The most common way to heat and cool Atlanta area homes involves the pairing of a gas furnace with an air conditioner. Furnaces burn natural gas, liquid petroleum or oil to release energy and create heat. A flue is designed to remove harmful gases from the home as result of this combustion process. A circulation blower then draws air through duct work into the unit and after warming distributes through supply ducts into your home. The efficiency rating sometimes called AFUE can vary greatly along with operating expenses. Older units and duct work can waste over 50 cents of every dollar spent. A properly installed condensing furnace can easily pay for itself by bringing 95 cents of every gas dollar spent into your home.