High Efficiency Gas Furnace

A high-efficiency gas furnace is an air heating unit fired with natural gas or propane that has high efficiency of at least 95%. These furnaces use condensing technology to wring out all the heat possible from the exhaust gases.

Look for Energy Star labels, and efficiency ratings greater than 95%. Efficiency is rated as Annual Fuel Utilization Efficiency (AFUE). Furnaces contain air filters that need to be cleaned or replaced periodically. Be sure to check the manufacturer's instructions and keep a record of furnace maintenance.

By using 6% less gas than a standard model, a high-efficiency furnace can reduces your energy bills and your greenhouse gas emissions. However, it is important to note that even high-efficiency gas furnaces are inefficient compared to other heating systems types such as ground or air sourced heat pumps.

High-efficiency condensing furnaces are so efficient, capturing so much of the heat of combustion, that their flue gas is low enough temperature to go out through a plastic pipe without melting it. It's amazing to think of a combustion appliance with a plastic chimney!