2,400+ Definitions

HVAC GLOSSARY

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

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Product Data
Product data is manufacturer-supplied technical information including specifications, performance ratings,…
Programmable Thermostat
A programmable thermostat automatically adjusts heating and cooling setpoints according…
Propane Furnace
A propane furnace is a heating appliance that burns propane…
Propane Water Heater
A propane water heater burns liquefied petroleum gas (propane) in…
Property Assessed Clean Energy
Property Assessed Clean Energy (PACE) is a financing mechanism that…
Proportional Balancing
Proportional balancing is a simplified hydronic balancing method that adjusts…
Proportional Control
Proportional control modulates a valve or damper position continuously based…
Propylene Glycol Solar
Propylene glycol solar fluid is a non-toxic heat transfer liquid…
PSC Motor
A PSC (Permanent Split Capacitor) motor is a single-phase induction…
Psychrometric Chart
The psychrometric chart is a graphical representation of air properties…
Psychrometrics
Psychrometrics is the science of the thermodynamic properties of moist…
PTAC Installation
PTAC (Packaged Terminal Air Conditioner) installation involves mounting a self-contained…
PUE
PUE (Power Usage Effectiveness) measures data center energy efficiency by…
Pull Down Time
Pull down time is the duration required for a refrigeration…
Pulley Alignment
Pulley alignment is the critical adjustment process that ensures driving…
Pump Laws
Pump Laws are specific applications of the Affinity Laws that…
Push to Connect Fitting
Push to connect fittings provide quick, tool-free connections for plastic…
PV Powered Heat Pump
A PV powered heat pump uses photovoltaic electricity generation to…
PV System
A PV system is a complete solar energy installation that…
PV Wire
PV wire is a single-conductor, UV-resistant cable specifically engineered for…
PVC Flue
A PVC flue is a plastic exhaust pipe made from…
PVC Pipe
PVC (polyvinyl chloride) pipe is a rigid plastic tubing commonly…
PWM Controller
A PWM (Pulse Width Modulation) controller is a basic solar…
R Value
R Value measures the thermal resistance of insulation materials, indicating…
R-11
R-11, also known as Trichlorofluoromethane, is a chlorofluorocarbon (CFC) refrigerant…
R-12
R-12, also known as dichlorodifluoromethane, is a chlorofluorocarbon (CFC) refrigerant…
R-123
R-123, chemically known as 2,2-dichloro-1,1,1-trifluoroethane (CHCl₂CF₃), is a hydrochlorofluorocarbon (HCFC)…
R-1234yf
R-1234yf is a hydrofluoroolefin (HFO) refrigerant with an exceptionally low…
R-1234ze
R-1234ze is a hydrofluoroolefin (HFO) refrigerant with a GWP of…
R-124
R-124, also known as chlorotetrafluoroethane (chemical formula C₂HClF₄), is a…
R-125
R-125, also known as pentafluoroethane, is a hydrofluorocarbon (HFC) refrigerant…
R-1336mzz
R-1336mzz is a hydrofluoroolefin (HFO) refrigerant with the chemical formula…
R-134a
R-134a is a hydrofluorocarbon (HFC) refrigerant with zero ozone depletion…
R-152a
R-152a (1,1-Difluoroethane) is a hydrofluorocarbon (HFC) refrigerant with the chemical…
R-22
R-22, also known as chlorodifluoromethane, is a chlorofluorocarbon (CFC) refrigerant…
R-245fa
R-245fa (1,1,1,3,3-pentafluoropropane) is a hydrofluorocarbon (HFC) refrigerant with the chemical…
R-290
R-290 is a refrigerant-grade propane (C₃H₈) with a minimum purity…
R-32
R-32 is a hydrofluorocarbon (HFC) refrigerant with zero ozone depletion…
R-404A
R-404A is a hydrofluorocarbon (HFC) blend refrigerant composed of three…
R-407A
R-407A is a non-ozone depleting hydrofluorocarbon (HFC) refrigerant blend consisting…
R-407C
R-407C is a hydrofluorocarbon (HFC) blend refrigerant designed as a…
R-407F
R-407F is a zeotropic hydrofluorocarbon (HFC) refrigerant blend composed of…
R-408A
R-408A is a zeotropic refrigerant blend composed of R-22 (47%),…
R-409A
R-409A is a hydrochlorofluorocarbon (HCFC)-based refrigerant blend developed as a…
R-410A
R-410A is a hydrofluorocarbon (HFC) refrigerant that became the standard…
R-417A
R-417A is a non-ozone depleting hydrofluorocarbon (HFC) blend refrigerant composed…
R-421A
R-421A is a zeotropic blend refrigerant composed of 59% R-134a,…
R-422B
R-422B is a hydrofluorocarbon (HFC) refrigerant blend composed of R-125…