Central air conditioning not only adds to our general comfort it is also helpful in maintaining a healthy indoor air quality by reducing humidity and the likelihood of mold and mildew. Central air conditioning systems are practically invisible, they are convenient to operate and unlike most wall units, they are whisper quiet.

Central air conditioning is, of necessity, a split system, with some components installed outdoors and other parts located indoors. The heaviest, noisiest, heat-shedding components, the compressor and condenser coil, are installed outdoors, while the evaporator coil (fan blower unit) is installed indoors, normally in the loft or ceiling area. Then the central air conditioning runs the air throughout the entire house with the use of ducts. A thermostat controls the temperatures of the house by measuring a sample of the return air (air returning to the indoor unit).

Installing central air conditioning in your home has many benefits. One of the primary benefits is the cost of energy. How you check the efficiency of a unit is by reading and comparing the SEER rating (SEER - Seasonal Energy Efficiency Ratio).

Central air conditioning systems and air-to-air heat pumps are required to have a SEER rating of 12.0 or higher. Central air conditioning uses a considerable amount of electricity, particularly in warmer climates, and is one of the most expensive home appliances to operate in summer but is one of the most energy efficient forms of heating available to the consumer.

You may have heard about a rebate that purchasers may be eligible for when buying certain A/C systems. Central air conditioning units that qualify for a rebate must have a SEER rating of 15.0 or greater. Your air conditioning salesperson, contractor or service technician can provide that information and will most likely use it as a selling point.

Units with an EER of 9.0 or above are considered very efficient. To help you compare units, a range for competing air room conditioners of the same cooling capacity is printed on the Energy Guide label below the EER. All of these details are there for the consumer so they can make informed decisions. Use it to your advantage.

SEER takes into account the startup and shutdown time as well, making it a more accurate measurement for determining the actual energy costs for the end user. SEER is used with central air conditioning, while EER is used with room air conditioners. For new central systems, SEERs of 12 or higher are generally considered high-efficiency units.