Which is best for you? Ground source heat pumps or air source heat pumps. 

The choice between air source heat pumps and ground source heat pumps has always come down to a mix of different factors. Here we will do our best to explain what may affect your choices. 

Free space

Often the choice comes down to how much available space you have outside your house. An air source heat pump only needs a couple of square meters of the outdoor space, compared to a ground source heat pump, which will often require an acre or more of open space. A ground source heat pump will either require space for boreholes or a horizontal collector array if at all possible. If this isn’t possible, then an air source heat pump will be the only realistic option.


The installation of a ground source heat pump will always be higher. Often the cost will be between 30%-60% more than installing an air source heat pump. Purchasing an air source heat pump is in the short term far less than a ground source heat pump, however, the running costs of an air source heat pump over time are going to be higher than that of a ground source heat pump. What this means is that the payback period for a ground source heat pump will be sooner than that of an air source heat pump. Ultimately it comes down to short-term pain vs long-term gain. 

Electrical supply 

Air source heat pumps in the UK must deal with the serious humid weather conditions that are typical here. As a result, installers need to use a bigger than usual capacity heat pump, compared to most neighboring countries and also compared to installing ground source. A common issue is that most houses lack an adequate electrical capacity on-site to run an air source heat pumps enough. If the aim is to totally remove the current heating system, this will usually have to be changed or upgraded. This can make ground source is the only reasonable option for those who are unable to change their electrical capacity. That being said, It is possible to install a heat pump that provides some of the heating, and leaving the remaining heating needs to a fossil fuel boiler. It all depends on the circumstances and personal choices. Of course, the former option is better for the environment. 

One size does not fit all 

To sum it up, there are a range of factors that should be considered when looking to decide to go with one technology over the other. Our advice is to speak to your trusted local installer. What people initially assume is the best option, is not always the case. People usually find through consultation that there are more appropriate options that can provide greater savings and benefits, to uncover these requires a professional taking a detailed look at your home and grounds. We at Greenerguide don’t promote one specific technology over another. We believe it is better to champion a system that is the best fit for the site.