What is a Dual Fuel System? What are the Benefits?

A dual fuel system is a heating system that utilizes a heat pump to heat your home when the temperature is 30 degrees or warmer, and a furnace that kicks on to heat your home when the outside temperature dips below 30.

A dual fuel system is a great option for homeowners in colder climates (like Pittsburgh) that want the efficiency of a heat pump and the comfort of a furnace.

Totally clear on what a dual fuel system is? We didn’t think so. Below, we’ll dive into more details regarding exactly what a dual fuel system is as well as:

  1. The ins-and-outs of how a dual fuel system works
  2. The benefits of a dual fuel system

Think a dual fuel system would be a great idea for your home? Contact our team of pros! We’d be happy to take a look at your home and current system to help you determine if a dual fuel system is a good option for your home. Learn more about the heating services we offer or…

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How does a dual fuel system work?

As we mentioned above, a dual fuel system is a combination of a heat pump and a furnace. A dual fuel system works by heating your home via a heat pump when the temperature outside is higher than about 30 degrees, and a furnace when the temperature is lower than 30 degrees.


Heat pumps work best when outdoor temperatures are above 30 and below 60 degrees. The reason is because heat pumps don’t create heat, but rather warm your home by transferring outside heat into your home. A heat pump does this by absorbing heat in outdoor air via refrigerant lines, bringing that heat inside, and heating your home’s air with it.

Refrigerant lines transfer heat from your outdoor unit inside (in heating mode).

However, when the temperature outside drops below 30 degrees, heat pumps have trouble drawing in enough warmth from the outside air to properly heat your home.

At this point, your dual fuel system would switch over to its backup heating method: the furnace.

Instead of using heat transfer to heat your home, furnaces actually create heat with fuel (gas or electricity). So, regardless of the outside temperature, a furnace should be able to adequately heat your home.

Now that you have a better understanding of how a dual fuel system works, let’s look at the benefits of a dual fuel system (why a homeowner would want to invest in 2 heating systems rather than just one).

Benefits of a dual fuel system

Here’s the bottom line: a dual fuel system is both the most efficientandeffective way to heat your home.

As we mentioned above, heat pumps warm your home by transferring heat from outside to inside. They don’t use fuel to create heat, they simply move heat from one place to another.

And because they don’t use fuel, heat pumps are the most efficient type of heating system (which means lower heating bills for you). However, as we also mentioned above, heat pumps don’t work very well in very cold climates (below 30 degrees), which is common for Pittsburgh winters.

So to save money but also stay comfortable in your home, you need a backup heating system, which, in the case of a dual fuel system, is a furnace. Furnaces are less efficient than heat pumps, but they can sufficiently heat your home regardless of the temperature outside, making furnaces a more effective way to heat your home.

All in all, a dual fuel system allows you to save money by using a heat pump when the temperature is moderate but also allows you to stay comfortable in your home via a furnace when winter temperatures drop below 30 degrees.

Ready to install a dual fuel system in your Pittsburgh home? Hire Calfo

Whether you’re sure you want a dual fuel system or you’re still trying to decide if it’s the best solution for your home, we’re here to help. We have years of experience helping Pittsburgh homeowners with their heating solutions and we’d be happy to help you too.