2,400+ Definitions
HVAC GLOSSARY
Every HVAC term, acronym, and industry phrase — defined in plain English.
Latent Heat of Vaporization
Latent heat of vaporization is the energy required to convert…
Latent Heat Ratio
Latent Heat Ratio (LHR) measures the proportion of total cooling…
Latent Heat Storage
Latent heat storage is a thermal energy storage method that…
LCOE
LCOE (Levelized Cost of Energy) is the average cost per…
Lead Acid Battery
Lead acid batteries are electrochemical devices using lead oxide cathodes…
Leak Testing
Leak testing is the diagnostic process of detecting refrigerant leaks…
Learning Thermostat
A learning thermostat is an intelligent control device that automatically…
LEED
Definition Leadership in Energy and Environmental Design (LEED) is a…
LEED Certification
LEED Certification is an official credential awarded by the U.S.…
LEED Certified
LEED Certified is the entry-level LEED credential, awarded to buildings…
LEED Energy Credit
LEED Energy Credits are certification points awarded for demonstrated energy…
LEED Gold
LEED Gold is the third-highest certification tier awarded to buildings…
LEED Platinum
LEED Platinum is the highest LEED certification tier, awarded to…
LEED Point
A LEED Point represents one credit earned toward LEED certification,…
LEED Silver
LEED Silver is the second-lowest LEED certification tier, awarded to…
Legionella Prevention
Legionella prevention encompasses water treatment strategies and maintenance protocols designed…
Levelized Cost of Energy
Levelized Cost of Energy (LCOE) is the total lifecycle cost…
Licensed Contractor
A licensed contractor is a business entity or individual authorized…
Limit Switch
A limit switch is a safety device that automatically opens…
Limit Switch Test
A limit switch test checks whether furnace or boiler temperature-limiting…
Line Set Cover
A line set cover is a protective conduit or sleeve…
Line Set Insulation
Line set insulation is foam or flexible rubber material wrapped…
Linear Diffuser
A linear diffuser is an elongated air distribution outlet featuring…
Linear Power Warranty
A linear power warranty guarantees solar panel output declines at…
Linear Valve
A linear valve is a control valve where equal increments…
Lineset
A lineset is the complete assembly of refrigerant carrying tubes,…
Liquid Cooling Data Center
A Liquid Cooling Data Center uses water, oil, or other…
Liquid Desiccant
Liquid desiccant cooling uses aqueous solutions, typically lithium chloride or…
Liquid Line
The liquid line is the section of refrigerant piping in…
Liquid Line Filter Drier
A liquid line filter drier is a refrigeration system component…
Lithium Bromide Chiller
A lithium bromide chiller is an absorption cooling system that…
Lithium Iron Phosphate Battery
Lithium Iron Phosphate (LiFePO₄) batteries are rechargeable energy storage systems…
Load Calculation
A load calculation determines how much heating and cooling capacity…
Load Duration Curve
A load duration curve is a graphical representation that ranks…
Load Forecasting
Load forecasting estimates the amount of electrical power that will…
Load Shedding
Load Shedding is the controlled reduction or disconnection of electrical…
Load Shifting
Load shifting is the strategy of moving HVAC energy consumption…
Local Exhaust
Local exhaust systems capture air contaminants directly at their point…
Location Based Control
Location based control is an HVAC technology that adjusts heating…
Locked Rotor Amps
Locked Rotor Amps (LRA) is the maximum current a motor…
Lockout Relay
A lockout relay is a safety device used in HVAC…
Low Ambient Control
Low Ambient Control refers to a set of strategies and…
Low GWP Refrigerant
Low GWP refrigerants are cooling fluids with global warming potential…
Low Pressure Category
The Low Pressure Category includes HVAC systems and large appliances…
Low Pressure Switch
A Low Pressure Switch (LPS) is a safety device installed…
Low Refrigerant
Low refrigerant indicates the system contains less than the manufacturer-specified…
Low Temperature Cascade
The low temperature cascade stage is the coldest circuit in…
Low Velocity Duct
A low velocity duct is an HVAC ductwork system designed…