How Do Ground Source Heat Pumps Work?

Ground source heat pumps are a great option if you’re shopping for a heating system that doesn’t rely on harmful fossil fuel or you’re considering a A-rated gas boiler but want to see what your options are, we’re here to help.

So, how do ground source heat pumps work? These systems can lower your carbon emissions by using electricity and renewable energy to effectively heat your home.

They are one of many emerging technologies that are helping homeowners cut down on gas usage.

When shopping for a heating system that uses renewable energy, you’ll come across things like ground source heat pumps, air source heat pumps, or electric boilers powered by solar panels.

What is a Ground Source Heat Pump?

Let’s start by looking at what exactly a ground source heat pump is.

(If you want to learn more about boilers for your home and compare quotes, click here!)

In this article, we’re focusing on the ground source heat pump. Let’s unpack what exactly these systems are and how they work, so you can become a ground source heat pump expert.

A ground source heat pump, sometimes called a geothermal heat pump, is a heating system that draws out natural heat from the ground outside your home to provide heating and cooling. 

These systems function similarly to a traditional gas boiler heating system, but utilise electricity and heat from the ground, rather than the burning of fossil fuels, to create heat.

How Do Ground Source Heat Pumps Work?

The way your heating system works will vary depending on the specific type of geothermal heat pump system you purchase. Below, we’ll outline the general process for a closed loop system.

A geothermal heating system works to heat your home with a network of pipes buried in the ground outside of your home. Throughout the day, natural sunlight will warm the ground, all the way to the soil. In fact, even during colder times of the year, the ground temperature will stay at a decently warm temperature (around 10 degrees Celsius) about two meters down.

The looped pipe system, which is filled with a mixture of water and antifreeze, moves through the pipes and into a heat exchanger inside of your home. Here, energy captured from the heat in the ground can be turned into a gas, thanks to the refrigerant in the system.

This gas can then move into the system’s compressor, which can cause it to rise to your set temperature. After this, the heat can be sent to your home’s radiators, ducts, or to the underfloor heating system, depending on how you’ve set up your geothermal system. This is how it works to heat your home. Energy can also be distributed to your water system, so you can have hot water for baths, showers, and your taps.

The system can also do this process in reverse to cool your home, extracting heat from the air inside your home, carrying it into the system, and depositing it into the ground outside. This means a ground source heat pump system can work to replace gas space heating, water heaters, and your air conditioner.

Types of Ground Source Heat Pump Systems

As we touched on above, there are different variations of the geothermal heat pump. Let’s briefly outline the different kinds of systems you’ll see on the market.

Horizontal and Vertical Closed Loop Systems

A closed loop geothermal heat pump is the most common iteration. These systems have looping tube systems that are buried underground, connected to a system with a compressor and heat exchanger. After drawing on ground heat, the system converts the heat energy into a gas that can be used to heat your home and water.

A closed loop system will have either horizontal or vertical looping pipe systems. A horizontal pipe system is cost-effective and ideal for residential homes. Here, the piping layers are a few meters deep across a wide area of ground somewhere on your property. Due to this design, a horizontal loop system will require a significant amount of land to bury pipes outside the home.

In contrast, a vertical pipe system is ideal for larger commercial buildings, or in situations where there is not enough land for wide, looping pipes. Instead, piping will be less wide but go deeper into the ground, vertically. They are great options if you have minimal land for installation.

There are also pond/lake versions of the geothermal heat pump system. If you have a body of water close to your home, you can run the looping system underwater, rather than underground, and achieve a similar effect.

