November 2, 2023
an You Have a Heat Pump and a Furnace?

Here in Las Vegas, NV, people assume that air conditioning is the only HVAC concern that a homeowner can have. However, it does get cold enough here in the winter that reliable heat is important, too. That’s one of the reasons that heat pumps are so popular here. They represent a single system that can give you heating and cooling at efficiency levels other HVAC systems can’t match.

Historically, however, heat pumps have had a weakness. It’s that they lose a great deal of efficiency when outside temperatures drop below freezing. Worse still, on very cold days and nights, they might struggle to deliver enough heat for your home. As a result, homeowners always ask us if they can have a heat pump and a furnace at the same time. Here’s a bit about why heat pumps struggle in the cold and whether you can pair one with a furnace for some heating security in the winter.

Why Do Heat Pumps Struggle in the Winter?

To understand why heat pumps can struggle in the winter, you must understand a bit about how they work. As their name implies, heat pumps move heat from place to place. However, they don’t create the heat they move. In the winter, a heat pump relies on heat energy in the outdoor air as a heat source for your home.

Heat pumps work based on the principle that there’s always heat energy in the air, even at very cold temperatures. That holds true down to absolute zero, or –459.67 degrees Fahrenheit. However, the colder the air temperature gets, the less heat energy remains and the harder it is to collect. So that’s the main reason why heat pumps start to struggle on very cold days.

Heat Pump vs. Furnace Efficiency

Under optimal conditions, an air-source heat pump can operate at efficiencies approaching 400%. By comparison, the most efficient gas furnace on the market is only 98.5% efficient. However, optimal conditions don’t include a decent part of the winters here in Las Vegas.

Most heat pumps begin losing efficiency as the temperature drops below 40 degrees Fahrenheit. At those temperatures, they can still provide ample heat for your home. But when the temperature reaches 25 or fewer degrees Fahrenheit, heat pumps become less efficient than the average gas furnace. That means they will start to cost more to operate than a comparable furnace and won’t deliver the same level of comfort.

It’s worth pointing out two things, however. One is that the vast majority of heat pumps on the market today operate quite well at below-freezing temperatures. There are even models that work well down to -15 degrees Fahrenheit! The other thing is that all heat pumps feature backup heat supply systems that turn on to augment the heat they provide when the temperature gets too low. This means owners of any modern heat pump shouldn’t ever have to worry about not having enough heat.

Most heat pumps feature electric resistance heating elements to perform this critical function. And since electricity is typically more expensive than natural gas, your heating costs will rise every time those backup heating elements turn on. And that is the reason that so many homeowners inquire about having a furnace and a heat pump at the same time.

So, Can You Have a Furnace and a Heat Pump at the Same Time?

There are three different ways that you can have and use a heat pump and a furnace at the same time in your home. The first is to leave your existing furnace and its thermostat as-is and install a heat pump with separate controls. In that setup, you’d need to manually turn each system on and off depending on your needs and comfort preferences. This used to be a very common solution for homeowners who were nervous about relying on a heat pump alone in the winter. However, this option has generally fallen out of favor of late.

The next way that you can have a heat pump and a furnace at the same time is to install a heat pump that’s compatible with your existing furnace. This is possible because a heat pump integrates into a furnace in the same way a central air conditioning system would. However, since the heat pump can also supply heat, your furnace’s control system would need a way to figure out which system to use at any given time. Plus, the evaporator coil inside your indoor unit would need to be capable of supporting the more efficient heat pump. Many existing furnaces won’t allow you this option.

Finally, you could opt for something called a dual-fuel heat pump system. It wouldn’t reuse your existing furnace, however. Instead, it’s a heat pump with a built-in gas-fired heating element. The system would have built-in circuitry to decide when the gas burner would produce heat more efficiently than the heat pump. It would then activate the burner as needed. In this way, you would always have a reliable source of heat that operates at peak energy efficiency, no matter the temperature outside.

Is a Furnace Necessary With a Heat Pump?

These days, it rarely makes sense to keep a gas furnace alongside a heat pump. This is due to the advancing technology of today’s heat pumps, in addition to the realities of energy costs. There aren’t enough extremely cold days to make the cost of running electric resistance heating elements occasionally that expensive. Then, when you consider that you’ll have to pay base costs for your home’s natural gas line even when you are not using it, the advantages disappear completely.

In reality, there’s only one reason why you might want a gas furnace as a backup heat source — air temperature. A gas furnace produces hot air that ranges in temperature from around 140 to 170 degrees Fahrenheit. However, the average heat pump will only provide hot air that’s around 100 degrees, even when it’s about 40 degrees outside. And when the outdoor temperature drops, so does the temperature of the air the heat pump provides.

As a result, homeowners used to the extremely hot air of a gas furnace often feel like a heat pump produces a drafty feeling by comparison. It’s something that new heat pump owners adjust to over time. But if you’d prefer the option of having very hot air available on the coldest nights, you might want to preserve a gas furnace as an option.

Your Home Heating Experts

The good news is that, whether you want a heat pump, a furnace, or both, BEST Air Conditioning Plumbing Repair can help. We’ve served the Las Vegas area since 2016, offering the latest in HVAC technology, and HVAC installation, repair, and maintenance services. We also offer comprehensive plumbing services, indoor air quality, and duct sealing, too. We even offer financing on approved credit if you need some help fitting a new HVAC system into your budget.

For heat pumps, furnaces, and your other home heating needs, contact BEST Air Conditioning Plumbing Repair today!

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