtration, drain pan, and roof curb; the refrigerant, its safety group, and the detection and mitigation provisions that go with mildly flammable refrigerants; unit-mounted controls and their interface to the building automation system; and the setting, connection, startup, and balancing of the installed unit.
Field-installed refrigerant piping that interconnects the components of split-system air conditioners and heat pumps, variable refrigerant flow systems, direct-expansion coils, computer room units, and packaged equipment supplied with a field-piped condensing section. Covers tube material and temper, joining methods and brazing filler metal, braze purge, field-installed specialties, line routing, oil return, insulation and its vapor seal, supports and seismic restraint, penetrations and firestopping, refrigerant concentration limits and the detection and mitigation provisions that go with mildly flammable refrigerants, piping identification, and the pressure test, evacuation, decay test, and charging sequence that puts the system into service.
Specifying matched split-system unitary air conditioners and air-source heat pumps, including ducted split systems (outdoor condensing/heat-pump unit matched to an indoor air handler or coil) and single-zone ductless mini-split systems, serving residential, light-commercial, and small-zone applications.
Independent third-party testing, adjusting, and balancing (TAB) of HVAC air and hydronic systems for new construction and major renovation of commercial, institutional, and industrial buildings. Covers TAB agency and personnel qualifications; instrument selection and calibration; preliminary, full, and final TAB reports; air-side procedures (duct traverse, terminal device measurement, outdoor air verification, fan curve verification); hydronic procedures (flow station readings, coil balancing valve adjustment, pump curve verification); sound and vibration spot checks; deficiency reporting back to the installing contractors; and seasonal re-balance work. TAB shall conform to NEBB Procedural Standards for Testing, Adjusting, and Balancing of Environmental Systems (current edition), AABC National Standards for Total System Balance (current edition), or ASHRAE 111, as selected by the Engineer.
Variable refrigerant flow (VRF/VRV) air-conditioning and heat pump systems serving commercial, institutional, and multifamily buildings, in which one or more inverter-driven condensing units circulate refrigerant through a piped network to multiple indoor fan-coil units, each metered by an electronic expansion valve. Covers heat pump (cooling-or-heating) and heat recovery (simultaneous cooling and heating) systems, air-cooled and water-source (water-cooled) condensing units, ducted and non-ducted indoor unit types, branch controllers and refrigerant selector boxes, A2L refrigerant safety and leak detection, and coordination of a dedicated outdoor air system for ventilation.