Compare ground source heat pumps

Welcome to SpotDif’s ultimate 2024 guide to ground source heat pumps, your essential tool for mastering home heating and cooling. Are you considering installing a ground source heat pump, looking to cut down on your energy expenses, or interested in making your home more environmentally sustainable? If so, this guide is designed specifically for you.

In this guide, we’ll explore the different types of ground source heat pumps available in the UK, including closed-loop, open-loop, and hybrid systems. Each type offers unique advantages suitable for various home environments. We’ll delve into how these systems work, the benefits they provide, and the key factors you should consider before making a decision.

From understanding the core principles of ground source heat pumps to comparing their respective costs and efficiency gains, our detailed overview will equip you with all the information you need. Ready to discover which ground source heat pump is the best fit for your home? Let’s dive in!

Heat pumps are systems that efficiently transfer heat from one location to another using minimal energy. They offer both heating and cooling solutions by moving heat between the air or ground and your home, making them a practical and versatile choice for year-round climate control.

Air Source Heat Pumps (ASHPs):

• Extracts heat from the outside air.

• Lower installation costs and versatile for various properties.

  
  

Ground Source Heat Pumps (GSHPs):

• Utilises heat from the ground via buried pipes.

• Offers high efficiency, suitable for rural properties with space.

  
  

Water Source Heat Pumps (WSHPs):

• Draws heat from nearby water bodies like lakes or rivers.

• Highly efficient, dependent on proximity to water.

  
  

Hybrid Heat Pumps:

• Combines an air source heat pump with a traditional boiler.

• Automatically switches between systems to maximise efficiency.

Ground source heat pumps (GSHPs) function by extracting heat from the ground and using it to heat your home. The system consists of a network of pipes, known as a ground loop, buried in your garden. A mixture of water and antifreeze circulates through these pipes, absorbing heat from the ground. This heat is then compressed to a higher temperature using a heat pump.

Inside the heat pump, the warmed fluid passes through a heat exchanger, transferring its heat to your home's heating and hot water systems. Because the ground below us maintains a relatively constant temperature under the surface, GSHPs can efficiently operate even in the coldest winter months. 

The process is reversible in summer, allowing the system to cool your home by extracting heat from inside and transferring it into the ground. This dual functionality makes ground source heat pumps an excellent year-round climate control solution.

Ground source heat pumps (GSHPs) come in various types, each designed to suit different property sizes, soil conditions, and installation spaces. Understanding the differences between these systems is crucial for selecting the right one for your needs.

Closed loop systems

Environmental benefits: Minimally invasive to the environment as they recirculate a water-based solution within a sealed system, reducing the risk of contaminating groundwater.

Price: Installation costs vary based on the configuration (horizontal or vertical); however, they are generally more cost-effective over the long term due to their efficient operation. Closed loop ground source heat pumps generally cost between £10,000 to £20,000.

Maintenance: Requires minimal maintenance since the loop is sealed, reducing the risk of leaks or contaminant entry.

Durability: Highly durable with underground components typically lasting 50 years or more due to the protected environment.

Versatility: Can be installed horizontally or vertically, making them adaptable to different property sizes and geological conditions.

Installation: The process involves digging trenches for horizontal loops or drilling deep boreholes for vertical loops. 

Horizontal loops

Environmental benefits: Uses less energy compared to traditional heating systems, reducing your carbon footprint.

Price: Generally less expensive than vertical loops due to simpler, less invasive trenching rather than drilling. Horizontal loops typically cost between £10,000 to £15,000.

Maintenance: Like other closed loop systems, maintenance is minimal but regular checks are recommended to ensure system integrity.

Durability: Durable, with the main factor being the quality of installation and the non-corrosive nature of the pipes used.

Versatility: Best suited for large residential properties with sufficient land for trenching.

Installation: Horizontal loop systems are installed by digging trenches about 4 to 6 feet deep across a wide area of land. The pipes are laid out in these trenches and then covered with soil.

