Everyone’s heard of high efficiency furnaces, but does anyone know what makes them so much better? First of all, a high-efficiency furnace understands how to use the gas more efficiently. They measure this efficiency with the AFUE rating which stands for the Annual Fuel Utilization Efficiency rating. The Department of Energy calls any unit with an AFUE of 90% or higher, a high-efficiency furnace. Our experts here at Getzschman compiled a list of improvements that make these furnaces more effective than others:
High Efficiency-Furnaces Improvements
- Combustion Fuel: This is how the air mixes with the fuel. High-efficiency models feature “sealed combustion” which mixes the air with the fuel at a controlled rate in order to maximize the heat from the fuel.
- Condensing Gas Furnaces: Exhaust gases run through a second heat exchanger to remove and use all available heat that would otherwise be exhausted. This allows them to pull out nearly all of the heat and only leave behind the condensed water that is drained off.
- Two Stage Gas Valve: Gas valves have also seen improvement. This two stage gas valve will quickly heat up the furnace while dropping to more of an energy conserving flow.
- Variable Speed Motors: This will help save on electricity. Instead of the furnace going on and blasting the home with hot air for a short time and then turning off, variable speed motors run the blower for longer periods at lower speeds. Not only does it use less energy, it‘s quieter and your home stays more comfortable.
- Electronic Spark Ignition: This takes place of a pilot light that is constantly on, the electronic spark ignition fires the furnace on demand.
The top-of-the-line models are the most efficient and can interact with a thermostat and adjust furnace output and blower speed accordingly. Some models are up to 98.2% efficient.