Ground Source Heat Pump Components

Let’s take a look at the different elements that make a geothermal heat pump work. You can expect to see the following as a part of your system:

• Ground Loop: The ground loop is a system of pipes that will either be buried underground outside of your property or placed in a lake or pond near the home. These pipes work to move the water and antifreeze mixture that either brings heat into the home or distributes it into the ground, whether you are in heating mode or cooling mode.
• Evaporator: The evaporator will work to absorb heat from the fluid in the ground loop, turning it into a vapor that can be moved into the compressor.
• Compressor: This part of the system is responsible for raising or lowering the temperature of the gas in the system by increasing its pressure, getting it ready to circulate throughout the home.
• Condenser: The condenser in your geothermal system is the unit that is actually moving heat throughout the home. The heat can be moved to your home’s radiator, ducts, or underfloor heating.

Ground Source Heat Pump Costs

If you’re looking to invest in a ground source heat pump system, you’re probably curious about the cost. The cost of your system will depend on a number of factors.

Are you installing it in a small home or a business? What is the brand of your unit? Are you going for horizontal or vertical loops? What kind of work needs to be done to your property before digging up space for the loops?

Questions like these will all hold some weight when trying to determine cost. For this article, we’ll be looking at average costs for a ground source heat pump system for a 2 bedroom home in the UK.

If you want to go more in-depth when trying to understand these costs, you can learn more here.

Ground Source Heat Pump Purchasing and Installation

The largest cost you’ll be covering when investing in this system is the price of the unit itself, plus installation. Ground source heat pumps require pricier installation costs when compared to something like an air source heat pump system because so much work needs to be done to the ground outside of your home.

For the average system, you can expect to spend between £16,000 and £35,000 for home installation. This is the price for the system itself, as well as groundwork installation costs. Keep in mind that these prices could go even higher if you need to pair the system with a new underfloor heating system, or if your home requires radiator upgrades.

Ground Source Heat Pump Running Costs

The running costs of a ground source heat pump are where you’ll begin to see some decreases on your monthly bills. For the average small property, you can expect annual running costs between £540 and £700. These prices are a bit lower when compared to typical oil or natural gas heating, which can cost between £500-1,250 annually.

Are There Incentives for Ground Source Heat Pumps?

We know the pricing for these units can be shocking, but thankfully, there are some incentives that are here to help! There are many different incentives home and business owners in the UK can take advantage of when fitting their homes with new technologies.

When fitting your home with a ground source heat pump, you can take advantage of the Domestic Renewable Heat Incentive. There are also similar options for businesses, thanks to the Non-domestic Renewable Heat Incentive. These incentives can help both home and business owners outfit their spaces with these great systems.

Ground Source Heat Pump Pros and Cons

When trying to determine if a ground source heat pump is the right system for you, it’s a good idea to weigh the pros and cons. Here we break down some of the things that make these systems great, and some of their drawbacks.

Ground Source Heat Pump Pros

A ground source heat pump has some amazing benefits:

Energy Efficiency

Ground source heat pumps tend to be more energy efficient than other heating and cooling systems. For every single unit of electricity that your pump uses, you can receive 2-4 units of heat energy.

Cut Carbon Emissions

Since this system replaces gas and fossil fuel use with electricity, it can help you significantly cut down on your carbon emissions. Its environmental friendliness can become even better if you pair this system with sustainable energy sources, like wind or solar power. Pairing this system with renewable energy is perfect for those looking to build homes that are greener.

Long Life Span

A ground source heat pump system has a life span that can make the initial investment worth it. Where gas systems have 10-15-year lifespans, a ground source heat pump can last up to 20 years.

Works Year Round

Of the different kinds of heat pump systems one can invest in, the ground source heat pump is effective year-round, even in cold weather.

Those familiar with air source heat pumps know these systems can struggle in environments with extremely cold temperatures. This is because they need to draw in outdoor air for heat, but it’s difficult to draw heat from the air when it is below freezing.

Since a ground source heat pump is buried in the ground, it is not impacted by freezing air. Even in cold climates, the depth at which your system’s tubing is placed should remain stable, allowing it to provide warmth even in the cold.

All-in-One System

We also love that a ground source heat pump can serve multiple functions in your home. These units are effective at both heating and cooling, meaning they can take the place of both your gas boiler and air conditioning unit. This is especially beneficial to those building new homes, giving them a heat source and cool air source in one convenient system.

