2,400+ Definitions

HVAC GLOSSARY

Every HVAC term, acronym, and industry phrase — defined in plain English.

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Control System Design

Control System Design specifies the hardware, software, and logic sequences…

Control Transformer

A control transformer is a step-down transformer that reduces line…

A Control Valve is an actuated device that modulates fluid…

Controlled Environment

A controlled environment is a space where temperature, humidity, air…

Convection is the transfer of thermal energy through the movement…

A convector is a heating device that transfers warmth from…

A duct fitting in which two airstreams merge into a…

A cool roof is a roofing system with high solar…

A cooling coil is a heat exchanger that removes thermal…

Cooling Degree Hours

The sum of hourly differences between outdoor dry-bulb temperature and…

Cooling load is the rate at which heat must be…

Cooling Load Calculation

Cooling load calculation determines the total heat removal capacity (in…

Cooling Load Temperature Difference

A tabulated equivalent temperature difference used with the U-factor of…

Cooling Seasonal Performance Factor

Cooling Seasonal Performance Factor (CSPF) measures the total cooling output…

A cooling tower is a heat rejection device that transfers…

Cooling Tower Blowdown

Blowdown is the controlled release of concentrated circulating water from…

Cooling Tower Chemical Treatment

Cooling tower chemical treatment involves adding specialized biocides, corrosion inhibitors,…

Cooling Tower Efficiency

Cooling tower efficiency measures how effectively a tower removes heat…

Cooling Tower Fan Control

The modulation of cooling tower fan speed or staging to…

Cooling Tower Makeup Water

Makeup water is fresh water added to the cooling tower…

COP (Coefficient of Performance) measures the ratio of heat output…

COP (Coefficient of Performance)

Coefficient of Performance (COP) measures the efficiency of a heat…

Copper pipe is a rigid or semi-rigid tubing made from…

Core Depressor Tool

A specialized valve stem wrench or fitting adapter used to…

Counter Flow Heat Exchanger

A counter flow heat exchanger operates with fluids moving in…

Counterflow Tower

A counterflow cooling tower directs air vertically upward while water…

CPVC (chlorinated polyvinyl chloride) pipe is a rigid plastic tubing…

A Computer Room Air Conditioner (CRAC) unit is a close-control…

Crankcase Heater

A crankcase heater is a small electrical resistance heating element…

Crawl Space Encapsulation

Crawl space encapsulation is the process of sealing and conditioning…

critical point (refrigerant)

The thermodynamic state at which the distinction between liquid and…

In a multi-zone HVAC system, the zone that requires the…

Cross Flow Heat Exchanger

A cross flow heat exchanger has fluids moving perpendicular to…

Cross-Contamination

In heat recovery ventilators, the unintended transfer of exhaust air…

The transmission of sound from one room to another through…

Crossflow Tower

A crossflow cooling tower directs air horizontally across falling water…

CSA C22.2 is the Canadian safety standard series for electrical…

A curb is a structural frame or raised base that…

A starting relay that senses the high inrush current in…

The Cv value is a numerical coefficient that quantifies the…

The Cx Authority is the designated individual or firm responsible…

Damper Actuator

A damper actuator is an electromechanical or pneumatic device that…

The Darcy-Weisbach equation is a theoretical formula calculating pressure drop…

Data Center ASHRAE Classes

ASHRAE classes categorize data center environments based on allowable temperature,…

Data Center Cooling

Data Center Cooling encompasses the specialized HVAC systems, strategies, and…

Data Center Cooling Infrastructure

Data center cooling infrastructure removes heat generated by thousands of…

A data logger is an electronic device that automatically records…

Data logging is the automated collection and storage of system…