Ground source heat pumps utilise renewable energy and convert it into a usable form for domestic heating purposes using distributors, including radiators, floor heaters, and water heaters. These heat pumps easily replace conventional electric heating for a more sustainable source.
Like any long-term and reliable alternative to an energy supply, ground source heat pumps or GSHPs also require a substantial upfront cost that might put off a lot of people considering this option. Do not be overwhelmed by the hefty numbers thrown around casually for GSHP installation, because they do not explain the long-term investment behind it.
That is precisely what we will unpack in this blog and explain the installation process of GSHPs from start to finish. We will also explore the available types of ground source heat pumps, pre-installation criteria you need to consider, cost implications, and how to know if installing a GSHP is the right choice for you.
What is a ground source heat pump, and how does it work?
GSHP or geo thermal heat pump consists of looped coils laid underground to convert the geothermal renewable energy to an everyday alternative heating for your house or workplace. The capacity of a ground source heat pump is measured in kilowatts. A typical GSHP operates at an 8kW -12 kW heating system capacity, sufficient for an average-sized property in the UK.
The complete system can be divided into three major components: the underground coils, the heat pump and the indoor heat dispenser (floor heating or radiators).
Here is how the heating mechanism works in simple words for understanding:
- Underground coils: There is a heat-absorbing liquid inside the underground coils, which takes in the natural heat of the ground. This heated fluid then travels to the heat pump unit and transfers its warmth to another liquid (specialised coolant) inside the heat pump.
- Heat pump unit to distribution: A series of evaporation and compression processes take place to send the heat inside the property and distribute it through radiators, water taps or floor heaters. The intermediate processes efficiently control and convert the high-temperature heat from the ground to a useful form of energy that can be consumed.
Types of ground source heat pumps
The type of ground source heat pump you choose mainly depends on the ground area available around the property.
- If plenty of space is available around your property, then that land surrounding your home or office can be dug to lay the coils in a horizontal ground loop installation. This requires a wide surface area, which results in needing more peripheral land.
- If that is not an option, you can consider vertical loop installation, in which the coils or pipes are laid vertically instead of a horizontal framework. This requires the ground to be dug up more in terms of depth, but you can save space on surface area.
Pre-installation planning and criteria
Installation is the part that potential customers are most concerned about. But if you carry out proper analysis before starting it, the procedure becomes easier to handle. The process must be done by a professional, but it’s useful to have an idea of what actually happens during it. A professional from your chosen installer would have to visit your property and take note of the following aspects.
Insulation in your property
Before signing up with any installer, you must make sure your property is properly insulated. That is because ground source heat pumps deliver heat at subtle levels, which need to be stored to be retained. Only then can the stored heat provide warmth for a longer time and efficiently use the energy without wasting it.
If your house lacks insulation, the heat will escape as soon as it builds up and won’t provide the necessary warmth. To avoid that, it is worth investing in insulation first before moving forward with the installation. It is an additional expense, but it will ensure your hefty expense of GSHP is worthwhile without wasted resources.
Land required
The available ground around a property is an essential part of the pre-installation check-up. Ideally, there shouldn’t be any fixtures on it, and it should be smooth and ready for digging. Depending on the chosen type of ground source heat pump, the area of land required is different.
- For a ground loop heat pump, on average, a domestic installation would need 1500-2000 square meters of land, which is dug 1-2 m deep in the ground.
- For vertical loop installation, less surface area of the land is required, but the digging must be almost 50-150m deep, where the pipes will be buried.
Length of coils
Property assessment allows the installers to predict the estimated energy consumption of the property. It is important to analyse beforehand, because it determines the length of the coil for underground installation. On average, one loop of coil is usually 400-450 m according to industry standards. Depending on the size of the heat pump, you may require 2 or more of these 400-450 m coil loops.
Ground source heat pump installation steps
Once all the pre-installation criteria are completed, a major portion of the process is covered. The underground infrastructure can be either a vertical or horizontal ground loop, and heat source radiators or floor heating. The installation process differs a bit in each case, so let us check it step by step.
Step 1: Consider the prerequisites
The first step is to complete the pre-installation criteria that we have already discussed in detail. This step is important because it helps make appropriate decisions depending on your specific property dynamics and heating needs.
