HVAC Glossary of Terms

Learn How to Speak Heating and Cooling

Two-Stage
Two levels of operation, which saves energy during non-peak cooling demands.

Three-Stage
More than one level of operation—low, medium and high—which saves energy during non-peak cooling demands.

Variable-Speed (also know as Inverter Technology)
Varying levels of operation based on cooling needs. This modulating technology provides more precise temperature control, lower humidity and greater efficiency.

Compressor
The compressor plays an integral role in cooling your home. It is the device responsible for pumping refrigerant through the refrigerant lines and the coil, making the transfer of heat from inside your house to the outdoors possible.

Indoor Air Quality (IAQ)
Refers to the air quality within buildings, especially as it relates to the health and comfort of building occupants.

Efficiency
Description for how effectively incoming energy is converted to outgoing energy. The higher the number, the more efficient the unit—and the lower the operating costs.

SEER 
Seasonal Energy Efficiency Rating is used to express the efficiency of an air conditioning unit, or an air conditioner in cooling mode. The higher the SEER rating, the more efficient the unit.

EER
Energy Efficiency Ratio is the cooling capacity of the air conditioner in BTUs per hour to the total electrical input in watts. This measure is determined by comparing test units to the Air Conditioning and Refrigeration Institute specifications