2,400+ Definitions
HVAC GLOSSARY
Every HVAC term, acronym, and industry phrase — defined in plain English.
Halide Torch
A halide torch is a flame-based leak detection tool that…
Hard Start
A hard start kit is an electrical device that provides…
Hard Start Kit
A hard start kit is a capacitor assembly that provides…
Harmonic Distortion
Harmonic distortion is the presence of electrical frequencies at multiples…
Hazen Williams
The Hazen-Williams equation is an empirical formula used to calculate…
HCFC Refrigerant
HCFC refrigerants (hydrochlorofluorocarbons) are transitional compounds containing hydrogen, chlorine, fluorine,…
Heat
Heat is the transfer of thermal energy between systems, objects,…
Heat Anticipator
A heat anticipator is a small, adjustable resistive device located…
Heat Capacity
Heat capacity is the amount of thermal energy required to…
Heat Engine
A heat engine is a device that converts thermal energy…
Heat Exchanger
The heat exchanger in a gas furnace is the component…
Heat Exchanger Inspection
A heat exchanger inspection examines the furnace or air handler…
Heat Flux
Heat flux is the rate of heat energy transfer per…
Heat Load
Heat load (also called heating load or heat loss) is…
Heat Pipe
A heat pipe is a sealed copper or aluminum tube…
Heat Pump
A heat pump is an HVAC system that moves heat…
Heat Pump Installation
Heat pump installation is the process of mounting and connecting…
Heat Pump Thermostat
A heat pump thermostat is specifically designed to manage heat…
Heat Pump Water Heater
A heat pump water heater (HPWH) uses electricity and refrigerant-based…
Heat Recovery
Heat recovery systems capture thermal energy from exhaust air, wastewater,…
Heat Recovery Chiller
A heat recovery chiller is a refrigeration system engineered to…
Heat Recovery Ventilation
Heat Recovery Ventilation (HRV) transfers thermal energy from exhaust air…
Heat Transfer
Heat transfer is the movement of thermal energy from a…
Heating Coil
A heating coil is a heat exchanger that raises the…
Heating Load Calculation
Heating load calculation determines the heat input (in BTU/h or…
Heating Seasonal Performance Factor
Heating Seasonal Performance Factor (HSPF) measures the total heating output…
HEEHRA
HEEHRA stands for Home Energy Efficiency Retrofit and Rebate Act,…
HEMS
HEMS stands for Home Energy Management System, an integrated platform…
HEPA Air Purifier
HEPA air purifiers are standalone or integrated units using High-Efficiency…
HEPA Filter
A HEPA filter is a high-efficiency particulate air filter that…
HEPA Filtered Room
A HEPA filtered room uses High-Efficiency Particulate Air filters to…
HFC Development
Hydrofluorocarbons (HFCs) were developed in the 1990s as replacements for…
HFC Phase Down
The HFC Phase Down is a scheduled reduction in hydrochlorofluorocarbon…
HFC Phasedown Schedule
The HFC Phasedown Schedule is a federally mandated program that…
HFC Refrigerant
HFC refrigerants (hydrofluorocarbons) are synthetic compounds containing hydrogen, fluorine, and…
HFO Refrigerant
HFO refrigerants (hydrofluoroolefins) are third-generation synthetic refrigerants containing hydrogen, fluorine,…
High Efficiency Electric Home Rebate
The High Efficiency Electric Home Rebate is a federal incentive…
High Efficiency Furnace
A high-efficiency furnace is a condensing heating system that achieves…
High Pressure Category
The High Pressure Category covers air conditioning and refrigeration systems…
High Pressure Switch
A high pressure switch is a safety control device installed…
High Superheat
High superheat occurs when refrigerant temperature exceeds the saturation temperature…
High Temperature Cascade
The high temperature cascade stage is the upper circuit in…
High Velocity System
A high velocity system is a type of HVAC system…
Hipot Test
A hipot test, or high potential test, applies a high…
Historian
A Historian is specialized software that stores, retrieves, and analyzes…
Holding Capacity
Holding capacity is the maximum heat load that a refrigeration…
Holiday Schedule
Holiday Schedule is a programmed control setting that automatically suspends…
Home Assistant HVAC
Home Assistant HVAC refers to heating, ventilation, and air conditioning…