2,400+ Definitions
HVAC GLOSSARY
Every HVAC term, acronym, and industry phrase — defined in plain English.
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 Handbook of Fundamentals
Comprehensive reference volume published by ASHRAE covering the scientific principles…
ASHRAE refrigerant designation
A standardized alphanumeric naming system defined in ASHRAE Standard 34…
ASHRAE Simplified Infiltration Model
A procedure in ASHRAE Handbook fundamentals that estimates infiltration from…
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…
Aspirating Psychrometer
A psychrometer that uses a small fan or aspirator to…
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…
Auto-Restart
A feature that causes a mini-split or VRF system to…
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…
Automatic Flow Limiter
A pre-set cartridge or insert installed in a hydronic circuit…
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…
Away Mode
Away mode is an HVAC operating schedule that automatically switches…
AWG
AWG stands for American Wire Gauge, the standard measurement system…
Azeotropic Blend
An azeotropic blend is a refrigerant mixture composed of two…
Backflow Preventer
A backflow preventer is a critical safety device that allows…
BACnet
BACnet is an open-source communication protocol standard developed by ASHRAE…
BACnet Interface
A communication gateway or built-in capability that allows a VRF…
BACnet IP
A BACnet network variant that encapsulates BACnet messages within UDP/IP…
BACnet MSTP
The Master-Slave Token-Passing physical layer and data link protocol variant…
Bag Filter
Bag filters are cylindrical or rectangular fabric containers that capture…
Balance Point Temperature
The outdoor temperature at which a heat pump’s heating capacity…
Balanced Flue
A sealed combustion system in which both the air intake…
Balanced Mechanical Ventilation
Balanced mechanical ventilation simultaneously supplies filtered fresh air and exhausts…
Balanced Ventilation
Balanced ventilation systems simultaneously supply and exhaust equal volumes of…
Balancing Damper
A balancing damper is a manually adjustable blade device installed…
Ball Valve
A Ball Valve is a quarter-turn shutoff valve featuring a…
Ball Valve Plumbing
A ball valve is a quarter-turn shutoff valve with a…
Ball Valve Service Valve
A full-port quarter-turn valve installed on compressor suction and discharge…
Balometer
A balometer is a specialized airflow measurement device that combines…
Barometric Damper
A weighted, hinged flap installed in the flue pipe of…