Air Conditioning Terms

Here is a glossary of commonly used air conditioning terms.

Straight Cool System – An air-conditioning system that includes a cooling cycle only. Gas, oil, or electric strip heating may be included in straight cool systems.

Strip Heating (or Resistance Heating)
– A form of heating, where air is blown over electrically heated metal coils and circulated into the living space.

Heat Pump System – Cooling and heating system that provides a cooling cycle during the summer and a heating cycle during the winter.

SEER (Seasonal Energy Efficiency Ratio)
– A measure of the average annual cooling efficiency of an air conditioner or heat pump. We recommend a minimum SEER of 14.0.

HSPF (Heating Seasonal Performance Factor)
– A measure of the average annual heating efficiency of a heat pump. We recommend an HSPF of greater than 7.7.

The higher the SEER or HSPF, the more efficient the model.

These are units of measure that determine an A/C system’s size:

BTU (British Thermal Unit)
– Used to describe how much cooling capacity a business needs.
Ton – A measure of the size or cooling capacity of an air conditioner. One ton is equal to 12,000 BTUs.