What is a Dual Fuel System?
We have written articles about heat pumps that included information on dual fuel systems, but we decided we wanted to dig a little deeper into this for our customers, especially with the rising energy costs we’re all facing now. So, let’s get to it!
What do we mean when we say, ‘dual fuel’? Great question: we in the industry forget that this isn’t widely known to everyone. A dual fuel system comes about when we pair a heat pump outdoor unit with a gas furnace inside the home. The heat pump will serve as the primary heating and cooling source for the home as it provides both, but that gas furnace will kick in when temperatures drop, and the heat pump is outside of its efficiency range and can’t keep up.
To explain how this saves energy, we need to give some attention to a standard electric heat pump system. These systems pair a heat pump outdoor unit with an electric air handler inside that is used for back-up heat. These units heat with straight electric coils ranging from 5kw to 20kw on average. That’s a lot of electricity being used to heat the home when your heat pump can’t keep up! The downside is that most homeowners don’t notice this back-up heat is running until they get their electric bill and it’s sky-high.
So now you can see how that gas furnace back-up can be beneficial. These systems are great for those who want to keep costs down but ensure comfort in colder weather. If anything goes wrong with the heat pump and you have a long wait time before a heating contractor can get out to fix things, that gas furnace is less expensive to run than straight electric heat and puts no additional stress on the power grid.
Recently at a dealer meeting we attended, a woman from an electric utility board was discussing the electric grid over the next decade. With the electrification movement, everyone has been encouraged to switch to electric vehicles, electric appliances, and yes, encouraged to ditch their gas and go for electricity. I won’t get into the fossil fuel debate, nor how electricity isn’t immune from using said fossil fuels here, but she showed compelling research showing that by 2030, we will not be able to sustain the power grid without brown outs or scheduled outages at the current electrification growth rate. She in fact suggested to us that we start selling more dual fuel systems to help offset this extra load during peak heating months.
So here we are! In some cases, this can save homeowners money by simply adding a heat pump to their existing gas furnace instead of tearing everything out and going all electric. This also gives homeowners a unique level of control over their energy use. If electric bills skyrocket in the winter, a dual fuel system will allow anyone to shut off the heat pump and use straight gas heat to warm their home.
Those handy whole-house generators? There is much less of a strain on power usage with your generator if you heat with a gas furnace vs. having to factor in 15kw straight electric heat on the off chance that it will be running when the power is out.
If you’re thinking about a new system or even just adding air conditioning to your existing gas furnace, ask your contractor to quote you a dual fuel system or a heat pump add-on. It really is the best of both worlds!
