Deciding whether to invest in a furnace when you already have a heat pump can be a difficult decision with many factors to consider. Determining the most efficient and cost-effective heating solution for your home is essential.

In this article, we will explore the reasons why you might need both a heat pump and a furnace, as well as the advantages and situations where having both can be beneficial.

Do I need a furnace if I have a heat pump?

Yes, you may still need a furnace even if you have a heat pump. A heat pump is an efficient heating and cooling system that works by transferring heat between indoors and outdoors. It can provide heating during mild to moderate weather conditions. However, in areas with extremely cold temperatures, a heat pump may struggle to extract enough heat from the outside air to adequately warm the indoors.

In such cases, a furnace can supplement the heat pump by providing additional heating power, ensuring comfort during colder periods. A furnace can also be used for heating purposes when the heat pump is undergoing maintenance or repairs.

7 reasons why you might need both a heat pump and a furnace

1. Supplementing heat pumps in extreme cold weather

In regions with very low temperatures, a heat pump may struggle to extract enough heat from the outside air to effectively warm the indoors. In such cases, a furnace can be used alongside the heat pump to provide additional heating power and ensure comfortable indoor temperatures during colder periods.

2. Dual fuel system for optimal efficiency

A dual-fuel system combines the benefits of a heat pump and a furnace to optimize energy efficiency. The heat pump operates as the primary heating source during moderate weather conditions, while the furnace takes over during extremely cold weather when the heat pump’s efficiency decreases. This combination allows you to enjoy energy-efficient heating throughout the year.

3. Backup heating during heat pump maintenance

When a heat pump requires maintenance or repairs, having a furnace as a backup can ensure that you still have a reliable heating system in place. This can prevent discomfort and inconvenience while the heat pump is being serviced.

4. Enhanced heating capacity

In larger homes or buildings with high heating demands, a heat pump alone may not provide sufficient heating capacity. By incorporating a furnace into the system, you can supplement the heat pump’s heating capacity and ensure consistent warmth throughout the entire space.

5. Fuel flexibility

Heat pumps rely on electricity to operate, while furnaces can be powered by various fuel sources such as natural gas, propane, or oil. Having both a heat pump and a furnace gives you the flexibility to choose the most cost-effective and readily available fuel source based on your specific needs and local availability.

6. Cooling capability

While primarily known for their heating function, some heat pumps also have cooling capabilities. However, in regions with extremely hot climates, a separate air conditioning system may be required for more efficient cooling. By combining a heat pump with a furnace, you can have both effective heating and cooling solutions tailored to your specific climate.

7. Zone heating and cooling

For homes with multiple zones or rooms that have different temperature requirements, having both a heat pump and a furnace allows for more precise zoning. You can use the heat pump in some areas and the furnace in others, providing individualized comfort control and potentially reducing energy consumption by only heating or cooling occupied spaces.

What advantages are there to having both a heat pump and a furnace?

1. Energy-efficient heating and cooling: Having both a heat pump and a furnace allows for optimal energy usage throughout the year. During moderate weather, the heat pump operates as the primary heating and cooling source, utilizing electricity to transfer heat. This results in energy savings compared to using a furnace alone. When extreme temperatures require additional heating or cooling power, the furnace can supplement the heat pump, ensuring comfort while still maintaining energy efficiency.
2. Cost-effective fuel options: By having both a heat pump and a furnace, you can take advantage of cost-effective fuel options. Heat pumps operate on electricity, which can be more affordable in certain regions. However, in areas with access to natural gas, propane, or oil, furnaces can be utilized when these fuel sources are more cost-effective. The flexibility of choosing between different fuels based on availability and pricing helps optimize cost savings.
3. Reliable backup system: In the event of maintenance or repair needs for either the heat pump or the furnace, having both systems provides a reliable backup. If one system is temporarily unavailable, the other can continue to provide heating or cooling comfort. This ensures that you are not left without a functioning system and minimizes potential disruptions or discomfort.
4. Enhanced heating capacity: In larger homes or buildings with high heating demands, relying solely on a heat pump may result in inadequate heating capacity. Incorporating a furnace into the system allows for increased heating power to meet the higher demands. This ensures consistent warmth throughout the entire space without overburdening the heat pump, leading to more efficient operation and potentially lower energy costs.
5. Zoning flexibility: With both a heat pump and a furnace, you have greater flexibility in zoning your home or building. Different areas or rooms can be heated or cooled individually by utilizing the heat pump in some zones and the furnace in others. This zoning capability enables personalized comfort control while minimizing energy waste by only conditioning occupied spaces.
6. Year-round comfort optimization: Combining a heat pump’s ability to provide efficient heating and cooling with a furnace’s supplemental heating power allows for year-round comfort optimization. The heat pump is effective in moderate climates, where its energy efficiency shines, while the furnace ensures comfort during extreme cold weather. This comprehensive solution covers all temperature ranges, providing continuous comfort throughout the year.
7. Future-proofing: By having both a heat pump and a furnace, you future-proof your home’s heating and cooling capabilities. As technology advances and new innovations emerge, you can adapt and upgrade either system without being limited to a single option. This flexibility allows you to take advantage of advancements in energy efficiency, improved performance, or eco-friendly features as they become available.

In what situation would I need both a heat pump and a furnace?

In regions with extremely cold climates, such as northern areas, a heat pump alone may struggle to extract enough heat from the outside air during frigid temperatures. In these situations, a furnace can supplement the heat pump’s heating capacity, ensuring sufficient warmth indoors.

For larger properties with high heating demands, a heat pump alone may not provide adequate heating capacity. Incorporating a furnace into the system allows for increased heating power, ensuring consistent warmth throughout the entire space.

