When an air conditioner is turned on, electrical power is used to cool a gas in a coil to its liquid state. Warm air in your home is cooled by contact with the cooling coil, and this cooled air is channeled to the rooms of your home through ducts and out registers or -- in the case of room air conditioners -- directly from the unit itself.All heating and cooling units burn fuel. Air conditioners use electricity. Most home heating systems use gas or fuel oil; other systems use electricity. The heat pump -- an electrically powered climate control unit -- both heats and cools air. In summer it extracts heat from the air inside your home. In winter it pulls heat from the air outside and uses this heat to warm the air inside.
