2,400+ Definitions
HVAC GLOSSARY
Every HVAC term, acronym, and industry phrase — defined in plain English.
Central Plant
A Central Plant is a centralized mechanical facility that generates…
Centralized Controller
A building-level interface device that allows monitoring and control of…
Centrifugal Chiller
A centrifugal chiller is a type of vapor-compression refrigeration system…
CFC Refrigerant
Chlorofluorocarbons (CFCs) are a class of synthetic organic compounds composed…
CFCs and Ozone Layer
Chlorofluorocarbons (CFCs) are industrial chemicals that release chlorine atoms when…
CFM
CFM stands for Cubic Feet per Minute and measures the…
CFM per Square Foot
A measure of supply or exhaust airflow density expressed as…
Characterized Control Valve
A characterized control valve is a modulating valve with an…
Charge Verification
Charge verification is the process of confirming that an air…
Charging Cylinder
A calibrated transparent cylinder graduated in ounces or pounds used…
Check Valve
A check valve is a one-way mechanical valve used in…
Check Valve Plumbing
A check valve is a one-way flow device that permits…
Chemical Storage Ventilation
Chemical storage ventilation systems manage hazardous vapors and fumes from…
Chemisorption
Chemisorption is a process where gas molecules chemically bond to…
Chilled Beam
A chilled beam is a ceiling-mounted heat exchanger that uses…
Chilled Mirror Hygrometer
A specific type of dew point hygrometer that uses a…
Chilled Water Coil
A chilled water coil is a heat exchanger that cools…
Chilled Water Delta-T
The temperature difference between return and supply chilled water, typically…
Chilled Water Plant
A Chilled Water Plant is a centralized cooling facility that…
Chilled Water Reset
A control strategy that raises the chilled water supply temperature…
Chilled Water System
A chilled water system is a centralized cooling arrangement that…
Chiller
A chiller is a refrigeration system designed to cool a…
Chiller Sequencing
The control strategy that determines when additional chillers in a…
Chimney Inspection
A chimney inspection evaluates the structural integrity, cleanliness, and proper…
CHP System
A CHP System integrates power generation and heat recovery equipment…
Circuit Balancing Valve
An adjustable valve installed on each hydronic circuit to restrict…
Circuit Board
A circuit board, formally known as a Printed Circuit Board…
Circuit Breaker
A circuit breaker is an automatic switching device that protects…
Circulator Pump
A Circulator Pump is a hydronic system component that creates…
Clam Shell Heat Exchanger
A traditional residential gas furnace heat exchanger design consisting of…
Clamp On Ammeter
A clamp on ammeter is a non-contact instrument that measures…
Clamp-On Ammeter
An electrical test instrument with a jaw that clamps around…
Clash Detection
Clash Detection is an automated process that identifies where HVAC…
Clean Room Classification
Clean room classification is a standardized system categorizing enclosed spaces…
Clean Room HVAC
Clean room HVAC systems maintain strict environmental controls including particle…
Clear-Field U-Factor
The thermal transmittance of a fenestration unit measured at the…
Closed Circuit Cooler
A closed circuit cooler is a heat rejection device that…
Closed System Plumbing
Closed system plumbing refers to a piping configuration where water…
Closed System Thermodynamics
A closed system has fixed boundaries that prevent mass transfer…
Closely Spaced Tees
A pair of tees installed on a common pipe with…
Clothing Insulation
Clothing insulation is the thermal resistance of garments worn by…
Cloud Connected HVAC
Cloud Connected HVAC refers to heating, ventilation, and air conditioning…
CO Analyzer
A portable gas detector calibrated specifically to measure carbon monoxide…
CO Detector
A CO detector is a wall-mounted or plug-in safety device…
CO Meter
A CO meter is a handheld instrument that measures carbon…
CO Monitoring Parking
CO monitoring in parking facilities uses electrochemical or infrared sensors…
CO2 Booster System
A CO2 booster system employs a parallel compressor configuration where…
CO2 Monitor
A CO2 monitor measures carbon dioxide concentration in indoor air,…