Power, efficiency and reliability are the main features of a good furnace. A good furnace keeps a home comfortable and warm, is low on running and maintenance costs, and lasts for a long time while performing at its peak.
The Annual Fuel Utilization Efficiency of a furnace measures its overall energy performance. A good furnace has a high efficiency rate, ideally around 90 percent. Additionally, furnaces with multi-stage heating reduce temperature swings by maintaining consistent heating levels. These furnaces turn off specific burners when complete furnace output is not required.
Furnaces that have variable speed technology rather than continuous fan mode reduce energy consumption. A dual heat exchanger is another feature of a good furnace, using a secondary heat exchanger to capture excess and release heat instead of wasting it.
A good furnace is not noisy. Most high quality furnaces include insulation in the enclosed burners and in the blower section to keep sound levels to the minimum. An electronically commutated motor is another feature that aids in silent operation. Intelligent controls and thermostats that allow heat control and air flow indicate a good furnace. Other valuable features include pressure switches, heat exchangers that reduce corrosion, induced draft blowers and direct-drive blower units.