2,400+ Definitions
HVAC GLOSSARY
Every HVAC term, acronym, and industry phrase — defined in plain English.
Refrigerant Distributor
A refrigerant distributor is a device installed between an expansion…
Refrigerant GWP
Refrigerant GWP (Global Warming Potential) is a numerical rating measuring…
Refrigerant Leak
A refrigerant leak occurs when the sealed cooling system loses…
Refrigerant Leak Check Annual
An annual refrigerant leak check is a professional inspection using…
Refrigerant Leak Detection
Refrigerant leak detection is the process of locating refrigerant leaks…
Refrigerant Leak Sensor
A refrigerant leak sensor detects and alerts operators to the…
Refrigerant Line Set
A refrigerant line set is a pair or trio of…
Refrigerant Log
A Refrigerant Log is a detailed record documenting all refrigerant…
Refrigerant Management Plan
A Refrigerant Management Plan is a documented strategy that outlines…
Refrigerant ODP
Refrigerant ODP (Ozone Depletion Potential) is a relative measure of…
Refrigerant Pressure Check
A refrigerant pressure check measures high-side and low-side pressures in…
Refrigerant Purchase Record
A Refrigerant Purchase Record is documentation of all refrigerant acquisition…
Refrigerant Reclaim
Refrigerant reclaim is the industrial process of purifying used refrigerant…
Refrigerant Reclaiming
Refrigerant reclaiming is the process of reprocessing used or contaminated…
Refrigerant Recovery
Refrigerant recovery is the mandatory process of removing refrigerant from…
Refrigerant Recovery Cylinder
A refrigerant recovery cylinder is a specialized pressurized container designed…
Refrigerant Recycling
Refrigerant recycling is the process of cleaning used refrigerant extracted…
Refrigerant Safety Classification
Refrigerant Safety Classification is a standardized labeling system established by…
Refrigerant Tracking
Refrigerant Tracking is the systematic monitoring and documentation of refrigerant…
Refrigerant Weigh In
Refrigerant weigh in is the process of accurately measuring and…
Refrigeration Capacity
Refrigeration capacity is the maximum amount of heat that a…
Refrigeration Cycle
The refrigeration cycle is the thermodynamic process by which HVAC…
Refrigeration Cycle Efficiency
Refrigeration cycle efficiency measures how effectively a refrigeration system converts…
Refrigeration Effect
The refrigeration effect is the amount of useful cooling capacity…
Refrigeration Load
Refrigeration load is the total amount of heat that a…
Refrigeration System
A refrigeration system is a mechanical apparatus that transfers heat…
Relative Humidity
Relative humidity is the ratio of water vapor pressure in…
Relay
A relay is an electromechanical or solid-state switch that uses…
Relief Valve
A relief valve is a safety device that automatically opens…
Remote HVAC Control
Remote HVAC control allows users to adjust heating, cooling, and…
Renewable Energy
Renewable energy is power generated from naturally replenishing sources such…
Renewable Energy Certificate
A Renewable Energy Certificate (REC) is a market-based instrument that…
Reset Schedule
A reset schedule automatically adjusts HVAC setpoints based on outdoor…
Residential Solar
Residential solar refers to rooftop or ground-mounted photovoltaic systems installed…
Retro Commissioning
Retro commissioning is a systematic process of identifying and correcting…
Retrofit
A retrofit is the modification or replacement of existing HVAC…
Return Air Grille
A return air grille is a ventilation component installed over…
Return Duct
Return ducts transport air from occupied spaces back to the…
Reverse Return
A reverse return piping configuration routes the return water line…
Reversing Valve
A reversing valve is an electromechanical device installed in heat…
Reversing Valve Failure
Reversing valve failure occurs when the component that switches between…
Revit MEP
Revit MEP is Autodesk’s specialized BIM software designed for mechanical,…
Rigid Foam Board
Rigid foam board is a lightweight sheet insulation material manufactured…
Riser Diagram
A riser diagram is a vertical representation of piping or…
Rolling Brownout
A Rolling Brownout is a temporary, rotating reduction in electrical…
Roof Mount Solar
Roof mount solar refers to photovoltaic panels installed directly on…
Roof Reflectance
Roof reflectance, also called albedo, measures the percentage of solar…
Rooftop Equipment
Rooftop equipment includes HVAC units, cooling towers, air handling units,…