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AFUE: The Only 4 Letters You Need To Save Money in Delco This Winter


It’s easy: Just look for the AFUE rating

 Annual fuel utilization efficiency (AFUE) is the universal measurement of furnace or boiler efficiency. All new furnaces and boilers are required by the Federal Trade Commission to display their AFUE rating on the product packaging so that consumers can make educated decisions, compare heating efficiencies of different models, and get the most bang for their buck. AFUE is a measure of how energy-efficient a furnace or boiler is at converting fuel to heat over the course of a year.

AFUE is the ratio of annual heat generated by the furnace or boiler compared to the total annual energy it had to consume to create that much heat. For example, a furnace with an AFUE of 90% means that 90% of the energy in the fuel used by the furnace becomes heat for the home while the remaining 10% escapes. AFUE doesn’t factor in energy loss due to duct systems or piping, which can account for as much as 35% of the furnace’s energy output, especially when ducts are located in partially conditioned or unconditioned space like the attic, garage, or crawlspace.

These days, most American homes stay warm in the winter with either furnaces or boilers. Furnaces heat air and then distribute it through the house using ducts. Boilers provide either hot water or steam for heating. Of the two options, steam boilers operate at a higher temperature than hot water boilers and are inherently less efficient, but nearly all manufacturers today offer multiple high-efficiency models of both furnaces and boilers.

One of the benefits of an all-electric furnace or boiler is that both carry no risk of energy loss through either the flue or chimney. The AFUE rating for an all-electric furnace or boiler is generally between 95% and 100%! The lower values are attributed to outdoor units because they have greater jacket heat loss. Despite their high-efficiency levels, the expensive nature of electricity around the country makes all-electric furnaces or boilers pretty unappealing to the discerning consumer.

The Department of Energy has set the minimum allowed AFUE rating for furnaces and boilers at 78%. In the future, minimum AFUE requirements for furnaces will be based on the type of fuel consumed (gas, oil, or electricity), whether the unit is weatherized or not, and whether the unit is designed for use in a mobile home.

Call the heating experts at Feehan today to schedule an installation for your very own high-efficiency furnace!

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