2,400+ Definitions
HVAC GLOSSARY
Every HVAC term, acronym, and industry phrase — defined in plain English.
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…
Home Automation
Home Automation refers to the integration of electrical systems and…
Home Battery System
A home battery system stores electrical energy generated by solar…
Home Mode
Home mode is the default HVAC operating schedule that maintains…
HOMES Rebate Program
The HOMES Rebate Program provides federal incentives for residential energy…
Hospital HVAC
Hospital HVAC systems provide infection control, humidity management, and reliable…
Hot Aisle Containment
Hot aisle containment isolates warm return air from server equipment…
Hot Gas Bypass
A hot gas bypass is a refrigeration control method that…
Hot Gas Line
The hot gas line, also known as the discharge line,…
Hot Gas Reheat
Hot Gas Reheat (HGRH) is a dehumidification strategy used in…
Hot Surface Igniter
A hot surface igniter is an electric heating element that…
Hot Water Coil
A hot water coil is a heating heat exchanger that…
Hot Water Plant
A Hot Water Plant is a centralized heating facility that…
Hot Water Recirculation Pump
A hot water recirculation pump continuously circulates heated water through…
Hot Wire
The hot wire carries electrical current from the source to…
Hot Wire Anemometer
A hot wire anemometer measures air velocity by detecting cooling…
Hourly Analysis Program
Hourly Analysis Program (HAP) is an energy simulation methodology and…
Housewrap
Housewrap is a weather-resistant membrane installed over building sheathing to…
HRV (Heat Recovery Ventilator)
A Heat Recovery Ventilator (HRV) provides controlled fresh air ventilation…
HSPF
HSPF (Heating Seasonal Performance Factor) measures the total heating output…
HSPF2
HSPF2 (Heating Seasonal Performance Factor 2) is the federal standard…
Humidifier
A humidifier is an HVAC component designed to increase the…
Humidifier (Whole-House)
A whole-house humidifier adds moisture to the air distributed through…
Humidistat
A humidistat is a control device that measures indoor relative…
Humidity
Humidity is the amount of water vapor present in the…
Humidity Data Logger
A humidity data logger continuously records relative humidity (RH) levels…
Humidity Sensor
A humidity sensor detects and measures moisture content in air,…