Ground Source Heat Pumps
How do they work?
A ground source heat pump (GSHP) is a heating system that extracts heat from the ground and uses it to provide heating for a property. It works by utilizing the relatively stable temperature of the ground to transfer heat energy to the home. Here's how a GSHP works for a UK homeowner looking to install a new heating system:
1. Ground Loop Installation: To install a GSHP, a ground loop system is installed in the ground adjacent to the property. This can be done through horizontal trenches or vertical boreholes, depending on the available space and geological conditions. The ground loop consists of a series of pipes that circulate a fluid, typically a mixture of water and anti-freeze.
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2. Heat Absorption: The fluid in the ground loop pipes absorbs heat energy from the ground. The ground itself acts as a heat source, as it maintains a relatively constant temperature throughout the year, usually between 8 to 12 degrees Celsius in the UK. The fluid collects the heat from the ground and becomes warmer as it circulates through the ground loop system.
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3. Heat Exchange: The warm fluid from the ground loop is pumped into the heat pump unit inside the property. The heat pump contains a refrigeration cycle similar to that of an air conditioning unit but in reverse. The warm fluid passes through a heat exchanger, transferring its heat energy to a refrigerant within the heat pump.
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4. Refrigeration Cycle: The refrigerant in the heat pump absorbs the heat from the fluid and evaporates into a gas. The gas is then compressed by a compressor, which raises its temperature further.
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5. Heat Distribution: The hot refrigerant gas passes through a second heat exchanger, known as the condenser. In the condenser, the heat is transferred to a water-based central heating system or directly to the home's underfloor heating or radiators.
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6. Expansion Valve: After releasing its heat, the refrigerant returns to a liquid state and passes through an expansion valve, which reduces its pressure. This prepares the refrigerant to repeat the cycle of heat absorption from the ground.
7. Indoor Distribution: The heated water or air is distributed throughout the home, providing warmth and comfort. It can be circulated through radiators, underfloor heating systems, or air handling units, depending on the specific heating system setup.
GSHPs offer several benefits for UK homeowners, including energy efficiency, cost savings, reduced carbon emissions, and a reliable heating solution. However, installing a GSHP requires careful consideration of factors such as available land or space, soil conditions, and system design.
Benefits of installing a ground source heat pump?
Energy efficiency
GSHPs are highly energy-efficient heating systems. They harness the consistent temperature of the ground to provide heating, requiring less electricity or fuel compared to traditional heating systems. This results in lower energy consumption and reduced heating costs, helping homeowners save money in the long run.
Reduce energy bills
By utilising the heat energy stored in the ground, GSHPs can significantly reduce heating bills. Although the upfront installation cost may be higher than conventional heating systems, the lower running costs and potential government incentives, such as the Renewable Heat Incentive (RHI), can offset the initial investment and lead to substantial savings over the system's lifespan.
Environmental friendliness
GSHPs are environmentally friendly heating solutions. They use renewable energy from the ground, reducing reliance on fossil fuels and lowering carbon emissions. By choosing a GSHP, homeowners contribute to the UK's sustainability goals and help combat climate change.
Space saving
GSHPs require less indoor space compared to traditional heating systems like boilers or furnaces. The main components, such as the heat pump unit, can be compactly installed, freeing up valuable space in the home.