In regions with fluctuating weather patterns or significant seasonal temperature variations, a dual-fuel system with both a heat pump and a furnace offers optimal efficiency. The heat pump can serve as the primary heating source during moderate weather conditions, while the furnace can take over during extreme cold spells. This combination maximizes energy efficiency and ensures comfort throughout the year.

What is a heat pump, and how does it work?

It works on the principle of moving heat rather than generating it. In simple terms, during hot weather, a heat pump acts as an air conditioner, extracting heat from inside your home and transferring it outside, cooling the indoor environment. Conversely, during cold weather, the heat pump reverses its operation, extracting heat from the outdoor air (even in cold temperatures) and transferring it indoors to warm your home.

What is a furnace, and how does it work?

A furnace is a heating system that generates heat by burning fuel, such as natural gas, propane, or oil. It works by igniting the fuel in a combustion chamber, creating a flame that heats up a metal heat exchanger.

As the heat exchanger becomes hot, a blower fan forces air over it, transferring the heat to the air. The warm air is then circulated through ducts and distributed to different rooms in your home through vents or registers. At the same time, the combustion gases produced during burning are safely vented out of your home through a flue or chimney.

How does a heat pump work in cold winters?

A heat pump is a heating and cooling system that operates by transferring heat between indoors and outdoors. It works in a similar way to a refrigerator, but in reverse. During warmer months, a heat pump extracts heat from indoors and releases it outside, providing cooling. However, in cold winters, the operation of a heat pump changes.

Instead of generating heat, it reverses its refrigeration cycle to extract heat from the outdoor air and transfer it inside. While the outdoor air may feel cold, it still contains heat energy. The heat pump absorbs this heat and uses it to warm the indoor space. Despite colder temperatures, a heat pump can efficiently extract heat from the outdoor air and provide comfortable heating during the winter months.

Why might a heat pump become less efficient in extreme cold?

First, as the outdoor temperature drops, the heat pump has to work harder to extract heat from the cold air. The temperature differential between the indoor and outdoor environments becomes larger, making it more challenging for the heat pump to transfer heat effectively.

Next, the refrigerant used in heat pumps becomes less efficient at colder temperatures, reducing its ability to absorb and release heat efficiently. Frost or ice buildup on the outdoor unit can further hinder the heat transfer process, requiring the heat pump to go through defrost cycles that temporarily interrupt heating.

Finally, the heat pump’s capacity decreases as outdoor temperatures drop, resulting in a reduced heating output. While modern heat pumps are designed to operate in cold climates, extreme cold can still impact their efficiency and performance, making supplemental heating from a furnace or other heating source necessary in these conditions.

How does a furnace work in cold winters?

When you adjust the thermostat to a higher temperature during cold winters, the furnace kicks into action. The fuel is ignited in the combustion chamber, producing a flame that heats up a metal heat exchanger. As the heat exchanger becomes hot, the blower fan forces air over it, transferring the heat to the air.

The now-warm air is then distributed through ductwork and delivered to different rooms in your home through vents or registers. At the same time, the combustion gases produced during the burning process are safely vented out of your home through a flue or chimney. The process repeats as needed, maintaining a comfortable indoor temperature throughout the cold winter months.

What does it mean to use a furnace as a backup for a heat pump?

This backup system comes into play during extreme cold weather conditions when the heat pump’s efficiency decreases due to lower outdoor temperatures. The furnace, which typically operates on natural gas, propane, or oil, can generate additional heat to supplement the heat pump’s heating capacity. By having a backup furnace, homeowners can ensure continuous and reliable heating even in the coldest periods.

This setup offers advantages such as improved comfort, as the supplemental heat from the furnace helps maintain desired indoor temperatures. It also provides peace of mind, knowing that if the heat pump requires maintenance or repairs, the furnace can step in and prevent any disruptions in heating.

Using a backup furnace can help optimize energy efficiency by allowing the heat pump to operate at its most efficient levels while utilizing the furnace only when necessary.

What are the energy efficiency differences between a heat pump and a furnace?

Heat pumps are known for their high energy efficiency, especially during moderate weather conditions. They work by transferring heat between indoors and outdoors, using electricity to move heat rather than generate it. This allows them to provide efficient heating and cooling throughout the year. However, as outdoor temperatures drop in extremely cold weather, the efficiency of a heat pump decreases as it requires more energy to extract heat from the colder air.

On the other hand, furnaces generate heat by burning fuels such as natural gas, propane, or oil. While furnaces can provide reliable heating even in the coldest temperatures, they are generally less energy-efficient compared to heat pumps.

What are heat strips, and how can they serve as a backup?

• Supplemental heating during extreme cold: Heat strips can provide additional heating power when the heat pump alone is unable to meet the heating demands during extremely cold weather. They serve as a backup by activating automatically when the heat pump struggles to extract enough heat from the outdoor air.
• Quick and responsive heating: Heat strips offer quick and responsive heating as they can generate warmth almost instantly. When activated, they produce heat rapidly, helping to raise the indoor temperature to the desired level promptly.
• Ensuring comfort during defrost cycles: Heat pumps occasionally go through defrost cycles to remove ice buildup from the outdoor unit. During this time, the heat pump temporarily stops providing heat. Heat strips can serve as a backup heat source during defrost cycles, ensuring continuous comfort and preventing temperature fluctuations in the indoor space.
• Supplementing heat pump maintenance or repairs: When a heat pump requires maintenance or repairs, it may be temporarily out of service. In such cases, heat strips can act as a backup heating option, providing warmth until the heat pump is back in operation.
• Energy-efficient operation: While heat strips are effective at providing supplemental heat, they are less energy-efficient compared to the heat pump itself. Therefore, use them judiciously and rely on the heat pump as the primary heating source whenever possible to maximize energy efficiency.