Central air conditioners remove heat and dehumidify, or take away moisture from the air. They have air filters for removing dust and other particles. Warm indoor air passes over a very cold coil that removes the heat and moisture. Lowering the humidity level makes the air temperature more comfortable. Moisture removed from the air collects in a pan underneath the indoor coil, and is sent to a house drain. The unit’s blower circulates the air, while refrigerant inside the coil cools it, and the outdoor compressor transfers heat from inside the home to the outside.