airconditioner

An air conditioner cools indoor spaces by removing heat and moisture from the air and transferring it outside. It can be central, cooling multiple rooms through ducts, or a standalone unit such as a window unit, a portable unit, or a split system with an outdoor condenser and an indoor air handler. Key components include refrigerant, a compressor, evaporator and condenser coils, and an expansion device.

Most systems operate on the vapor-compression cycle: refrigerant absorbs heat at the indoor coil, is compressed to raise its temperature, then releases heat at the outdoor coil as it condenses. A thermostat controls the cycle, turning the compressor on and off to maintain the desired temperature. An indoor blower or fan circulates air through the evaporator.

Types include window units for single rooms, split systems with indoor and outdoor components, central systems with ductwork, and portable or ductless mini-splits. Heat pumps are a related technology that provide cooling in warm seasons and heating in cold seasons.

Efficiency is measured by SEER or EER; higher values indicate lower operating costs. Energy Star labels indicate models meeting efficiency criteria. Refrigerants have changed for environmental reasons; older R-22 is being phased out, while newer common refrigerants include R-410A and lower-GWP options such as R-32.

Sizing and installation should be performed by qualified professionals. Regular maintenance includes filter replacement, coil cleaning, checking for refrigerant leaks, and maintaining clear outdoor airflow and proper condensate drainage.

Air conditioners improve comfort and can aid air quality when paired with filtration, but they do not remove all pollutants and can distribute allergens if not maintained. In very cold climates, cooling-only units require a separate heating source or use a heat pump.