Product brands 7sons HVAC 2016 Full Line Carrier corporation residential 1 to 5 tons of cooling and up to 155,ooo BTU heating.  Light commercial up to 25 tons cooling 300,ooo BTU heating .              Product styles for Homes are called ! split HVAC systems which the HVAC condenser is located outside the home usually side of home or back of home with the heating unit and indoor refrigerant cased coil as one inside the home with duct work to them known as main supply duct and return ducts.                                                                              Product style 2 is called  Package unit where the HVAC heating and air conditioning unit is one called self contained unit usually found in mobile homes the other is commercial application located on the roof of the establishment.                                                                            Product source of energy used for establishment is called  oil, natural gas, propane or electric heat which uses heating elements located in the indoor unit to provide heat in your home similar to a oven in your home. The other most common is called electric heat pump system which provides both heating and cooling not using oil, gas, propane. Product efficiency ratings   the yellow sticker found on all appliances. seer ratings yellow sticker (seer) seasonal energy efficiency ratio. equipment installed along with properly installed duct work to match the cubic feet of area to remove heat or cool the total space, known as heating and cooling calculation for the building. older equipment seer ratings verses today new standards in many can be upgraded equipment and duct work at minimal investment cost.