Ground Source Heat Pumps

Is a Ground Source Heat Pump suitable for your property?

A Ground Source Heat Pump can heat your home using free heat energy absorbed by the Earth from the Sun. If you have the land, you can heat your home with this free energy.

How do Heat pumps work?

Heat Pumps work by extracting latent heat energy from the environment (either from the atmosphere, from under the ground or from a lake or river) to heat a property and produce hot water. The environment around us absorbs and stores heat energy from the sun. This heat energy is stored at low temperature and in order to make it useful for heating purposes the temperature of this stored heat energy needs to be increased.

In a Ground Source, or Ground to Water, Heat Pump for example, an array of underground pipes, containing a water and glycol based antifreeze mixture, known as brine, absorbs heat from the ground, (at a depth of approximately 1m – 1.2m this heat energy is at a fairly constant temperature of 10 – 12oC). The brine then passes through a heat exchanger within the heat pump and transfers its captured heat energy to a refrigerant gas, which has a low enough boiling point so that the heat energy stored in the brine causes it to evapourate. This evapourated gas then passes into a compressor; compressing the refrigerant gas, causing the temperature to increase.

The compressed gas then passes through another heat exchanger, known as a condenser, where the stored, higher temperature heat energy is transferred into the property to provide heating and domestic hot water. As the refrigerant gas gives up its stored heat energy, it condenses back into a liquid and begins its circuit back around the heat pump.

How a heat pump work

The compressor and circulation pumps within the heat pump require an electrical supply, but because most of the heat generated by the heat pump is free heat energy drawn from the environment, heat pumps are typically 350% – 450% efficient, so for every 1 Kilowatt of electricity used, the heat pump will generate 3.5 – 4.5 Kilowatts of heat.

In order to achieve these levels of efficiency and maintain low running costs, heat pumps are best suited to well insulated, new build properties or properties that have been renovated to new build standards and they need to produce flow temperatures as low as possible; typically, between 35oC and 45oC. Because of this, heat pump installations must be designed in unison with the heat emitters, whether they are radiators or underfloor heating.

The advantages of all heat pumps is that they have minimal maintenance requirements, long service lives and when installed correctly will provide very cost affective heating for years to come.

How a ground source heat pump supplies your home

The fluid which is contained within the outdoor underground pipes absorbs energy. This is then transferred via a pump to the heat pump and converted via a process of compression into heated water which is made ready for circulation to warm your radiators or underfloor heating and for use with hot water at your taps. The cooled fluid (after passing its heat into the home’s water and central heating system) continues back underground to absorb further energy in a continuous loop.

How a heat pump work

The compressor and circulation pumps within the heat pump require an electrical supply, but because most of the heat generated by the heat pump is free heat energy drawn from the environment, heat pumps are typically 350% – 450% efficient, so for every 1 Kilowatt of electricity used, the heat pump will generate 3.5 – 4.5 Kilowatts of heat.

In order to achieve these levels of efficiency and maintain low running costs, heat pumps are best suited to well insulated, new build properties or properties that have been renovated to new build standards and they need to produce flow temperatures as low as possible; typically, between 35oC and 45oC. Because of this, heat pump installations must be designed in unison with the heat emitters, whether they are radiators or underfloor heating.

The advantages of all heat pumps is that they have minimal maintenance requirements, long service lives and when installed correctly will provide very cost affective heating for years to come.

Key steps when having a ground source heat pump installed

Optimum ground source heat pump efficiencies hinge on a system that is correctly designed and installed for an individual property, which is why it’s important to use a qualified installer. To make sure of a system that perfectly matches your home and your heating and hot water needs, a professional installer will work to three key stages:

Pre design assessment with Cedar Renewables

1. Pre-design assessment

This stage is to determine which heating system will best suit your property and the feasibility of your preferred system. With years of experience in the renewable heating industry Cedar Renewable will be able to advise you on the most beneficial system for you. We can produce a budgetary estimate, detailing the work required and including different options, where applicable.

Renewable heating design by Cedar Renewables

2. Detailed design

Should a Ground Source Heat Pump prove to be the most advantageous system for you, we will begin the detailed design process. This will include carrying out test digs to determine how much heat can be extracted from the ground and therefore the size and type of the collector array required, (whether horizontal collectors or boreholes), a full heat loss survey to determine the heating and domestic hot water requirements of your property and a heat emitter design to ensure the heat is transferred efficiently into your property. All of this information will be included in our full quotation, along with a performance report detailing the estimated energy savings and Renewable Heat Incentive payments that you could receive.

Ground Source heat pump installation from Cedar Renewables

3. Specification

Our team of qualified engineers, led by one or both of our directors will be onsite to complete the installation. We will organise the required subcontractors to complete the groundworks, if required. All other work will be completed in house, including the laying of horizontal collector arrays, manifolds and header pipes, installation and connection of the heat pump, buffer tank and heat pump cylinder. We can also complete the installation of the underfloor heating and or radiators, depending on which is selected, connection of the heating controls and final commissioning of the system. Upon completion you will be provided with a full handover pack and we can even assist in the application for the RHI.

What is the Renewable Heating Incentive?

The Domestic Renewable Heat Incentive is open to applicants who wish to upgrade to a renewable heating technology in a domestic property that they own.