Questions & Answers for Reverse Cycle Air Conditioners

Function

• Reverse cycle air conditioners contain a valve not found on standard air conditioners. This valve allows the unit's condenser and evaporator to reverse places during the winter. To get cool air, the owner needs to turn this extra valve to a position where it permits hot gas to flow from the compressor to the condenser. When heat is necessary, the extra valve permits the compressor's hot refrigerant to access the unit's condenser. During this process, the condenser acts as the unit's heating coil.

Size and Efficiency

• The basis for a reverse cycle air conditioner's size is how many British thermal units (BTU) it removes per hour. A BTU is the amount of heat required to raise 1 pound of water through 1 degree Fahrenheit. An air conditioner replaces a building's BTU heat energy with cool outdoor air. Another sizing measurement for air conditioners is ton. One ton equals 12,000 BTUs per hour. Most reverse cycle air conditioning brands display the season energy efficiency ratings (SEER) on the unit. The SEER formula is the ratio of cooling output in terms of BTU per hour divided by unit's power consumption in watts per hour.

Availability

• Air-source, ductless mini-split, geothermal and absorption are the four types of reverse cycle air-conditioners available as of the fall of 2011. According to U.S. Department of Energy, the air-source model is the most common reverse cycle air conditioner. Air-source units transfer heat between a house and outside air via air ducts. They can trim electricity costs by up to 40 percent. Ductless mini-split is a variation of air-source units for homes with a duct system. Geothermal units, also known as ground-source or water source heat pumps, transfer heat between a house and a nearby water source or the ground. The absorption units are the only reverse cycle air conditioner to run on heat energy.

Cost

• A reverse cycle air conditioner's price varies depending on the unit's brand and size. Larger homes require larger sized units. A larger unit's size ranges between 48,000 to 60,000 BTUs per hour, or 4 to 5 tons. Also, the cost of reverse cycle air conditioners increase if they have a high SEER rating. The Goodman 17 SEER heat pump system, which is 5 tons, costs more than $6,100 as of 2011. The Ruud 13 SEER unit, which is 1.5 tons or 18,000 BTU's per hour, costs less than $2,300.