Overview. Central heating differs frome heating in that the heat generation occurs in one place, such as a furnace room or ba.t in a house or a mechanical room in a large building though not necessarily at the geometri.y “central” point ..Central air conditioning not only lowers temperatures throughout a house, it dehumidifies and filters the air, leaving it cleaner and more comfortable to breathe..Prices by Unit Size. The table below represents the different size Rheem central air units available for the most common home installations. The cooling area is an estimate, based on the average size area it will cool..AC Units Direct, online Homeowner’s resource for Goodman ac units wholesale central air conditioning, heating ac unit equipment, wholesale hvac parts. We carry Heat Pump, Central Air Conditioners, and high efficient Gas Furnaces from Goodman, Rheem, Carrier, Trane..