Frequently Asked Question
What is the difference between a standard efficiency furnace and a high-efficiency furnace?
Standard efficiency units transfer less heat to the airstream than their high-efficiency counterparts. As a result, more heat exhausts through the flue. Because of these hotter flue temperatures, standard efficiency units have to be vented with metal flue piping, while high-efficiency furnaces can use PVC flue venting. High-efficiency units gain their extra efficiency, by adding a secondary heat exchanger that allows for greater heat transfer to the airstream. Standard efficiency units are typically referred to as 80% units, meaning that 80% of the heat generated from the fuel being burned, is transferred to the airstream. High-efficiency units can range anywhere from 90% to 97.5% efficient at transferring heat to the airstream.