American Society of Heating, Refrigeration and Air Conditioning Engineers.

A type of current where the polarity is perpetually reversing, causing the directional flow in a circuit to reverse at regular intervals.

Air Conditioning Contractors of America.

Relating to sound, the science of sound, or a sense of hearing.

Annual Fuel Utilization Efficiency. A measurement used to rate furnace efficiencies by dividing the ratio of heat output by heat input.

American Gas Association, Inc.

A device that changes humidity levels, temperature or quality of air.

Measured in cubic feet per minute (cfm), this is the amount of air circulated in a space.

Parts of a system including the fan-blower, filter and housing.

Air Conditioning and Refrigeration Institute.