Ground Source Heat Pumps

What is a ground source heat pump?

Energy from the sun is absorbed into the ground, regardless of whether it’s cloudy or not. Therefore the earth in your garden provides an excellent source of heat energy which can be extracted from the ground and transferred to a building using a ground source heat pump (GSHP). A GSHP works like a reverse, CFC free refrigerator and can generate up to five times the energy required to operate the pump (powered by electricity). The savings to your energy bill will depend on your existing heating method. The benefits when compared to oil or electrical based central heating far outweigh the electricity cost of running the pump.

How does a ground source heat pump work?

Are all properties suited to heat pumps?

Both new and existing buildings, even older style properties, listed buildings, country houses and commercial properties. Claywood energy are able to advise on bespoke solutions which take into account every element of your property and your individual requirements.

Do I need underfloor heating for a heat pump?

No. Both Ground and Air Source Heat Pumps can work with existing heating and hot water systems but some modifications may be required, such as insulation and over sizing radiators. 

Is it possible to use a heat pump for swimming pool heating?

Yes. Both ASHPs and GSHPs are suitable for swimming pool heating. The savings can be considerable.

Can heat pumps be used for cooling?

Heat pumps have the ability to provide both heating in the Winter and cooling in the Summer.

What are the grants/ financial incentives available for heat pumps?

Currently the available grant is called the Renewable Heat Incentive, which helps with the installation costs. 

Are ground source heat pumps really green?

The key to a heat pump is it’s Coefficient of Performance (COP), the ratio of heating and hot water produced (in kWs) versus the electricity needed to run the system. If installed correctly heat pumps offer an extremely efficient heating system and the sun’s energy from the ground is a completely renewable source.

Are GSHP safe and what about maintenance?

Maintenance requirements are minimal. After installation ground loops are pressure tested and then buried, at which point the system requires no regular servicing or annual safety checks. There are no hazardous gas emissions, no flammable oil, LPG or gas pipes, no flue or chimney and no fuel tanks.

What sort of efficiency can I expect from a GSHP?

Modern systems are very efficient. For each kilowatt of electricity used to run the heat pump, three to four kilowatts of heat are delivered to the building, i.e. a COP of 3-4. We urge extreme caution selecting an installer as the design and installation will impact the COP. 

Is my house suited to a ground source heat pump?

With our honest and straightforward approach if we do not think a GSHP is suitable for your property we will suggest alternative renewable options, or a heating system based on a modern energy efficient boiler instead. However, GSHPs can work in a wide range of buildings, if the system is designed and sized correctly. Some upgrades may be required, such as improving your homes insulation to maximise its efficiency. It works with both underfloor heating and radiators, but the latter may need to be resized to meet the buildings heat load. Before we would recommend installing a heat pump we will make suggestions to ensure that your property is correctly insulated and draft proofed to get the full benefit of the system. As a proportion of the total installation cost, this is likely to be a small percentage, but can create the greatest benefits to your energy savings.

How much land do I need?

This is one of the most frequently asked questions about ground source heat pumps. It really does depend on the age, size and current insulation levels of the property.

A small property can require anything from 300m of ground collectors up to 2km for a large country house. The actual size of the internal unit is roughly equivalent to an upright fridge freezer and this can be positioned in a garage, car port, outbuilding or basement.

There are two main types of heat collection method available, the first being horizontal where collection pipe is buried in a series of loops (most space consuming), the second being vertical boreholes, which requires significantly less space where collection pipe is sunk vertically into the ground up to 200 metres deep.

What will it cost?

The cost of installing a system clearly depends on the size of the property. The Energy Savings Trust provides an estimated range EST – GSHP, but in reality each system is bespoke to the individual property and we will fully evaluate your total heating and hot water needs, coupled with any changes that might be needed such as improved insulation.