Vertical loops

Environmental benefits: Efficient in heat exchange due to deeper ground installation, accessing more stable underground temperatures.

Price: More expensive due to the need for drilling deep holes, which requires specialised machinery and can be more labour-intensive. Vertical loops can range from £15,000 to £25,000.

Maintenance: Low maintenance needs, similar to horizontal loops, but inspections are crucial to ensure no issues with the deeper installations.

Durability: Extremely durable as they are less affected by external temperature changes and surface conditions.

Versatility: Ideal for smaller plots of land or when surface space is limited, offering a solution where horizontal loops are not feasible.

Installation: Vertical loop systems require drilling deep boreholes, typically ranging from 100 to 400 feet deep, depending on the ground conditions and heating requirements. This process involves specialised drilling equipment and skilled technicians.

Open loop systems

Environmental benefits: Utilises natural groundwater which is an efficient heat transfer medium, potentially reducing the system's energy consumption.

Price: Can be cost-effective where water resources are abundant; however, potential costs for water rights and ongoing water quality management may apply. Open loop systems usually fall between £10,000 to £20,000.

Maintenance: Requires more maintenance than closed loops due to the need to ensure water quality and manage discharge responsibly. These checks typically involve periodic checks of the heat pump components, fluid levels, and the integrity of the piping to ensure efficient operation and prevent leaks.

Durability: Subject to the quality of the groundwater; impurities in water can lead to scaling or corrosion, impacting system longevity.

Versatility: Dependent on local water availability and regulations, making them less versatile geographically but very effective where conditions permit.

Installation: Open loop systems involve tapping directly into an existing water source, such as a well, lake, or aquifer. The installation process includes setting up a pump to draw water into the heat pump where heat is extracted (or deposited, depending on the season) and then discharging the water back to the source or into a different approved discharge area.

Other requirements and considerations

When considering a GSHP, there are several factors to consider:

Space: Ensure you have adequate land for the loop system, whether horizontal or vertical.

Soil and rock conditions: These affect the system’s efficiency and the installation cost. Sandy soil is ideal for heat transfer, while rocky terrain may require more complex drilling techniques.

Water availability: For open-loop systems, a reliable water source is crucial.

Local regulations: Some areas have specific regulations regarding ground and water source use, which could impact system type and installation.

Budget: Initial installation costs can be high, but the long-term energy savings and low maintenance costs can offset this.

Choosing the right type of GSHP system involves balancing these factors with your specific heating and cooling needs to ensure optimal efficiency and environmental benefit.

All heat pumps function using a loop system, but the type of heat pump model can vary too. As we discussed earlier in this guide, there are four different types of heat pumps.

Ground Source Heat Pumps (GSHPs):

GSHPs utilise a network of underground pipes to extract heat from the earth.

This method uses the stable subterranean temperatures to provide efficient heating and cooling throughout the year.

Air Source Heat Pumps (ASHPs):

These systems extract heat from the outdoor air.

Easier to install and generally less costly than GSHPs, their efficiency, however, can diminish in extremely cold weather.

Water Source Heat Pumps (WSHPs):

WSHPs draw heat from nearby water sources such as lakes, rivers, or aquifers.

Like GSHPs, they take advantage of stable temperatures, in this case of the water, which can offer highly efficient heating and cooling.

Hybrid Heat Pumps:

Hybrid systems combine the features of air source heat pumps with another heating technology, such as gas boilers. This allows them to optimise energy use by switching between technologies based on temperature, thereby enhancing efficiency and reliability.

Each of these heat pump types offers unique advantages and is suited for specific applications.

Ground source heat pumps (GSHPs) are a sophisticated yet straightforward system designed to heat and cool your home by exploiting the consistent temperature of the earth beneath the surface. To understand the efficiency of GSHPs, it's crucial to familiarise yourself with their main components.

Evaporator coil

The evaporator coil plays a vital role in absorbing heat energy from the ground loop fluid. As the cold fluid from the underground pipes passes through the evaporator coil, it warms up due to the heat transfer process.

