Glossary

The ability of a heating or cooling system to cool or heat a given amount of space. For heating, this is usually expressed in BTU's. For cooling, it is often given in tons.

A burner that acquires all air for combustion from outside the heated space.

A instrument that uses fuel to support combustion.

Air Conditioning & Refrigeration Institute.

British thermal units per hour. 12,000 BTUh equals one ton of cooling.

British thermal unit. The standard of measurement used to guage the amount of heat required to raise the temperature of one pound of water by one degree (Fahrenheit).

American Society of Heating, Refrigeration and Air Conditioning Engineer

A piece of machinery that removes unwanted particles from moving air.

The portion of the central air conditioning or heat pump system that moves cooled or heated air throughout a home's ductwork. In some systems a furnace will handle this function.

The amount of air the system circulates through your home, indicated in cubic feet per minute (cfm). Correct airflow depends on the indoor unit, the ductwork, the outdoor unit, and even whether the filters are clean.