Getting information on adding heat pump

Where may I obtain some information on air-to-air heat pumps? Ross Kingon Glen Mills, Pa.

I suggest you drop a note to the Air-Conditioning and Refrigeration Institute , 1815 North Fort Meyer Drive, Arlington, VA 22209, and ask for a free copy of the booklet "Heat, Cool, and Save Energy with a Heat Pump."

You might also ask for any other pamphlets or booklets on heat-pump systems, including air to air. In this way you can get a fairly thorough discussion of what a heat pump is designed to do and what it cannot do. In some situations it may not be the way to go.

The modern heat pump is actually traced to a young French engineer who, in the early 1800s, described the principles of a device he said would be the most efficient way to produce heat energy.

The engineer, Sadi Carnot, Sketched out an idea for a reverse heat-engine cycle that is very much what the heat pump of today does.

Essentially, a heat pump extracts the heat from the outside air or water in the winter and expels it indoors. In the cooling mode, it takes the heat out of the house and pumps it outside, just like any air conditioner.

A heat pump can be either a self-contained system or, on the other hand, include some of the equivalent indoors and the rest outside.

While a supplemental heat source is required where the winter temperature falls toward or below freezing, the heat pump alone can do the job for much of the year.