An introduction to ground source heat pumps

An introduction to ground source heat pumps

 

If you are looking for a renewable and cost-effective way to heat your property, a ground source heat pump could be the solution. This simple piece of technology comes hand-in-hand with a range of benefits and it is perfect for both domestic and commercial projects. However, unless you work in the geothermal industry, it is probably something that you have never come across before.

In the following blog, we provide a quick introduction to ground source heat pumps and answer some of the most frequently asked questions regarding the geothermal borehole drilling process.

What is a ground source heat pump?

A ground source heat pump is a heating and cooling system that is installed underground. Radiation from the sun heats the earth’s crust on a year-round basis and, essentially, the heat pump takes advantage of this fact. It transfers the natural heat into a ground loop (i.e. a network of buried pipes), passes it through an evaporator, compressor and condenser and releases it for use.

There are two main types of geothermal heat pump available and it is important to consider which is most suitable for your property. If there is sufficient space, the ground loop can be laid horizontally, approximately a metre below ground. However, in most cases – where available space is limited – a vertical geothermal borehole (around 15-100m deep) will be needed instead.

How does a geothermal heat pump work?

Geothermal heating may sound complicated, especially if you have no prior knowledge of how it works; however, it is actually a very simple process, that can be broken down into 5 easy steps.

  1. Heat is extracted from the soil by the ground loop and absorbed into a refrigerant fluid
  2. This fluid is moved to an evaporator, where it is changed from a liquid to a gas
  3. The gas is subsequently compressed, allowing its temperature to rise
  4. It is then passed through a condenser, or heat exchanger, into a central heating system
  5. Finally, the cooled refrigerant fluid is released back into the ground and the cycle starts again

 diagram of how a geothermal heat pump works

How is a geothermal borehole installed?

Before a geothermal borehole can be installed, the first step is to organise a geothermal survey. This will indicate the thermal characteristics of your site, including whether the ground is suitable for a deep-seated borehole and whether it can be feasibly accessed by large borehole drilling equipment.

Specialist geothermal drilling rigs will then be used to dig a borehole and vertical pipes are inserted. The space between the pipes and the borehole wall is filled with a specialist type of grout and, once all has been completed, a series of tests will be conducted to check that the system works correctly. 

Ground source heat pump boreholes are typically drilled 5-6m apart and should be at least 6-7m from the nearest building. Their depth is determined by the size, insulation and heating capacity of the property and their cost varies depending upon your exact needs and requirements.

Contact Teckna Group for geothermal borehole drilling

Teckna Group is a multi-disciplined drilling and civil engineering company, with a significant level of knowledge and experience in this area. Working alongside accredited MCS ground source heat pump partners, we offer a full turnkey geothermal borehole drilling service – including geothermal surveys, geothermal well drilling, and geothermal pipework – for both domestic and commercial projects.

If you would like to find out more about geothermal heat pumps and how they could be of benefit to you and your property, why not get in touch? Our team of experts are always happy to help and will answer any questions that you may have. Either call us today on 01257 421700 or send an email to enquiries@tecknagroup.co.uk  and we will respond as soon as possible.