Electric Heat Pumps: Utilizing Existing Technology for a More Energy-efficient Future

Home Improvement

On September 19, 2018, a resident of Saco, Maine, posing outside with his Fujitsu heat pump in the background. The average temperature in Saco, Maine, is 25.7 degrees F (-3.5 degrees C) in January and 69.9 degrees F (21.1 degrees C) in July. Shawn Patrick Ouellette/Portland Portland Press Herald via Getty Images

With the aim of reducing U.S. greenhouse gas emissions by 50-52 percent below 2005 levels by 2030, President Biden is taking steps to convert as many fossil fuel-powered activities to electricity and to generate that electricity from low-carbon and carbon-free sources like wind, solar, hydropower and nuclear energy.

Residential and commercial buildings account for a significant portion of energy consumption. In 2019, more than one-seventh of U.S. greenhouse gas emissions were caused by these buildings. New heating and cooling systems are crucial for achieving the target.

Fortunately, electric heat pumps are a technology that already exists and can help achieve the goal of reducing carbon emissions. These devices are three to four times more efficient than furnaces and can heat homes in winter and cool them in summer by transferring heat in and out of buildings without burning fossil fuels.

As a clean and renewable energy expert, I am focused on studying energy use in housing and understanding how slowing climate change will impact industrialized and developing countries. I believe that using clean and renewable electricity to power buildings is an essential strategy that will not only help the environment but also save consumers money.

Heat Pumps Work by Moving Heat, Not Air

Most heating systems in the U.S. rely on forced-air furnaces powered by natural gas, electricity or heating oil. These systems burn fuel or use electricity to heat air, which is then blown through ducts into individual rooms.

A heat pump operates differently, similar to a refrigerator that extracts energy from the air inside and releases that energy into the room, cooling the interior. To heat a building, a heat pump extracts energy from outdoor air or the ground and converts it into heat for the house.

Here’s how it works: Cold fluid circulates through coils of tubing in the heat pump’s outdoor unit. The fluid absorbs heat energy from the surrounding air, which is warmer than the fluid. The fluid vaporizes and flows into a compressor. Compressing any gas generates heat, so this process produces heat. The vapor then moves through coils of tubing in the indoor unit of the heat pump, heating the building.

In summer, the heat pump operates in reverse, transferring heat from inside the room to the outdoors, even though the outside temperature is hotter – essentially, functioning like a larger version of a refrigerator.

More Efficient Than Furnaces

Heat pumps require a small amount of electricity to operate. Modern heat pump systems can transfer three to four times more thermal energy in the form of heat than they consume in electrical energy – and that the homeowner pays for – to complete the work.

The conventional heating systems waste some amount of energy while converting it from one form to another. Whether it is burning oil or gas to heat air in a furnace or using electric heaters to heat air, the waste occurs when the electricity is generated. The production of electricity at a power plant results in the loss of about two-thirds of the energy used. Retrofitting residential and commercial buildings with heat pumps increases heating efficiency and further lowers energy use and carbon emissions when combined with a switch from fossil fuels to renewables.

There is a growing restriction on fossil fuel use and proactive policies that are driving sales of heat pumps in the U.S. and internationally. Heat pumps are currently used in 5 percent of heating systems worldwide, but that share needs to increase to one-third by 2030 and much higher after to reach net-zero emissions by 2050. Heat pumps are cheaper to run than furnaces in warmer areas with relatively low heating demands. Tax credits, utility rebates, or other subsidies can provide incentives to help with up-front costs, including federal incentives reinstated by the Biden administration.

In extremely cold climates, heat pump systems have an extra internal heater to help out, which is not as efficient and can significantly run up electric bills. People who live in cold locations may want to consider geothermal heat pumps as an alternative. Geothermal systems collect warmth from the earth and use the same fluid and compressor technology as air source heat pumps to transfer heat into buildings. They cost more since installing them involves excavation to bury tubing below ground, but they also reduce electricity use.

New, smaller “mini-split” heat pump systems work well in all but the coldest climates. These systems connect to wall-mounted units that heat or cool individual rooms, eliminating the need for ducts to move air through buildings. They are easy to install and can be selectively used in individual apartments, making retrofitting large buildings easier. Even with the best heating and cooling systems, installing proper insulation and sealing building leaks are key to reducing energy use.

For help in figuring out whether a heat pump can work for you, your electricity provider can be a good source of information. Many utilities offer home energy audits that can identify cost-effective ways to make your home more energy-efficient. Other good sources include the U.S. Department of Energy and the American Council for an Energy Efficient Economy. Heat pumps are ready to play a central role as the push to electrify society gains speed.

FAQ

1. What is an electric heat pump?

An electric heat pump is a heating and cooling system that moves heat from one location to another using electricity. It can be used to heat or cool a home, and it is more energy efficient than traditional heating and cooling systems.

2. How does an electric heat pump work?

An electric heat pump works by transferring heat from the outside air or ground to the inside of a building. It does this by using a refrigerant that absorbs heat from the outside and releases it inside. In the summer, the process is reversed, and the heat pump removes heat from the inside and releases it outside.

3. What are the benefits of using an electric heat pump?

Electric heat pumps are more energy efficient than traditional heating and cooling systems, which can save homeowners money on their energy bills. They are also more environmentally friendly, as they produce less greenhouse gas emissions than traditional systems. Additionally, electric heat pumps can be used for both heating and cooling, providing a year-round solution for home comfort.

4. Are there different types of electric heat pumps?

Yes, there are several different types of electric heat pumps, including air-source, ground-source, and water-source heat pumps. Air-source heat pumps are the most common and use the outside air as the heat source. Ground-source heat pumps use the ground as a heat source, and water-source heat pumps use water as the heat source.

5. Is it expensive to install an electric heat pump?

The cost of installing an electric heat pump can vary depending on several factors, including the type of heat pump, the size of the home, and the location. However, over time, the energy savings from using an electric heat pump can offset the installation costs.

6. Can an electric heat pump be used in cold climates?

Yes, electric heat pumps can be used in cold climates, but they may not be as efficient as they are in milder climates. In colder temperatures, the heat pump may need to use more energy to transfer heat from the outside to the inside of the home.

7. How often does an electric heat pump need maintenance?

An electric heat pump should be inspected and serviced annually by a qualified HVAC technician. This can help ensure that the system is running efficiently and prevent any potential problems before they occur.

8. How long does an electric heat pump last?

An electric heat pump can last for up to 15 years or more with proper maintenance and care. However, the lifespan of the system can vary depending on the type of heat pump and how often it is used.

9. Can an electric heat pump be used with solar panels?

Yes, an electric heat pump can be used with solar panels to further reduce energy costs and increase the system’s environmental friendliness. The solar panels can provide the electricity needed to power the heat pump, reducing the need for grid-based electricity.

10. Are there any government incentives for installing an electric heat pump?

Yes, there are several government incentives available for homeowners who install electric heat pumps, including tax credits and rebates. These incentives can help offset the installation costs and make the switch to a more energy-efficient system more affordable.

11. Can an electric heat pump be used in conjunction with a traditional heating system?

Yes, an electric heat pump can be used in conjunction with a traditional heating system, such as a furnace. This can provide a backup heat source in case the heat pump is not able to keep up with the heating demand.

12. How can I determine if an electric heat pump is right for my home?

To determine if an electric heat pump is right for your home, you should consult with a qualified HVAC technician. They can evaluate your home’s heating and cooling needs and recommend the best system for your specific situation.