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What Are the Ratings for Furnace Efficiency?

When you are buying a new furnace, energy efficiency is an important consideration. Furnaces with higher efficiency ratings will use less energy to heat your home, and cost you less money. Lower rated furnaces need more energy to produce the same amount of heat, which will result in higher utility bills.

Less Energy Lost Equals Higher Efficiency

Furnace efficiency is determined using the Annual Fuel Utilization Efficiency (AFUE) rating. The AFUE refers to the percentage of the total energy a furnaces uses that actually becomes heat energy. For example, a furnace with an AFUE rating of 90 transforms 90 percent of the energy it uses into heat energy for your home, while 10 percent of the energy is lost. The less energy lost, the more efficient the furnace. The highest possible AFUE rating is 100, which would mean that a furnace converts every bit of the energy it uses into heat energy. Older, low-efficiency furnaces may have efficiency ratings than range between 56 and 70, while new furnaces rarely have AFUE ratings below 80. The mot efficient models currently in production may achieve 98.5 percent efficiency.

Minimum Efficiency Requirements

The Department of Energy now requires relatively high efficiency ratings for many styles of newly manufactured furnaces. Non-condensing furnaces—which tend to be less efficient than condensing furnaces—must now meet a minimum AFUE rating of 78. Non-weatherized gas furnaces must have an AFUE rating of 80 or higher, while weatherized furnaces must have ratings of 81 or higher.

Protect Your Home From Heat Loss

An extremely efficient furnace is not enough to ensure that you are heating your home efficiently. Heat preservation is also important for overall energy efficiency and lower energy bills. A large percentage of heat energy can be lost through duct work if vulnerable areas are not insulated effectively. Ducts that run through attics, basements and crawl spaces are often responsible for heat loss—sometimes as much as 35 percent of your total heat energy. Such a large amount of heat loss in your home can completely offset the gains of an efficient furnace. Losing around 30 percent of the heat that reaches your home is equivalent of having and old and extremely inefficient furnace instead of a new, efficient model. Addressing exposed duct work and other areas of your home where heat may be lost is critical for improving your home’s overall energy efficiency. Thank you for reading! To learn more about high-efficiency furnaces, or improving your home’s heating efficiency, please call today to speak to one of our experienced technicians.