Ground Source Heat Pump Cons

Of course, there are some drawbacks to these systems. Here are some of the negatives to investing in a ground source heat pump.

High Costs

A geothermal system like this has some pretty high costs for both the unit and installation, due to the nature of the system. These units feature some impressive technologies that come at a price. They also require a lot of groundwork for their installation. This price tag can make this system inaccessible for some buyers.

Better for New Builds

The high price tag and the work needed for installation also make this system complicated to add to an existing home. Since these systems work best with things like underfloor heating and need groundwork outside for installation, they are much better suited for new builds. It can be complicated and expensive to do the work to retrofit one of these systems on an existing home.

Need Space

The other drawback to these systems is the amount of space needed for the network of looping tubes. As we touched on above, you need a significant amount of yard space to install one of these systems. This means it’s not super realistic for people who don’t have large properties.

Ground Source Heat Pump FAQ

These are the most frequently asked questions buyers have regarding ground source heat pump systems.

How much space do I need to install a geothermal heat pump?

A ground source heat pump requires more room than other heat pump systems. Thankfully, with both vertical and horizontal loop style systems, there are options for people depending on the amount of space you have.

The average horizontal ground source heat pump system with 600 meters of looping needs a space of around 700 square meters for installation, dug 50-150m deep into the ground. This size becomes much smaller for vertical systems but will require more depth.

Will a ground source heat pump save me money?

 A ground source heat pump can save you money annually on your monthly bills. These systems will have you switching from relying on natural gas to electricity for home heating and cooling. This will cause huge drops on the gas bill, but a bit of an uptick on electric bills. You can see savings between £540 and £700 annually.

Are ground source heat pumps expensive?

Yes, ground source heat pumps are expensive, especially when compared to other heat pumps like air source heat pumps. This is due to the extensive amounts of groundwork needed for installation, and the technology needed for the system to work.

Are ground source heat pumps better than air source heat pumps?

The answer to this question depends on your situation, as both these systems are suited to different kinds of homes, and individual user needs.

A ground source heat pump is an amazing heating and cooling solution for new builds that have the space to fit it into their homes. In comparison, air source heat pumps are a great addition to existing/smaller homes and can work well when paired with other heating and cooling systems in the house.

When shopping for a heat pump system, do your research to determine which system sounds best for you. Both are great options when looking for heating and cooling systems that utilize electricity instead of harmful gas.

Can I claim a renewable heat incentive when buying a ground source heat pump?

Yes, you can! Renewable heat incentives make it easy for homeowners and business owners to justify the costs of these expensive heating and cooling systems.

For those in the UK, you should look into applying for the Domestic Renewable Heat Incentive if you’re a homeowner or the Non-domestic Renewable Heat Incentive for your businesses/pubic property. These can help you put money towards the purchasing of all kinds of renewable energy products, even outside of ground source heat pumps.

Are there alternatives to a ground source heat pump?

There are many different systems homeowners can utilize to cool and heat their homes. If you are interested in heat pumps but ground source heat pumps aren’t for you, you could always explore air source heat pumps. These systems are less expensive than ground source heat pumps and have a much easier installation process.

We also recommend looking into different boiler systems as a way to heat your home. If you want to stick with systems that are good for the environment, exploring a hydrogen boiler system is something we recommend. These systems can give you all the benefits of a gas boiler system, all while using hydrogen instead of fossil fuel gas.

In Conclusion

A ground source heat pump is a great option for anyone building a new home that wants a high-quality, eco-friendly heating, and cooling solution. While high in price, these systems can last for many years, save you money, cut down on your carbon footprint, and effectively heat and cool your home.

Of course, we still recommend you explore all the options available, so you can pick a solution that works best for your home and your lifestyle. With proper research and time, you can pick a home heating solution that is good for the future, and good for you.