2,400+ Definitions

HVAC GLOSSARY

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

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MW
A megawatt (MW) represents one million watts or 1,000 kilowatts…
Natatorium
A natatorium is an enclosed indoor swimming facility designed with…
NATE
NATE is the North American Technician Excellence organization, a nonprofit…
NATE Certification
NATE (North American Technician Excellence) is the leading independent certification…
NATE Certified Technician
A NATE certified technician is an HVAC professional who has…
National Electrical Code
The National Electrical Code (NEC) is the model electrical safety…
Natural Gas
Natural gas is a fossil fuel composed primarily of methane…
Natural Refrigerant
Natural refrigerants are cooling fluids derived from substances found in…
Natural Ventilation
Natural ventilation uses passive air movement through windows, doors, and…
Natural Ventilation Comfort
Natural Ventilation Comfort refers to the thermal and air quality…
Navisworks
Navisworks is Autodesk’s project review software that aggregates BIM models…
NC Curve
An NC curve is a graphical representation of maximum acceptable…
NEC
NEC is the abbreviation for the National Electrical Code, the…
Needlepoint Bipolar Ionization
Needlepoint bipolar ionization (NBPI) is an air purification technology that…
Negative Pressure Room
A negative pressure room maintains air pressure lower than surrounding…
Net Billing
Net billing is a solar compensation model where homeowners receive…
Net Energy Metering
Net energy metering (NEM) is a billing arrangement that credits…
Net Integrated Part Load Value
Net Integrated Part Load Value (NIPLV) is a single-number efficiency…
Net Metering
Net metering allows buildings with on-site renewable energy systems (primarily…
Net Zero
Net zero refers to a building or facility that produces…
Net Zero Energy
Net Zero Energy (NZE) describes buildings that produce as much…
Neutral Wire
The neutral wire completes the electrical circuit by providing a…
New York Energy Code
The New York Energy Code (NYEC) is the state’s comprehensive…
NFPA 54
NFPA 54 is the National Fuel Gas Code establishing safety…
NFPA 58
NFPA 58, officially titled the Liquefied Petroleum Gas Code, is…
NFPA 70
NFPA 70, commonly known as the National Electrical Code (NEC),…
NFPA 70 (Electrical Code)
NFPA 70, the National Electrical Code (NEC), governs all electrical…
NFPA 90A
NFPA 90A is the National Fire Protection Association standard addressing…
NFPA 90B
NFPA 90B is the National Fire Protection Association standard addressing…
Night Flush Cooling
Night Flush Cooling uses ventilation of outdoor air during cool…
Night Purge
Night Purge is a controlled ventilation process that exchanges indoor…
Night Setback
Night Setback is a scheduled temperature adjustment that reduces heating…
Nitrogen Dioxide
Nitrogen dioxide (NO2) is a harmful gas produced by combustion…
Nitrogen Pressure Test
A nitrogen pressure test involves pressurizing HVAC system components with…
Nitrogen Purge
Nitrogen purge is the continuous flow of inert nitrogen gas…
No Rinse Coil Cleaner
No rinse coil cleaner is a chemical solution designed to…
Noise Criteria
Noise Criteria (NC) is a rating system that specifies acceptable…
Non Coincident Peak
Non coincident peak represents the sum of individual zone or…
Non Condensable Gas
Non-condensable gases are atmospheric gases like nitrogen and oxygen that…
NPLV
NPLV, or Non-Standard Part Load Value, is a single-number metric…
O M Manual
An O M (Operations and Maintenance) Manual is a comprehensive…
Occupancy Sensor
An occupancy sensor automatically detects human presence in a room…
Occupied Mode
Occupied Mode is an operational state where HVAC systems actively…
Occupied Space Refrigerant Limit
The occupied space refrigerant limit is the maximum allowable charge…
Occupied Zone
The occupied zone is the region within a conditioned space…
Odor Control
Odor control refers to the removal or neutralization of unwanted…
ODP Motor
ODP (Open Drip-Proof) Motor features an open design with ventilation…
Off Gassing
Off gassing is the release of volatile organic compounds (VOCs)…