Compressor

The compressor is the heart of the heat pump system. It compresses the refrigerant gas, increasing its pressure and temperature. This is essential as it enables the heat to be effectively transferred to the heat exchanger and into your home’s heating system.

Condenser coil

Once the refrigerant has been compressed, it moves to the condenser coil. Here, the high-temperature gas transfers its heat to the cooler air or water of your heating system. This process cools the gas back into a liquid form, which flows toward the expansion valve.

Expansion valve

The expansion valve is a crucial component that controls the flow of refrigerant into the evaporator coil. The right amount of refrigerant ensures efficient operation of the system, which maintains ideal pressure and temperature levels throughout the cycles.

Each component of a ground source heat pump is integral to its overall function. By working in harmony, they provide a reliable, efficient way to manage your home’s temperature and reduce your environmental impact.

In a ground source heat pump (GSHP), the heating cycle starts with the underground loop system absorbing thermal energy from the earth. This heat is transferred to a fluid that carries it to the heat pump's evaporator coil, where it evaporates the refrigerant. 

The compressor then increases the pressure and temperature of this gas, which passes through the condenser coil, releasing heat to your home's heating system. The refrigerant condenses back to liquid, cycles through the expansion valve to reduce its temperature and pressure, and starts the process over.

The cooling cycle details

For cooling, the GSHP cycle reverses. Indoor heat is absorbed by the evaporator coil and carried away by the refrigerant. After compression, this heat is expelled into the ground via the condenser coil. The refrigerant will then be cooled and liquified by releasing its heat, returning to the evaporator via the expansion valve to continue absorbing indoor heat, effectively cooling your home.

The importance of the reversing valve functionality

The reversing valve is crucial for switching the ground source heat pump between heating and cooling. It changes the refrigerant’s flow direction depending on whether heat needs to be absorbed from or expelled into the ground, allowing the system to adapt to both summer and winter needs. This versatility is key to the GSHP's efficiency in providing year-round climate control.

Selecting the appropriate ground source heat pump (GSHP) is crucial to ensure efficiency, comfort, and cost-effectiveness. Here’s how to determine the best GSHP for your home.

Assessment of home requirements

Before choosing a GSHP, it’s important to evaluate your home’s specific heating and cooling needs. Consider factors such as the size of your property, the existing heating system, and your climate.

We recommend consulting with a professional who can conduct a detailed energy audit will provide insights into your home's energy profile and help tailor a GSHP system to your specific needs. This step is vital in avoiding under or oversizing, which can lead to inefficiencies and increased costs.

Size and insulation

The size of the ground source heat pump should be directly proportional to your home's energy demands, which are influenced by the property's size and its insulation quality. 

In our experience, a well-insulated home requires less energy to heat and cool, which may allow for a smaller, less expensive GSHP system. On the other hand, a larger or poorly insulated house might need a more robust system to maintain comfort, in which case we’d suggest opting for a slightly more expensive heat pump model.

Ground source heat pumps offer significant environmental benefits, primarily through their efficient use of energy and reduction of carbon emissions. Since they use the stable underground temperature to heat and cool your home, they require less electricity compared to conventional heating systems. In our experience, this efficiency translates into lower energy bills and a smaller carbon footprint.

Moreover, GSHPs can be powered by renewable energy sources, such as your own solar panels, further decreasing their environmental impact. They do not emit pollutants locally, which is beneficial for air quality around your home. In our experience, we’ve found that the system’s long lifespan, combined with the minimal maintenance it needs - contributes further to its eco-friendly credentials.

By choosing a ground source heat pump, you’re not only ensuring efficient heating and cooling but also contributing to a more sustainable future. Isn’t it reassuring to know that your comfort at home can also mean taking care of the planet?

SpotDif is your go-to resource for comparing local ground source heat pump providers to discover the best options. We tap into our network of trusted GSHP suppliers and evaluate their systems, efficiency, and pricing for you.

Begin your search for efficient and cost-effective ground source heat pump solutions, or reach out to us today to get started.