What are the differences between gas and electric furnaces?

In this article, we review gas and electric furnaces, how each type of furnace works, and some of the key differences between them. If you need a new furnace in your home and you’re trying to decide between natural gas and electric models, call our team for a free in-home estimate today.

Gas furnaces

Gas furnaces generate heat for your home by combusting fuel (natural gas) in a combustion chamber and then transferring that heat to air through a heat exchanger.

A technician inspects a gas furnace after installation.

A technician inspects a gas furnace after installation.

Understanding gas furnace efficiency

When it comes to energy efficiency, gas furnaces are relatively efficient at generating heat for your home. The efficiency of a gas furnace is measured by its Annual Fuel Utilization Efficiency (AFUE) score. AFUE is the measure of how much heat a furnace can pull from the gas as it combusts it. A gas furnace with 80% AFUE converts 80% of its fuel into heat, with 20% being lost in the exhaust. In other words, the higher the AFUE, the more efficient a furnace is, as it will use less gas to produce more heat.

Today’s furnaces have an efficiency floor of 78% AFUE, but many high-efficiency models are nearing 100% AFUE. For example, the Carrier Infinity® 98 Gas Furnace boasts a 98.5% AFUE score, making it one of the most efficient furnaces on the market today.

An important note before we move on: AFUE is less useful when comparing different types of systems. As we’ll review below, electric furnaces have 100% AFUE, but that doesn’t make them less expensive to run. The same thing goes for propane or oil.

A system for all seasons

Because they draw heating energy from natural gas and not electricity, many gas furnaces do not need excessive amounts of electricity to operate. This makes them ideal during power outages caused by storms since they can be run off of a backup generator in your home.

Electric furnaces

Electric furnaces work like a super-sized hair dryer or toaster. Electric current is run through heating elements, heating them up to high temperatures. Cold air is then forced through those elements, rapidly heating the air before it is pushed out through your air ducts to the living spaces of your home. This process continues until the air temperature in your home matches what your thermostat is set to.

More efficient, but costs more to run

On the surface, this feels like a paradox, right? How can an electric furnace with 100% AFUE cost more to run than a gas furnace with 93% AFUE? While electric furnaces are far more efficient at converting their energy source (electricity) into heat than other types of furnaces, this efficiency is counterbalanced by the market prices of each energy source. Natural gas is typically far less expensive than just electricity, so even the most efficient electric furnaces may be more expensive to run.

Of course, the exception to this rule applies to homes with electric-generating solar panels. By pairing an electric furnace with rooftop solar, you can defray some of the costs associated with heating your home in the winter.

No need to vent

Unlike their gas-burning cousins, electric furnaces do not need to expel combustion gases from the home via a flue pipe. This means that an electric furnace only needs to be connected to ductwork, allowing it to go in more places in your home.

No gas combustion also means that electric furnaces do not have a flame sensor, a heat exchanger, or other components found in a gas furnace. There’s no risk of a gas leak or a carbon monoxide leak, although such events are relatively rare in a gas furnace, as well.

Other types of furnaces

There are also furnaces fueled by propane and oil. While these furnaces—like electric furnaces—are often more efficient than gas furnaces, their fuel types are more expensive. If you’re considering either of these types of furnaces, be sure to talk to your local HVAC company about energy costs in your area and what you can expect to pay to heat your home in the winter.

Learn more about gas and electric furnaces

If you’re deciding between gas and electric furnaces, calling us is actually a good place to start. At King Heating, Cooling & Plumbing, we offer free in-home estimates on new systems. Our technicians can meet with you to review your home’s heating needs, and then help you find the right system for your house and your family. Contact us today to schedule your free in-home estimate.

Preventing frozen pipes in your Chicago area home this winter

Every year, every winter, thousands of Chicago-area homes and businesses fall victim to the same disaster: frozen pipes bursting, sending water flooding through the building. This causes a ton of property damage, and can ruin your holiday season. Preventing frozen pipes needs to be your top priority this winter.

In this blog, we’ll run through the best ways to prevent your pipes from freezing, both before winter and during it. To schedule a furnace tune-up or plumbing services with King, contact us online.

Preventing frozen pipes

Preventing frozen pipes in your home means scheduling heating maintenance and insulating pipes.Pipes freeze when the water within them is exposed to consistent, freezing temperatures for a sustained period of time. The most common cause of frozen pipes is your furnace breaking down in the middle of the night, causing the temperatures in your home to plummet.

Our first recommendation? Schedule a furnace tune-up in the fall with King.

With that out of the way, here are some other tips for protecting your pipes from the deep freeze.

Preventing frozen pipes before winter starts

  • Insulate your home properly by insulating unprotected pipes. Try not to leave any gaps during the process. If it’s unavoidable, use pipe sleeves. Seal the joints and the slits with tape if you have to.
  • Check your basement, attic, and crawlspaces for cracks or air leaks, and seal any you find. (This will also help make your home more energy-efficient!)
  • Have a contractor install heat cables that can be controlled with a thermostat. Follow the instructions given in the manual to ensure you install the ones meant for your pipes correctly. At the end of the season, unplug the cables to preserve energy.
  • Replace single-pane windows with storm windows or ones that are more energy-efficient.
  • Contact the team at King for a FREE plumbing inspection to examine your plumbing beforehand. We’ll tell you what can be done to ensure your pipes do not freeze during the chilly weather.

Preventing frozen pipes during the winter

When the coldest nights of the year arrive and the blizzard hovers over Chicago, follow these tips to further protect your home’s pipes:

  • Cut off the water supply to faucets and plumbing outside your home by closing the valves.
  • Make sure your garage doors are closed at all times to protect the pipes located there from the cold.
  • Keep your kitchen and bathroom cabinets open sometimes to allow warm air to circulate inside. The warmth will help keep the pipes from freezing over.
  • Allow pipes that are susceptible to the cold drip a little. This includes both hot and cold water pipes. This subtle water movement—even at the pace of a drip—makes it harder for the water to freeze.

Here are some more tips from The Chicago Tribune on how to avoid frozen pipes.

Here are long-term solutions for protecting your pipes

These probably aren’t things you’ll be able to do in the middle of a blizzard, and they’re above-and-beyond the DIY tips shared above. But, they’re a good idea for the Chicago homeowner who is interested in protecting their pipes, above all else.

Install fiberglass insulation

Installing fiberglass insulation is one of the best ways to ensure those pipes remain warm during the winter. Professional plumbers know how to install these without damaging your property. This includes examining the insulation requirements in your home’s crawl spaces, attic, basement, and other places that are hard to reach.

With this process, pipes that do not have adequate insulation will be insulated to keep them from freezing over once the cold weather hits.

Call King for plumbing repair and more advice on avoiding frozen pipes

As a company that provides both heating and plumbing services to the Chicago metro, King knows a thing or two about preventing frozen pipes. After all, we’ve been serving you for more than 45 years!

To schedule your furnace tune-up, your free plumbing inspection, or just talk through the state of your home’s pipes, contact us online.