Step 2: Establishing the groundwork
The next step is laying down the groundwork. For horizontal ground loop installation, the minimum land requirement is 2,000 square metres of land. Shallow trenches are dug, and the coils are “looped” before connecting to the heat pump. Similarly, in the vertical loop installation, a narrow area of ground is dug for a depth of at least 50m. The coils are then buried in the boreholes and connected to the heat pump. The term “boreholes” simply means a vertical cavity in the ground.
Step 3: Setting up the indoor heating distribution
The third step is installing the heat distribution system inside your property, which dispenses heat. If this step is discussed during the preparation phase, as we suggest, you can save time during the process.
There are two main options of underfloor heating or traditional heaters. You can install either one of them or both in combination as well. Both of these options have their own implications.
- Ground source heat pumps deliver slow and gradual heat, so floor heating is the most suitable option to go with them. However, installing traditional radiators is also possible, but they have space and cost considerations. The radiators would be bulky with a large surface area to provide considerable heating (due to the gradual and low temperature heat delivery of ground source heat pumps).
- Ground source heating pumps can also heat water stored in a cylinder. However, it is important to note that the heat delivered is slow and progressive, so water for taps and home usage takes time to be moderately heated. If it matches your needs, then you can save on electric water heaters and switch to heating water by the GSPs altogether. But if the water temperature is not up to your standards, then there are options for installing a backup electric heater for household water usage, taps and hot showers.
Step 4: Installing the heat pump unit
The next step is to install the heat pump unit in your property, which connects all the components of the system (coils and radiators). The capacity of the heat pump is measured in KW, and it depends on the predicted energy needs of your property. This ultimately decides the maximum heating limit that the ground source heat pump is capable of.
Step 5: Running tests for proper functioning
Once the installation is completed, the system should be tested for proper functioning, and the thermostats will be installed, which help monitor and adjust the heating system.
Cost of installing ground source heat pumps
The average cost of installing a ground source heat pump in the UK is £18,000 and £36,000.
The total average cost depends on multiple factors, including:
- The current insulation of your property
- Size of your property
- Availability and condition of the surrounding land
- Exact location in the UK
- Required heating capacity
- Whether you choose a vertical or horizontal ground source heat pump.
The major cost of infrastructure, digging, and laying down the framework, condenses to the type of ground source heat pump you choose. Which ultimately depends on the area around the property, and there’s a little flexibility in that aspect.
Here are the major costs relevant to the ground source heat pump installation, you will encounter:
| System component | Costs in the UK | Costs in the UK |
|---|---|---|
|
Heat pump unit capacity |
8kW (£12,000- £13,000) |
12kW (£14,000- £15,000) |
|
Groundwork and digging |
Horizontal (£3,000- £5,000) |
Vertical (£7,000- £9,000) |
|
Heat distributors |
Floor heating (£1,000- £3,000) |
Radiators (£4,000- £5,000) |
How long does the installation process take?
The length of the installation process depends on the extent of your planning, property condition and the heat pump capacity. A property with 4-5 bedrooms requires more underground coil loops to be installed, which means more digging and larger infrastructure as compared to a property with 2-3 bedrooms.
So the installation times vary widely, which can only be predicted after the pre-assessment of your property. However, as a rule of thumb, it can take anywhere from 7 days – 3 weeks just to complete the installation. The time for pre-installation analysis is not included in this and must be accounted for separately.
Do I need to get a grant to install a ground source heat pump?
In the UK, generally, you should not need a permit for installing a ground source heat pump if you are a homeowner. However, if you are renting, live in an apartment or a shared building, then it’s worth consulting your local council to check for any regulations before digging up the ground for installation.
Is a ground source heat pump right for me?
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All you have to do is tell us about your project, and we will do all the hard work and match you with a reputable ground source heat pump provider.
FAQs
How much time does it actually take to install a ground source heat pump?
Including the house visits, insulation checks and pre-installation evaluation, the complete process takes 4-6 weeks. However, the groundwork takes 7 days to 3 weeks, solely including the digging and establishing the infrastructure.
Installing a ground source heat pump is a more eco-friendly and sustainable option than utilising electrical energy for complete house heating. That is because it uses the renewable heat energy directly from the ground, with an endless supply, so there is no stress of running out. It also reduces carbon footprint and provides a long-term solution to all heating needs of your property.
