2,400+ Definitions

HVAC GLOSSARY

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

All A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Pipe Insulation
Pipe insulation is a protective covering applied to hot or…
Pipe Pressure Drop
Pipe pressure drop is the reduction in pressure that occurs…
Pipe Schedule
A Pipe Schedule is a detailed table specifying all piping…
Pipe Sizing
Pipe sizing is the process of selecting appropriate pipe diameters…
Pipe Slope
Pipe slope is the intentional grade or tilt applied to…
Pipe Support
A pipe support is a structural element that bears pipe…
Pipe Velocity
Pipe velocity measures the speed at which fluid flows through…
Piping System Design
Piping System Design involves sizing and routing water or refrigerant…
Pitot Tube Traverse
A pitot tube traverse is a method for measuring air…
Plate Heat Exchanger
A plate heat exchanger consists of thin metal plates stacked…
Pleated Filter
Pleated filters feature accordion-like folds in the filter media that…
Plenum
A plenum is a chamber or box used to distribute…
Plenum Rated
Plenum rated refers to materials that meet strict fire safety…
Plenum Space
Plenum space is the cavity or chamber above a suspended…
PM 2.5
PM2.5 refers to particulate matter with a diameter of 2.5…
PMV
PMV (Predicted Mean Vote) is a numerical index that predicts…
Pneumatic Actuator
A pneumatic actuator uses compressed air pressure (typically 15-25 PSI)…
Point of Use Water Heater
A point of use water heater is a compact unit…
Points List
A Points List is a comprehensive inventory of all controllable…
Polycrystalline Solar Panel
A polycrystalline solar panel is manufactured from multiple silicon crystals…
Polyester Filter
Polyester filters utilize synthetic polyester fibers as the primary media…
Polytropic Compression
Polytropic compression is a more realistic refrigerant compression model incorporating…
Pool Dehumidification
Pool dehumidification is the process of removing excess moisture from…
Pool Heating
Pool heating is the process of raising and maintaining swimming…
Pool Solar Panel
A pool solar panel is an individual collector module that…
Positive Pressure Room
A positive pressure room maintains air pressure higher than adjacent…
Potassium Permanganate
Potassium permanganate (KMnO₄) is an oxidizing chemical compound used in…
Potential Relay
A potential relay is an electromagnetic switching device that removes…
Pounds per Square Inch
Pounds per Square Inch (PSI) is a unit of pressure…
Power Burner
A power burner is a gas burner equipped with a…
Power Factor
Power factor is the ratio of real power to apparent…
Power Factor Correction
Power factor correction is the installation of capacitors or other…
Power Meter
A power meter is an electronic instrument that measures electrical…
Power Optimizer
A power optimizer is a device installed on individual solar…
Power Purchase Agreement
A Power Purchase Agreement (PPA) is a contractual arrangement in…
Power Quality
Power quality refers to the consistency and purity of electrical…
Power Usage Effectiveness
Power Usage Effectiveness (PUE) is a metric measuring the ratio…
Power Vent
A power vent uses an electric blower or fan to…
Powerwall
Powerwall is a lithium-ion home battery system manufactured by Tesla…
PPD
PPD (Predicted Percentage Dissatisfied) quantifies the percentage of occupants expected…
Pre Cool
Pre Cool is the practice of cooling a building below…
Pre Cool Coil
A pre-cool coil removes heat from outdoor air before it…
Pre Heat
Pre Heat is the practice of heating a building above…
Precision Cooling
Precision cooling, also known as close control cooling, refers to…
Predicted Mean Vote
Predicted Mean Vote (PMV) is a thermal comfort index that…
Predicted Percentage Dissatisfied
Predicted Percentage Dissatisfied (PPD) is a metric that quantifies the…
Predictive Maintenance
Predictive maintenance uses performance data and trend analysis to forecast…
Press Fit Fitting
Press fit fittings are mechanical connectors that join copper or…