What Are the Differences? Heat Pumps vs. Furnaces

Most homeowners don't know the differences between heat pumps and furnaces. Understanding what the two are and how they work helps you decide on which you'd like to install in your home. Heat pumps and furnaces work to accomplish a similar goal. They are used to heat homes; however, they use different methods to achieve this.

The two systems differ in many ways, including their energy efficiency, heating capabilities, cost, use of space, maintenance requirements, etc. However, the main difference between the two is how they operate. Typically, furnaces heat your home using combustion and heat distribution, while heat pumps extract heat from the outside air and redistribute it through your home, regardless of outside temperatures.

Your preference for heating systems depends on several factors, including heat output and energy efficiency. However, the most common deciding factor is often the climate. For instance, most people in south Georgia or Florida prefer heat pumps because such regions don't get cold long enough to warrant homeowners to invest in furnaces.

Often, those that live in colder northern parts of the US are more likely to install furnaces because of the long cold temperatures. Additionally, you are more likely to find furnaces in older homes or those with easy access to natural gas. Let's dive in and learn more about furnaces, heat pumps, and their differences.

What's a heat pump?

Unlike furnaces, heat pumps don't generate heat. Instead, heat pumps extract heat from the outside air and transfer it inside, slowly warming your home. Heat pumps can extract heat from the outside air even when the temperature is below zero. However, they are marginally effective.

Heat pumps can be equated to reverse refrigerators. Refrigerators work by transferring heat from inside the refrigerator and moving it outside. This helps keep the food inside the fridge warm. This process is similar to how heat pumps cool down your home in the summer. The system does the exact opposite thing in the winter.

Additionally, heat pumps work as air conditioning units and can be used to cool your home in warm weather. Heat pumps extract heat from your home and dispel it outside during the summer, leaving your home cooler than it was. The system uses the reverse valve, a simple component to regulate where heat is absorbed and dispelled.

Heat pumps work following three simple steps. For starters, they force warm air from outdoors or indoors through a series of coils filled with a refrigerant, i.e., pressurized ammonia gas. Heat pumps transfer heat from outside air to the desired location depending on the airflow direction.

Depending on the valve's setting, the refrigerant cools down or warms up, which heats or cools down your home, eliminating the necessity for different cooling and heating systems. Heat pumps don't require any types of fossil fuels to work. This makes them less expensive to run and more energy efficient. However, they are best suited for regions that don't experience wide outdoor temperature changes.

You may wonder why we don't use heat pumps throughout and forget about furnaces. However, as mentioned before, heat pumps don't generate heat. Instead, they transfer heat between different regions. Their efficiency depends on temperature differences and environmental heat, making them somewhat unreliable in extremely cold regions.

What is a furnace?

Furnaces rely on a fan and either natural gas, electric heaters, or oil to heat your home. The fuel source is ignited in a combustion chamber, and the air is blown through it. The heated air is distributed throughout your home with a fan through your ductwork. Cooler air displaced in homes is redirected through return vents and forced through the furnace, making it warmer.

This cycle is repeated until the desired temperature is achieved. Furnaces blow much warmer air than heat pumps because they use flames to create heat. According to the Department of Energy, furnaces are a more popular heating source for residential areas in the US. Furnaces have fewer mechanical parts making them easier to maintain than heat pumps and have a longer lifespan. They are less energy efficient and ideal for individuals that want warmer air or have access to natural gas.

Technological advancements have made furnaces more energy efficient over the years; however, individuals that have furnaces may have to install an air conditioning unit to cool the house during warm seasons. Furnaces are essential in regions that experience extremely cold temperatures.

While they are costly to run, they are quite efficient at warming homes during harsh winters. Homes that experience harsh winters and use heat pumps to keep warm often rely on other heating appliances like radiators and space heaters.

Let's move on to the differences between furnaces and heat pumps now that you understand what they are.

Differences between Heat Pumps and Furnaces

Operation

Furnaces generate heat by burning gas or oil, while heat pumps draw heat from outside your home using electricity. Due to their functioning, heat pumps generate less heat than furnaces. Thus, they work best for homes in warmer climates, i.e., zones 1, 2 and 3 on the climate zone map (Department of Energy).

That said, heat pumps are more versatile for indoor comfort since they can keep homes heated during cold seasons and cool during warmer seasons. Furnaces lack this multi-function feature. Furnaces are designed to produce heat. Thus, homeowners that want to cool their homes during warmer seasons are forced to install a separate air conditioning system.

While both systems provide different functionalities, some climates allow homeowners to install a dual fuel system that incorporates the furnace and heat pump for cooling and heating and provides greater savings. The best example would be pairing an air source heat pump and a gas furnace.

Individuals that install such a system get more energy-efficient results since it gauges the outdoor temperature and determines the most efficient option for heating your home. The only drawback of such a system would be the installation costs.

Energy efficiency

Technically, heat pumps are more energy efficient than furnaces; however, gauging their efficiency and comparing the two systems is a bit complicated. Experts consider heat pumps more energy efficient than furnaces because they transfer more energy than they use. 

However, some highly efficient furnaces provide up to 98% energy efficiency. In perfect conditions, heat pump systems can transfer over 300% more energy than they use.

Additionally, heat pump systems are powered through electricity, meaning that you can make substantial savings on fuel consumption. Heat pumps have over 100% efficiency in various temperatures and climates; plus, you can use them as an air conditioner or heater.

Installing a heat pump system will cost you fewer energy expenses than a furnace.

Maintenance

Typically, furnaces and heat pumps will operate better and last longer with efficient, preventative maintenance. Both systems use air filters that owners can replace easily. Typical heat pumps (for residential areas) have indoor and outdoor units that should be inspected and cleaned yearly.

Gas furnaces don't require outdoor units; however, they are often paired with central air conditioning units. These units require maintenance; however, their uniqueness makes it hard to specify how you should maintain them and how often they should be done. You'll have to contact your carrier expert for information on how often you should conduct a proper service.

Space

Heat pumps require a 24" clearance and are installed outdoors, while furnaces require about a 30" clearance space and are installed indoors. Traditional air source heat pumps require indoor air handler units called fan coils.

Installation cost

Installation costs for heat pumps and furnaces depend on your home's current system setup and compatibility. For instance, some homes lack access to natural gas. In such cases, installing a furnace and air conditioner is more expensive than a heat pump system.

Also, homes that don't have wiring for supplemental heating common with heat pump systems may incur extra costs when setting up the system. Your dealer is the best person to provide information on which of the two systems will best suit your needs.

Effectiveness in cold weather

Gas furnaces burn fuel to generate energy making them more effective in cold weather than heat pumps since they rely on extracting heat from the environment. The more outside air falls below freezing point, the more unreliable heat pumps get. You could use supplementary heating systems to keep warm; however, these are more costly.

It will make more sense to use furnaces if you live in very cold regions since they produce more heat quicker than heat pumps. Heat pumps are better for individuals that live in regions that are moderately warm and experience a small shift in temperature during cold seasons.

Comfort

Air generated by heat pumps isn't quite as hot as that which you'd get from gas furnaces. Some people don't like the cooler air and prefer quickly warming their home to their preferred temperature. Additionally, the air produced by heat pumps is more humid and won't dry your skin like hot air produced by a furnace would.

Conclusion

Heat pumps and furnaces have lots of differences and various pros and cons. However, the differences don't make one system better than the other. They work well in their designated regions and should be used as such. Remember, using your heat pump in cold areas and vice versa could cost you more than you a lot more in the long run.