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What Is a Geothermal Heat Pump? How Does It Work?

Geothermal Heat Pump

If you’ve been keeping up with new advances in HVAC technology, you’ve probably heard the terms “geothermal heat pump,” or “ground-source heat pump.” These are the same thing as one another, and a geothermal heat pump is touted as a renewable alternative to conventional gas boilers and other heating technology. But what exactly are geothermal heat pumps, and how do they work? Let’s find out.

divider 7Basic Information About Geothermal Heat Pumps

Geothermal heat pumps work by taking advantage of the Earth’s temperature. While the air’s temperature fluctuates wildly depending on the climate, the Earth’s temperature beneath is relatively stable. By using heat exchangers, a geothermal heat pump can draw the hot or cold energy from the Earth and use it to help heat or cool your home.

Many countries are encouraging citizens to switch to ground-source heat pumps to cut down on carbon emissions stemming from fossil fuel-based industries. Ground-source heat pumps are estimated to save somewhere around 3–4 times the energy of a typical air-source heat pump.

Over 5–10 years, the average consumer with a ground-source heat pump recoups their investment in energy savings due to the incredible efficiency of geothermal heat pumps.

Heat Pump Water Heater
Image Credit By: nikkytok, shutterstock

How Does It Work?

Geothermal heat pumps work with two parts: the geothermal heat pump itself, which usually sits in your house, and a series of underground pipes underneath your property.

First, the heat pump itself is installed where your boiler or other heating system was. Then, your property has to be excavated for long lengths of piping to be placed underground. This long and costly excavation step is the main barrier to entry for geothermal heat pumps, while air-source heat pumps are simple to install.

The pipes are filled with a water-based liquid solution, and then passively absorb the heat energy from the ground where they’re installed. These pipes send the captured heat energy to the heat pump, where it then uses heat exchanging technology to heat or cool the air.

More precisely, the newly piped-in air swaps temperatures with the liquid refrigerant in the pump. The resulting air is vaporized and compressed, then passed through a heat exchanger to increase the temperature. For cold air, the reverse is done.

Theoretically, a ground-source heat pump can produce up to four units of heat for every unit of heat it draws from the Earth. This makes them one of the most efficient and green HVAC systems to date.

What Are the Different Types of Heat Pumps?

There are three major types of heat pumps: geothermal (ground-source), air-source, and hydrothermal (water-source). All of them save energy compared to traditional HVAC systems, though each has unique benefits and drawbacks depending on your climate.

Air-source heat pumps are the most easily installed of the bunch, but they’re not as effective in extreme climates. In mild climates, air-source heat pumps are most effective, beating out their sister heat pumps in efficiency. In climates where the temperature regularly drops below freezing, a ground-source heat pump would be more effective.

Water-source heat pumps are perhaps the most uncommon type of heat pump because they require a large body of water. Wells, lakes, and rivers are all examples of where you could put a water-source heat pump. These pumps are more consistent because they use a constant flow of water to work. Unfortunately, water-source heat pumps can’t function as the sole HVAC system when the water source is frozen.

Water heater Pump
Image Credit: akiragiulia, Pixabay

Where Are Geothermal Heat Pumps Used?

Geothermal heat pumps can be used anywhere as long as there’s enough land to place the pipes, which makes them extremely versatile compared to, say, a water-source pump that has to be installed near water.

Ground-source heat pumps are especially useful in climates that regularly get below freezing. In freezing conditions, a water-source heat pump wouldn’t work, and an air-source heat pump would struggle. For the greatest efficiency, ground-source heat pumps are the best bet for cold climates.

These pumps can be used anywhere that air-source or water-source pumps can be installed, too, provided there’s enough land. Even in the same conditions, a geothermal heat pump is at least as efficient as either of the other types.

Advantages of Geothermal Heat Pumps

Geothermal heat pumps have some remarkable advantages that make them well worth using in virtually any climate. Here are a few noteworthy pros of ground-source heat pumps:

Pros
  • The most energy-efficient HVAC choice for very cold climates
  • Works anywhere there’s enough land to install loop system
  • Can produce up 3–4 times more heat or cool air than air-source heat pumps
  • Help reduce greenhouse gas emissions
  • Provides heat and cool air in all conditions
  • Long-term energy savings

Disadvantages of Geothermal Heat Pumps

While geothermal heat pumps are marvelous inventions that are sure to change the HVAC landscape in the future, they do have some marked disadvantages you need to be aware of before you invest in one for your home.

Cons
  • Costly and lengthy excavation required for installation
  • Requires enough land to place loop system, making it unsuitable for people who rent or don’t own their home
  • Open-loop systems can contaminate groundwater
  • Expensive to install upfront

electric heat pump

Frequently Asked Questions (FAQs)

How long do geothermal heat pumps last?

Your average ground-source heat pump lasts much longer than your typical boiler. Whereas the latter would only last 10–15 years before replacement or repair, a ground-source heat pump will last 20–25 years. This means that on top of saving on energy costs, you can save on maintenance costs too.

What maintenance do geothermal heat pumps need?

Unlike other systems that require yearly servicing, geothermal heat pumps can operate for years without servicing. The most you’ll need to do is replace the air filter every few months and call a qualified technician to give it a checkup every 5 years.

swim pool heater vs heat pump

Are there tax incentives for switching to a geothermal heat pump?

Yes! There’s currently a federal tax incentive for all geothermal heat pump systems installed in 2022. You can get reimbursed up to 26% if you install a geothermal heat pump in 2022, but this reimbursement reduces to 22% if you wait until 2023.

divider 7Conclusion

Geothermal heat pumps are a great new invention that helps heat and cool our homes without relying on fossil fuel-based energy sources. Even though they have a few disadvantages, ground-source heat pumps are still a great step in the right direction.


Featured Image Credit: Caifas, Shutterstock

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