|
 |
Electric Air-to-Air Heat Pumps
Electric air-to-air heat pumps are basically reversible air conditioners. They transfer heat from the air in one location to the air in another. In summer, they operate as air conditioners, transferring heat from the home. In winter, they reverse their operation, gathering heat from air outside the home and transferring it inside. Most heat pumps deliver conditioned air to the home using ductwork.
Since heat pumps transfer rather than generate heat, they can be extremely efficient, delivering more than three times as much heat as they consume in energy. In many parts of the country they are the least expensive way to heat and cool a home. Heat pumps have the additional advantages of providing heating and cooling in one unit using a single energy source. In addition, heat pumps do not require flues and avoid roof penetrations, and associated installations and labor costs.
Air source heat pump efficiency depends on outdoor temperature. In the heating mode, performance drops as the outside air temperature drops. In cold climates, these units require a supplemental heating system which operates during times when the unit cannot produce enough heat to maintain the desired indoor temperature. Electric resistance back-up is most common, but gas, oil, and LP gas back-up heating systems may also be used.
