Furnace Efficiency Ratings: Important Numbers to Understand

When you’re in the market for a new heating system for your Northeast Ohio home, the most important consideration you make likely will be furnace efficiency ratings. All central heating and cooling equipment must carry ratings that let consumers know how efficiently the system uses energy. In the case of combustion furnaces, the ratings are called AFUE, short for annual fuel utilization efficiency

The rating is expressed as the percentage of the fuel that the furnace uses to heat your home, versus the amount that’s wasted. All the fuel going into the furnace is used, but not all goes into heating your home’s air. Some of it goes up the chimneyFurnace Efficiency Ratings: One of the Most Important Numbers to Understand as water vapor and combustion gases, and the amount of heat that’s lost factors into the efficiency rating.

In the U.S., the minimum AFUE for a combustion furnace is 78 percent, which means the system wastes 22 percent of the fuel it uses. In a colder climate like ours, that’s a significant loss of fuel, but new furnaces are available with furnace efficiency ratings as high as 98 percent. Furnaces that reach such high efficiency levels are condensing furnaces that extract nearly all the heat that they create.

These furnaces have a second heat exchanger that takes the heat from the water vapor that gas creates as it burns, and uses it to heat your home. The water vapor condenses and drains into your home’s plumbing. They cost more than a less efficient heating system, but over time with our long heating seasons, you’ll save money because you’re consuming so much less fuel.

The electricity the furnace consumes is not factored into the AFUE, but when you’re comparing systems, it’s a good idea to keep that in mind, as well. Furnaces with variable-speed motors in the blower use less electricity, regardless of their AFUE rating. As with any HVAC equipment, you’ll want to find a model that has the Energy Star seal of approval. For furnaces, that means an AFUE of at least 90 percent.

To learn more about furnace efficiency ratings and heating your home efficiently, please contact us at Geisel Heating, Air Conditioning & Plumbing. We’ve provided top-notch HVAC services for Cleveland area homeowners for more than 75 years.

Our goal is to help educate our customers in Cleveland, Ohio about energy and home comfort issues (specific to HVAC systems).  For more information about furnace efficiency ratings and other HVAC topics, download our free Home Comfort Resource guide.

For those Do it Yourselfers who would rather take control of your own indoor comfort, you can shop our online store for replacement parts, products and accessories!

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