What Is a Heat Pump and How Does It Work?

Whether you’re looking to heat a new addition to your home or just want to reduce your reliance on gas-powered systems, an electric-powered heat pump can provide a compelling primary or supplemental heating option. So, what is a heat pump, and how does it work? A heat pump system is a single-unit alternative to a traditional HVAC system. Learn more about what a heat pump is and what makes it an ideal heating system.

What Is a Heat Pump, and How Is It Used?

A heat pump provides both heating and cooling to your home and is available as either a ducted or ductless system. Electricity powers a heat pump, so it increases your home’s energy efficiency without fossil fuel dependency. Heat pumps work best in less extreme climates (typically those that don’t drop below freezing in the winter) and offer a low-maintenance, money-saving option for heating your home.

Heat pumps run on a refrigerant that transfers heat. They work similarly to air conditioners, but heat pumps can reverse the process to heating mode and also warm your home. To warm your home, a heat pump intakes warm air, pulling the heat from the ground or air outside. To cool your home, the pump pulls heat from inside and transfers it outside.

Parts of a Heat Pump

Heat pumps feature five key parts that work together to either transfer heat or change the pressure of the refrigerant, resulting in either heating or cooling:

• Indoor unit: The indoor unit has a fan and coil. The coil functions two ways: either as an evaporator or a condenser. After the heat transfers between the inside air and refrigerant, the fan circulates the air throughout your home.

• Outdoor unit: This part of the heat pump contains a fan and refrigerant coil; heat transfers between the outside air and refrigerant.

• Compressor: The compressor pressurizes and heats the refrigerant like an air conditioner compressor.

• Expansion valve: The expansion valve depressurizes and cools the refrigerant.

• Reversing valve: This valve helps you switch between heating and cooling by reversing the cycle.

Types of Heat Pumps

When considering different types of heat pumps, you should consider your current heating and cooling setup, the space available for an installation, and the heat pump's intended purpose.

Air-Source Heat Pump System

This heat pump is one of the easier types to install and is also the most common heat pump. The air-source heat pump has two parts—an indoor air handler unit and an outdoor heat pump unit—that process air as it passes between the parts. During the processing, the two units absorb and release heat.

Pros of Air-Source Heat Pumps

• Typically less expensive to install than ground-source heat pumps

• Relatively simple to maintain and repair

• Can also work as an air conditioner in the summer

• No need for a separate heating and cooling system

Cons of Air-Source Heat Pumps

• Efficiency can decrease in very cold climates

• Relies on outdoor air temperature, which can fluctuate

Mini-Split Heat Pump System

This is another air-source heat pump; however, it’s different because it’s a ductless version. It functions similarly to the standard air-source heat pump system but doesn’t require ductwork to distribute the air. It works well for home designs that don’t have ducts or require smaller retrofit options.

Pros of Mini-Split Heat Pumps

• Highly efficient and cost-effective for heating and cooling individual rooms or zones

• Provides flexibility for customized temperature control in different areas of a building 

• Easy to install without the need for ductwork

• Typically quieter than most traditional types of HVAC systems

Cons of Mini-Split Heat Pumps

• Higher up-front costs compared to traditional heating and cooling options for the same amount of space

• May require professional installation, especially for larger or multi-zone systems

• Multiple indoor units may affect the aesthetics of the space

• Regular maintenance is necessary for optimal performance and longevity

Ground-Source (or Geothermal) Heat Pump System

Also known as a geothermal heat pump, this type of heat pump pulls heat from the ground to help heat your home during the cooler months. Then, when the season changes and you need cooling, the ground-source pump cools the air before distributing it into your home.

Pros of Ground-Source Heat Pumps

• More energy efficient in extreme climates

• Longer life span compared to air-source heat pumps

• Uses the naturally stable underground temperatures of the earth

Cons of Ground-Source Heat Pumps

• Higher installation costs

• Requires more space for installation, such as a large yard or drilling for a vertical loop system

• Not a DIY-friendly installation

Hybrid Heat Pump Systems

Also called dual fuel systems, hybrid heat pumps combine a heat pump with an additional heating source, such as a furnace or boiler. When temperatures fall below a certain level, the system automatically switches to the furnace or boiler. This setup is perfect for regions with consistently low temperatures below freezing and is compatible with both air-source and ground-source heat pumps.

Pros of Hybrid Heat Pumps

• Ensures consistent heating capabilities

• Efficient in both moderate and extremely cold climates

• Reduces the need for fossil fuels

• Provides flexibility and versatility in heating options

Cons of Hybrid Heat Pumps

• Higher up-front cost compared to traditional heating systems

• Typically require professional installation and maintenance

• Additional components may require more space for installation

• Requires a backup heating system

How Much Does a Heat Pump Cost?

Heat pumps can range in cost and are impacted by the type, installation materials, and your home’s design, square footage, and existing HVAC. The average heat pump cost ranges from $4,250 to $7,950. Once installed, yearly tuneups cost around $50 to $180. You can also expect to spend about $150 to $600 to hire a local heat pump repair pro.

Pros and Cons of a Heat Pump

Heat pumps might not be the right choice for every home since they have more requirements up front for installation and power. However, for a home with the right setup, heat pumps can be worth it, offering savings, efficiency, and dependability.

Pros

Heat pumps offer some significant benefits. Here’s how their pros stack up:

• More energy efficiency: Because a heat pump transfers heat rather than generating it, it’s a more energy-efficient system. Heat pumps can reduce your household dependency on fossil fuels by running on electricity, equating to lower carbon emissions by 46% to 54%, according to a study by the Natural Resources Defense Council (NRDC). It may also be compatible with solar- or wind-powered energy.

• Dependable heating: Heat pumps are a good heating choice for homes that don’t experience extreme winters, offering better humidity control and air quality than a traditional system. A heat pump also has a quieter operating system and removes the risk of a gas leak (since it’s electrically powered).

Cons

Here are a few of the top heat pump drawbacks:

• Difficult to install: While a heat pump may be lower maintenance than a traditional furnace in the long run, it requires a more complex installation. For geothermal heat pumps, the installation requires outside groundwork a certain distance from your home, which may be harder to retrofit.

• Upfront expenses: Higher installation costs may be a factor, especially for a geothermal unit. The labor to install the heat pump may vary depending on the complexity, amount of prep work, and installation time.

If you’re unsure whether your home would experience more of the pros or cons with a heat pump, you can consult a heat pump installer near you for more details and an evaluation.