Ground Source Heating

A Ground Source Heat Pump (GSHP) is a unit which absorbs heat either directly or indirectly from the ground. This is done by extracting and re-injecting water from an aquifer (direct) or by using a ground heat exchanger (indirect). A closed loop of pipework buried within the ground (vertically or horizontally) is called “the exchanger”.  It then upgrades this low temperature heat into useful higher temperature heat energy for space heating and domestic hot water. Switching from an oil boiler to a ground source will reduce your heating bills by approx 30-40%. The RHI grant payments can be as high as £30k, so a lot more than other forms of heating (paid over 7 years following the installation)  For more information about sustainable heating solutions using ground source heat pumps with underfloor heating visit the National Energy Savings Trust website.

 

Some information about GSHPs:

What is a ground to water heat pump?

A device which extracts energy from the ground and uses it to heat water.

 

How does it work?

A ground to water heat pump absorbs low temperature energy from the ground and raises it to a higher, more useful temperature using a refrigerant cycle and uses water to deliver the heat. A heat exchanger transfers the energy from the ground to a refrigerant with a low boiling point which evaporates and circulates in a closed system. The pressure of the refrigerant gas is raised by a compressor, which also raises the temperature to a useable level. The refrigerant then condenses in a second heat exchanger and releases heat to a water delivery system. The pressure of the refrigerant is then reduced by an expansion valve, its temperature falls, and it is ready to start the cycle again and absorb energy from the ground (Reference GSHPA for more details)

How Efficient Are Ground Source Heat Pumps?

For every kW of electricity consumed by the heat pump, around 4 kW’s of heat is generated in return, meaning you have a 400% cost-effectiveness ratio.

 

GSHP systems save energy by using the constant temperature of the ground to increase the seasonal efficiency of home heating. The source of heat used for ground source heat pumps is the sun, as it heats up the ground water resulting in the stable temperature of the Earth’s floor.  

Are Heat Pumps Efficient in Cold Weather?

Heat pump's external pipelines are inserted in the soil, which keeps its temperature below 1 meter relatively stable all year round. For this reason, cold weather is not likely to affect your heat pump's efficiency significantly, and even less so if you have a vertical GSHP.

Drawing as much as 75% of the energy needed by the heating system from freely available, inexhaustible solar energy stored in the earth, our Ground Source Heat Pumps are available in an extensive range of models types and capacities suitable for either domestic or commercial applications. Due to highly stable temperatures below the earth’s surface, ground source heat pumps provide high levels of efficiency for space and water heating all year round

 

The operating range of the heat pump

— the temperature of the water/ antifreeze solution entering the heat pump from a closed loop ground collector will depend on the ground temperature and ranges from about 12oC to just above 0oC. The temperature drop across the heat exchanger is usually between 3oC and 5oC. The fluid in a closed loop ground collector should be protected from freezing down to at least –15oC. The maximum water temperature for heating is typically 55oC but can be up to 65oC.

The type of heating distribution system, including any buffer/storage tank arrangement

Space heating

This is the main application. The lower the distribution temperature in the heating system the higher the efficiency of the heat pump will be. Heat pumps are therefore best suited for use with low temperature heating systems such as:

  • Underfloor heating (delivery temperature 30-45oC).

  • Fan coils (delivery temperature 35-55oC).

  •  Low temperature radiators (delivery temperature 45-55oC).

 

Domestic hot water

Heat pumps able to provide supply water in the range 60-65oC can provide full water heating.

 

Ground source heat pumps
  • Efficient option for properties on larger plots

  • MCS approved for the Renewable Heat Incentive

  • Intuitive display for ease of use

  • Ground loop and borehole options available

 

Made Affordable 

Ground source heat pumps are an effective as well as environmentally friendly investment that can help you save up to 50% on heating bills when compared to conventional heating systems. Initial investments are high, but the ground source heat pump prices vary depending on the project. Some of the many advantages of ground source heat pumps (GSHP) include:

 

  • Save £790 to £1425/year on your heating bill price when replacing an electric system

  • Indoor components last approximately 25 years

  • Ground loops last 50-100 years

  • Equal distribution of heat

Since the Earth absorbs energy released from the sun, underground temperatures remain constant year round. In the UK, the temperature of the Earth a few metres below our feet is constant around 11 degrees Celsius. The purpose of ground source heat pumps is to absorb heat from one place and transport and release it to another location, in this case, your home.

 

Ground to water heat pumps are suitable for both new build and retrofit

The ideal site:

●  Is new build (easy to use low temperature heating system).

●  Has no access to gas (relatively high fuel prices).

 

Advantages

●  High efficiency.

●  Low energy consumption.

●  Low running costs.

●  Low carbon emissions (lower than gas condensing boiler).

●  Relatively low noise (lower than an air source heat pump because there is no external fan noise).

●  Low maintenance and long life (the ground collector should have a life of at least 50 years).

 

Aspects to consider

●  Area required (for horizontal closed- loop ground collector).

●  Access for drilling rig (for vertical closed-loop ground collector).

 

 

Financial Incentives

Possible grants are available for domestic and commercial installations (Low Carbon Building Programme, or from Electricity suppliers).

 
Can I use under floor heating with heat pumps?

Yes! Underfloor heating is the most popular heat emitter to pair with a heat pump system. This is because underfloor heating works at much lower flow temperatures than a traditional radiator system, making it ideal for heat pumps which are at their most efficient when operating at low temperatures.

 

We will design and supply a fully integrated heating solution that combines the full range of under floor heating benefits with your energy-efficient heat pump.

 

  • Low flow temperature solution

  • Up to 40% more efficient than a boiler and radiators system

  • Reduces energy bills and carbon footprint

  • Qualifies for the RHI (Renewable Heat Incentive)

  • Fully designed and integrated heat pump and underfloor heating solution from a single supplier 

  • Warm water underfloor heating running costs

  • Warm water under floor heating is a highly efficient heating system – around 25% more efficient than radiators when paired with a modern condensing boiler and up to 40% more efficient when running from a heat pump

  • Because of this, running costs are often lower than a traditional radiator system and around a third of an equivalent electric underfloor heating system.

  • underfloor heating cost in a renovation

  • More materials are supplied with retrofit warm water underfloor heating systems (e.g. pre-routed panels or specialist self-levelling compound), so for this reason they tend to cost more than a new build system.

  • In a renovation project, like an average Victorian terrace with a downstairs floor area of 60m², a bespoke system would cost in the region of £4000, or £65m². This would include everything required to install the underfloor heating so that it is ready for the chosen floor finishes, as well as a bespoke design system and an unrivalled level of customer support for the entire lifetime of the system.Installing underfloor heating in one room?

  • Electric underfloor heating kits, cost less than warm water, making them a good option for smaller, single rooms. Be aware that electric underfloor heating running costs are far higher than warm water, meaning it is best avoided for heating large spaces or a whole house.

  • underfloor heating cost in a new build

  • Screed under floor heating is a cost-effective heating choice for a new build property that fits neatly into the build schedule. Installation is quick, which helps keep costs to a minimum.

  • In a typical self-build project (e.g. a detached 3 bedroomed home) with a 100m² floor area, you could expect a bespoke screed underfloor heating system to cost approximately £2800-£3000, or £30m², excluding the screed. This would include a unique system design tailored to the property, the highest quality components and support for the lifetime of the system.

  • Qualified and experienced underfloor heating experts to ensure the system performs exactly as required handle every project.

Underfloor heating running costs: Warm water Vs Electric

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