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Serving Orange County

- SINCE 1981 -

Serving Orange County

- SINCE 1981 -


Hours: Monday-Friday 7:30-5:30PM
Saturday: 8:00-1:00PM


Saddleback Plumbing Heating & Air Blog

The Truth About Electric Furnace and Gas Furnace Efficiency Ratings

twenty-dollar-bill-foldedFall is the usual time for homeowners to make changes in their central heating systems. Even in sunny Orange County, where the only snow we see is on the distant peaks, a central heating system is necessary for homes that often get drafty on the winter nights. Sometimes the upgrade for a heater is to buy a new one.

If you’re home is like most, you use a furnace for central heating. The two common types of furnaces people use are natural gas furnaces and electric furnaces. You might not face a choice about which type of have—if you don’t have a natural gas line, you definitely won’t get a natural gas furnace! But when you do have to make a choice, be careful that you don’t make the mistake about furnace efficiency ratings that has often misled customers into making the poorer system choice.

AFUE Is the Efficiency Rating for a Furnace

When searching for a new furnace installation in Rancho Santa Margarita, CA, one of the important stats to look at is AFUE, Annual Fuel Utilization Efficiency. AFUE is listed as a percentage; this is the percentage of the energy source the furnace converts into heating power. Anything left over is lost to exhaust. For example, an older mid-efficiency furnace with an AFUE of 80% loses 20% of the combustion gas it burns to exhaust, while the remaining 80% becomes heat sent into the air. The higher the AFUE, the more efficiently the furnace uses energy.

Electric Furnace AFUE Rating

What’s the average AFUE rating for an electric furnace? There is no range—the AFUE is always 100%!

But there is more to the story. The important fact to know is that AFUE doesn’t guarantee savings on utility bills! It measures how efficiently a furnace uses its energy source, but not the cost to run the furnace.

The reason electric furnaces all have 100% AFUE is because there is no exhaust with electrical resistance heating. All the electric power sent through the heating elements of the furnace is used to directly heat the air. None of the electricity goes to waste. However, electric furnaces almost always cost more to run than natural gas furnaces. The reason for this is the cost of electricity compared to natural gas; electricity costs more, and a furnace must draw on enormous amounts of it to properly warm a home.

Another Electric Option

In general, we recommend homes with a gas connection stick with using a gas furnace and not switch to electric. There are many new furnace options with higher efficiency than your current one, and making this switch can lead to savings. (Provided you have professionals handle the installation.)

If you have an all-electric house, you don’t necessarily have to settle for an electric furnace. If you are also considering replacing your old air conditioning system, we advise you look into a heat pump installation. A heat pump is both an AC and an electrically powered heater that costs much less to run than an electric furnace.

Saddleback Plumbing Heating & Air has proudly served Orange County since 1981. Trust us with your heating replacement needs.

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