2,400+ Definitions
HVAC GLOSSARY
Every HVAC term, acronym, and industry phrase — defined in plain English.
Galvanized Pipe
Galvanized pipe is steel tubing coated with a protective zinc…
gas cooler
A heat exchanger used in transcritical CO2 refrigeration systems to…
Gas Furnace
A gas furnace is a heating appliance that burns natural…
Gas Phase Filtration
Gas phase filtration is a specialized air treatment process that…
Gas Pressure Manometer
A precision low-pressure instrument used to measure natural gas or…
Gas Valve
A gas valve is an electronically controlled device that regulates…
Gas Water Heater
A gas water heater uses natural gas or propane fuel…
Gate Valve
A gate valve is a linear flow control device that…
Gate Valve Plumbing
A gate valve is a shutoff valve that uses a…
Geofencing HVAC
Geofencing HVAC is a location-based control technology that uses smartphone…
Geothermal Heat Pump
A geothermal heat pump (GHP), also called a ground-source heat…
Geothermal Installation
Geothermal installation involves drilling ground loops and connecting them to…
Germicidal UV
Germicidal UV (ultraviolet-C light at 254 nanometers wavelength) destroys microorganism…
GFCI
GFCI stands for Ground Fault Circuit Interrupter, a critical safety…
Gigawatt
A gigawatt (GW) is a unit of power equal to…
Global Warming Potential Limit
A Global Warming Potential (GWP) Limit is a regulatory threshold…
Globe Valve
A Globe Valve is a linear-motion shutoff valve with an…
Glycol
Glycol is an organic antifreeze and heat transfer fluid used…
Glycol Chiller
A glycol chiller is a refrigeration system that circulates a…
Glycol Percentage
The concentration of ethylene or propylene glycol in a hydronic…
Glycol Runaround
A glycol runaround system circulates a water-glycol mixture through two…
Glycol Secondary Loop
A refrigeration system configuration in which a chilled glycol and…
Google Home HVAC
Google Home HVAC enables control of heating and cooling systems…
GPM
GPM stands for gallons per minute, a measurement of fluid…
Grains of Moisture
Grains of moisture measure the absolute humidity content in air,…
Gravity Damper
A gravity damper is a passive, motorless damper that uses…
Grease Duct
A grease duct is the ductwork component of a kitchen…
Grease Filter
A grease filter is a mechanical component installed in Type…
Green Button Data
Green Button Data is a standardized format for downloading energy…
Green Globes
Green Globes is a web-based building environmental design and management…
Green Mortgage
A green mortgage is a specialized home loan that recognizes…
Green Power Purchase
A Green Power Purchase is the acquisition of electricity from…
Green Roof
A green roof is a vegetated roofing system where living…
Grid Defection
Grid defection occurs when customers disconnect from the utility grid…
Grid Frequency
Grid frequency is the rate at which alternating current (AC)…
Grid Interactive
Grid-interactive HVAC systems communicate with the electricity grid to optimize…
Grid Interactive HVAC
Grid Interactive HVAC systems are smart heating and cooling units…
Grid Stability
Grid stability refers to the electrical grid’s ability to maintain…
Grid Tie Inverter
A grid tie inverter converts DC power from solar panels…
Grid Tied System
A grid-tied solar system connects directly to the utility grid…
Grid Voltage
Grid voltage is the electrical potential difference maintained throughout the…
Grille Neck
The duct connection opening at the back of a return…
Ground Fault Circuit Interrupter
A Ground Fault Circuit Interrupter (GFCI) is a specialized electrical…
Ground Fault Protection
A protective function that detects current flowing to ground through…
Ground Heat Exchanger
The buried or submerged piping circuit in a geothermal system…
Ground Mount Solar
Ground mount solar systems position photovoltaic panels on metal or…
Ground Source Heat Pump
A Ground Source Heat Pump (GSHP), also known as a…
Ground Wire
The ground wire provides a safety path for electrical current…