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Why Are Furnaces Today More Energy Efficient?

Technology improves with each year, and this applies to gas furnaces as much as it does to computers and smart phones. Although gas furnaces have been around for a long time, they have undergone many improvements to make them both safer and more effective.

One area where gas furnaces have seen a tremendous enhancement is in energy efficiency, i.e. how well a furnace converts its energy source into actual heating power. At one time, the average furnace would only convert 60% of its fuel into thermal energy, wasting 40%. But today, most furnaces waste less than 20%, and there are special high-efficiency furnaces that only waste 3%. This is one of the reasons you should consider replacing an aged furnace (15–20 years old or more), even if it’s still working at providing your house with heat. You could save large amounts on your monthly heating bills with a newer furnace.

Reasons furnaces are more energy efficient

What’s behind the increased energy efficiency of modern gas furnaces? There are a number of reasons. One is the change from standing pilot lights to electronic ignition systems. A pilot light that has to burn all through the winter season in order to ignite the burners drains additional fuel. An electronic ignition system, however, only uses energy when the burners need to come on.

Sealed combustion chambers, which are a part of all high-efficiency furnaces, also contribute to lowering the amount of heat lost when a furnace runs. A sealed combustion chamber has the additional advantage of improving safety.

High-efficiency furnaces known as condensing furnaces use a second heat exchanger to draw more thermal energy out of the combustion gases that generate heat in the first exchanger. Instead of exhausting the vapor from the first exchanger out of a vent, it goes to the second exchanger, where through a process of condensation, more heat is extracted.

Finally, many furnaces today have multi-stage burners and variable-speed blower fans. This means the furnace doesn’t always have to operate at the same high energy level when it comes on, but can lower its power output to conserve energy while still delivering the appropriate level of heat.

Ask our technicians at Purl’s Sheet Metal & Air Conditioning in Madera, CA about your options for an energy-saving new furnace installation or furnace replacement.

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