2,400+ Definitions
HVAC GLOSSARY
Every HVAC term, acronym, and industry phrase — defined in plain English.
Carbon Free Energy
Carbon Free Energy is electricity generated without producing carbon dioxide…
Carbon Monoxide
Carbon monoxide (CO) is a toxic, odorless, colorless gas produced…
Carbon Monoxide Sensor
A carbon monoxide sensor detects dangerous levels of carbon monoxide…
Carbon Monoxide Testing
Carbon monoxide (CO) testing detects this colorless, odorless toxic gas…
Carbon Neutral
Carbon neutral refers to operating an HVAC system or facility…
Carbon Offset
A Carbon Offset is a tradable credit representing one metric…
Carnot COP
Carnot COP is the theoretical maximum coefficient of performance for…
Carnot Cycle
The Carnot Cycle is an idealized thermodynamic cycle consisting of…
Carpet Emissions
Carpet emissions include volatile organic compounds from fibers, backing materials,…
Carrier Equation
An empirical formula developed by Willis Carrier for calculating the…
Carrier HAP
Carrier HAP (Hourly Analysis Program) is Carrier Corporation’s proprietary building…
Cartridge Filter
Cartridge filters are cylindrical filter elements with pleated media that…
Cascade Control
A control strategy where the output of a primary (master)…
Cascade Refrigeration
Cascade refrigeration uses two or more separate refrigeration cycles operating…
Cascade Refrigeration System
A refrigeration arrangement using two separate refrigerant circuits at different…
Cassette Indoor Unit
A ceiling-recessed indoor unit that mounts flush with the ceiling…
Category I Appliance
A non-positive-pressure vented appliance with flue gases hot enough to…
Category IV Appliance
A positive-pressure flue gas venting classification for appliances with flue…
Cavitation
The formation and violent collapse of vapor bubbles inside a…
Cavity Insulation
Cavity insulation is thermal material installed within the hollow spaces…
CEE Qualified
CEE Qualified designation indicates that an HVAC product meets the…
CEE Tier
CEE Tier is a classification system developed by the Consortium…
CEER
CEER, or Combined Energy Efficiency Ratio, is a metric used…
Ceiling Access Panel
A ceiling access panel is a removable or hinged opening…
Ceiling Diffuser
A ceiling diffuser is a supply air terminal mounted flush…
Ceiling Fan
A ceiling fan is a mechanical ventilation device mounted to…
Ceiling Fan CFM
Ceiling fan CFM is the cubic feet per minute of…
Ceiling Fan Efficiency
Ceiling fan efficiency measures how effectively a fan converts electrical…
Ceiling Plenum
The concealed space between a suspended ceiling and the floor…
Cellulose Insulation
Cellulose insulation is a loose-fill or blown material composed primarily…
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…