2,400+ Definitions
HVAC GLOSSARY
Every HVAC term, acronym, and industry phrase — defined in plain English.
CO2 Refrigeration
CO2 refrigeration uses carbon dioxide (R-744) as the working fluid…
CO2 Sensor
A CO2 sensor measures carbon dioxide concentration in indoor air,…
CO2-Based DCV
A form of demand control ventilation that uses carbon dioxide…
Coanda Effect
The tendency of a moving air jet to attach to…
Coefficient of Performance
A dimensionless ratio expressing the heat output or heat removal…
Coefficient of Performance Refrigeration
Coefficient of Performance (COP) for refrigeration is the ratio of…
Cogeneration
Cogeneration is a process that simultaneously produces electricity and useful…
Coil Circuiting
The internal arrangement of refrigerant or water passes within an…
Coil Cleaner Chemical
Coil Cleaner Chemical is a formulated solution designed to dissolve…
Coil Cleaning
Coil cleaning is the process of removing accumulated dirt, scale,…
Coil Cleaning Procedure
Coil Cleaning Procedure is the systematic process of removing dirt,…
Coil Coating
Coil coating is a protective layer applied to heat exchanger…
Coil Face Velocity
Coil face velocity is the linear speed (measured in feet…
Coil Fin Straightener
A coil fin straightener is a hand tool used to…
Coil Fouling Factor
The coil fouling factor is a dimensionless value representing the…
Coil Freeze
Coil freeze occurs when evaporator temperature drops below 32 degrees…
Coil Frosting Pattern
The visual distribution of frost accumulation across an evaporator coil…
Coil Rows
Coil rows refer to the number of horizontal layers of…
Coil Suppression Device
A component such as a diode, metal oxide varistor, or…
Coincident Peak
Coincident peak refers to the maximum simultaneous electrical demand or…
Coincident Wet Bulb
The mean wet-bulb temperature statistically associated with a given dry-bulb…
Cold Aisle Containment
Cold aisle containment encloses the front of server racks to…
Cold Climate Heat Pump
An air-source heat pump specifically engineered with enhanced vapor injection,…
Cold Plasma
Cold plasma is an ionization technology that generates activated ions…
Cold Room
A cold room is an insulated, walk-in refrigerated space maintained…
Combi Boiler
A combi boiler is a single, compact unit that provides…
Combined Energy Efficiency Ratio
Combined Energy Efficiency Ratio (CEER) measures the cooling efficiency of…
Combined Heat and Power
Combined Heat and Power (CHP) refers to energy systems that…
Combustion Air
Combustion air is the oxygen-containing air required for the chemical…
Combustion Air Opening
A code-required opening or duct that supplies outdoor or unconfined…
Combustion Analysis
Combustion analysis is the process of measuring the byproducts of…
Combustion Analyzer
A combustion analyzer is an electronic instrument that measures exhaust…
Combustion Chamber
The combustion chamber is the enclosed space within a furnace…
Combustion Efficiency
A measure of how effectively a burner converts fuel energy…
Combustion Efficiency Tester
An instrument that calculates the percentage of fuel energy converted…
Combustion Inspection
A combustion inspection analyzes gas furnace combustion efficiency by measuring…
Combustion Safety
Combustion safety refers to the protection systems and practices that…
Combustion Safety Test
A combustion safety test is a comprehensive inspection measuring carbon…
Commercial Refrigeration
Commercial refrigeration encompasses all industrial-scale cooling systems designed to preserve…
Commercial Solar
Commercial solar systems are larger photovoltaic installations designed for businesses,…
Commercial Water Heater
Commercial water heaters are high-capacity systems designed to meet hot…
Commissioning
Commissioning is the systematic process of testing, adjusting, and documenting…
Commissioning Balancing
Commissioning balancing is the comprehensive process of measuring and adjusting…
Commissioning Checklist
A commissioning checklist is a comprehensive verification document ensuring all…
Commissioning Plan
A commissioning plan is a written document outlining the scope,…
Commissioning Report
A Commissioning Report documents the verification and testing results of…
Commissioning Specification
A Commissioning Specification is a detailed set of requirements that…
Common Mode Choke
An inductor wound so that differential mode motor current passes…