2,400+ Definitions
HVAC GLOSSARY
Every HVAC term, acronym, and industry phrase — defined in plain English.
AHRI 920
AHRI 920 is the performance rating standard published by the…
AHRI Certified
AHRI Certified indicates that HVAC equipment has been independently tested…
AHRI Directory
The AHRI Directory is a comprehensive online database listing all…
AHRI Performance Certification
AHRI Performance Certification is the formal designation verifying that HVAC…
AIM Act
The American Innovation and Manufacturing (AIM) Act, enacted in 2020,…
Air Balance Report
An air balance report documents the distribution of conditioned air…
Air Balancing
Air balancing is the process of adjusting an HVAC system…
Air Barrier
An air barrier is a continuous layer of material or…
Air Changes per Hour
Air changes per hour (ACH) measures how many times total…
Air Cleaning
Air cleaning refers to the process of removing particulate matter,…
Air Conditioner
An air conditioner is a mechanical refrigeration system designed to…
Air Cooled Condenser
An air-cooled condenser is a heat exchange device that rejects…
Air Diffuser
An air diffuser is a duct terminal device that disperses…
Air Dilution
Air dilution is the process of introducing outdoor air into…
Air Distribution
Air distribution describes how conditioned air is delivered to and…
Air Equalizer
An air equalizer is a device or ductwork component designed…
Air Exchange Rate
Air exchange rate measures how frequently all air within a…
Air Filter
An air filter is a device composed of porous media…
Air Filtration
Air filtration removes particulate contaminants including dust, pollen, and debris…
Air Handler
An air handler (also called an air handling unit or…
Air Handler Installation
Air handler installation involves mounting an indoor evaporator coil and…
Air Handling Unit
An Air Handling Unit (AHU) is a large, enclosed assembly…
Air Infiltration
Air infiltration is the unintended leakage of outdoor air into…
Air Mixing Box
An air mixing box is a component in an HVAC…
Air Plenum
An air plenum is a chamber or duct section designed…
Air Purification
Air purification removes gases, odors, microorganisms, and chemical contaminants from…
Air Quality Index
The Air Quality Index (AQI) is a standardized numerical scale…
Air Quality Monitor
An air quality monitor is a device that measures multiple…
Air Register
An air register is an HVAC terminal device that delivers…
Air Sampling
Air sampling is an environmental monitoring technique that collects airborne…
Air Sealing
Air sealing is the process of identifying and closing unintended…
Air Separator
An Air Separator is a hydronic system component that removes…
Air Speed
Air speed is the velocity of air movement around an…
Air to Air Heat Exchanger
An air-to-air heat exchanger transfers sensible or total energy between…
Airflow Balancing
Airflow balancing adjusts dampers and registers throughout a duct system…
Airflow Check Annual
An annual airflow check verifies that the heating and cooling…
Airflow Measurement
Airflow measurement quantifies the volume of air moving through an…
Airflow Problem
An airflow problem occurs when insufficient air moves through the…
Alarm Management
Alarm management is the systematic configuration, filtering, notification, and response…
Alexa HVAC
Alexa HVAC refers to heating and cooling systems compatible with…
Algae Treatment
Algae treatment applies biocidal chemicals to condensate pans and drain…
Allergen
An allergen is a substance capable of triggering an adverse…
Alternating Current
Alternating current (AC) is electrical current that periodically reverses direction,…
American Innovation Manufacturing Act
The American Innovation Manufacturing (AIM) Act is comprehensive federal legislation…
AMI
AMI is the abbreviation for Advanced Metering Infrastructure, an integrated…
Ammonia Absorption Chiller
An ammonia absorption chiller uses aqueous ammonia solution as the…
Amp Draw
Amp draw is the electrical current in amperes that a…
Ampere
An ampere (A), also called amp, is the unit of…