2,400+ Definitions

HVAC GLOSSARY

Every HVAC term, acronym, and industry phrase — defined in plain English.

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Anemometer
An anemometer is an instrument that measures air velocity and…
Annual Energy Use
Annual Energy Use is the total amount of energy consumed…
Annual Fuel Utilization Efficiency
Annual Fuel Utilization Efficiency (AFUE) is a metric that expresses…
Annual HVAC Maintenance
Annual HVAC Maintenance is a comprehensive service performed once yearly…
Annualized Fuel Utilization Efficiency
Annualized Fuel Utilization Efficiency (AFUE) is a metric that expresses…
Ansul System
An Ansul System is an automatic fire suppression system specifically…
Anti Islanding
Anti-islanding is a safety feature in grid-connected photovoltaic systems that…
Apparent Power
Apparent power is the total electrical power supplied to an…
Appendix G
Appendix G is the section of ASHRAE 90.1 that establishes…
Apple HomeKit HVAC
Apple HomeKit HVAC enables control of compatible heating and cooling…
Applied Chiller
An applied chiller is a large-capacity, custom-engineered chilling system designed…
Approach Temperature
Approach temperature is the difference in degrees Fahrenheit between the…
Approach Temperature Method
The Approach Temperature Method is a performance evaluation technique used…
Approach Temperature Tower
Approach temperature is the difference between the cooled water leaving…
Aquastat
An aquastat is a temperature-sensitive control device designed to measure…
Arc Fault Circuit Interrupter
An Arc Fault Circuit Interrupter (AFCI) is a protective device…
ARI
ARI is the Air-Conditioning and Refrigeration Institute, the predecessor organization…
ASHRAE
ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) is…
ASHRAE 135
ASHRAE 135 defines BACnet, an open protocol standard for building…
ASHRAE 15
Definition ASHRAE 15 is the Safety Standard for Refrigeration Systems…
ASHRAE 15 Safety Standard
ASHRAE 15 is the primary safety standard for refrigerant classification…
ASHRAE 189.1
ASHRAE 189.1, officially titled Standard for the Design of High-Performance…
ASHRAE 34
Definition ASHRAE 34 is the Designation and Safety Classification of…
ASHRAE 52.2
Definition ASHRAE 52.2 is the Method of Testing General Ventilation…
ASHRAE 55
ASHRAE 55 is a standard that defines thermal comfort conditions…
ASHRAE 55 Compliance
ASHRAE 55 is the American Society of Heating, Refrigerating and…
ASHRAE 62.1
ASHRAE 62.1 sets minimum ventilation and indoor air quality standards…
ASHRAE 62.1 Compliance
ASHRAE 62.1 is the primary standard governing indoor air quality…
ASHRAE 62.2
ASHRAE 62.2 establishes ventilation and indoor air quality standards specifically…
ASHRAE 90.1
ASHRAE 90.1 is the primary energy efficiency standard for commercial…
ASHRAE 90.1 2013
ASHRAE Standard 90.1-2013 establishes minimum energy efficiency requirements for commercial…
ASHRAE 90.1 2016
ASHRAE Standard 90.1-2016 sets minimum energy efficiency criteria for commercial…
ASHRAE 90.1 2019
ASHRAE Standard 90.1-2019 establishes minimum energy efficiency standards for commercial…
ASHRAE 90.1 2022
ASHRAE Standard 90.1-2022 sets minimum energy efficiency requirements specifically for…
ASHRAE 90.1 Baseline
ASHRAE 90.1 Baseline is the reference standard for energy performance…
ASHRAE 90.1 Compliance
ASHRAE 90.1 Compliance confirms that a building’s HVAC systems, envelope,…
ASHRAE 90.2
ASHRAE 90.2, officially titled “Energy-Efficient Design of Low-Rise Residential Buildings,”…
ASHRAE Design Data
ASHRAE design data comprises standardized tables of outdoor temperature, humidity,…
ASHRAE Sound Guidelines
ASHRAE Sound Guidelines are technical recommendations published in ASHRAE Handbook…
Aspect Ratio
Aspect ratio in HVAC refers to the proportional relationship between…
Asthma Trigger
An asthma trigger is any airborne substance or environmental condition…
Atmospheric Burner
An atmospheric burner is a gas flame ignition device that…
Attic Fan
An attic fan is an electrically powered ventilation device installed…
AutoCAD MEP
AutoCAD MEP is Autodesk’s 2D and 3D design software specifically…
Automated Demand Response
Automated Demand Response (ADR) is a technology-enabled system that automatically…
Automated FDD
Automated Fault Detection and Diagnosis (FDD) systems use algorithms and…
Auxiliary Heat
Auxiliary heat is a secondary or supplemental heating source integrated…
Avoided Cost Rate
The avoided cost rate is the price a utility company…