The term “Air Conditioning” refers to the cooling and dehumidifying of indoor air for thermal comfort. In a broader sense, the term can refer to any form of cooling, heating, ventilation or disinfection that modifies the condition of air.

An air conditioner is an appliance, system, or mechanism designed to stabilize the air temperature and humidity within an area (used for cooling as well as heating, typically using a refrigeration cycle but sometimes using evaporation, most commonly used for comfort cooling in buildings and motor vehicles.

"Cooling Capacity"

Manufacturers produce air conditioners in a variety of sizes, typically measured in "tons" or "BTUs per hour."

A BTU British Thermal Unit is a common unit used for measuring heat output, equal to the amount of energy required to change the temperature of one pound of water one degree Fahrenheit. One ton equals 12,000 BTUs/hour-a term derived from the amount of energy required to melt 1 ton of ice in a day.

With air conditioners, bigger is not better. For one thing, the larger the capacity, the more a unit will cost; output is directly related to cost. Also, it's critically important to pick a size that is appropriate for the house.

An air conditioner that is too small can't keep up with load requirements on a particularly hot day. One that is too large will cycle off and on too frequently, doing a poor job of dehumidifying the air, which degrades comfort. In fact, it's better to slightly undersize an air conditioner than to oversize it.

Also, the air flow into and out of rooms must be carefully balanced to ensure efficient operation of the system.

These factors, as well as how well a house is insulated, how it's used by your family, the climate and more must be taken into account when selecting and designing your system. That's why you should consult a qualified air conditioning contractor.