An air conditioning system can vary by the particular brand. That being said, here are some of the common components you will run into.

A true air conditioning system performs three basic functions. The one that would first occur to anyone entering an air conditioned room from the outside during the summer is air cooling. The lowering of the temperature of the air is one of the basic characteristics of an air conditioning system. Cooling capacity is measured, strangely enough, in a heating measurement, the BTU. A BTU is a British Thermal Unit which is the amount of energy needed to raise the temperature of one pound of water one degree of temperature measured in Fahrenheit.

The efficiency of an air conditioning unit can be measured by a standard known as SEER rating. SEER stands for Seasonal Energy Efficiency Rating. The minimum SEER rating has been 10, but recently was raised to 13 in January of 2006. The SEER is defined as the total annual BTU output of the unit defined by its energy input. The Federal Government and the Department of Energy have regulated the required SEER of all new air conditioning units in an attempt to reduce energy consumption.

High efficiency in cooling is more critical in climates where annual temperatures are higher and the demand for air conditioning is greater. It is actually worse to have a unit that is too large for the size of the building being cooled. An oversized unit not only costs more than it should, but runs efficiently. It will also not run long enough to properly dehumidify the air.

The ability to remove moisture from the ambient air is another characteristic of an air conditioner. Humidity is often as important to comfort as air temperature. High humidity also can contribute to health problems and contributes to mold growth in the duct work of the system and in the home itself. A regular refrigerant type air conditioner removes moisture from the air by condensation as the moist air passes over the cooling coils. The process is similar to what happens when you have a glass of cold liquid on a hot, humid day. Just as water will condense out of the air on the outside of the glass, it condenses on the tubing of the cooling coils. The condensed moisture drips off the pipes and is removed by a drain in the duct work.

Air filtering is the third characteristic of an air conditioner. Filtering is done by passing the air intake flow through a filter that removes dust and lint. Some filters can be used that remove microscopic pollutants from the air. The filters need to be changed on a frequent basis as a clogged filter greatly reduces the efficiency of the unit. Cooling, dehumidifying, and filtering are all characteristics of a good system, and produce air that is comfortable, dry, and clean.

Quinton Williams is with AirConditioningRepairCompanies.com - a directory of air conditioning repair companies as the name suggests.