What’s the Difference Between Ground & Air Source Heat Pumps?

April 24th, 2017 by Airedale Cooling

Heat pumps provide an inventive solution for heating and cooling your business. As a renewable form of heating, there has been increased interest in the methods, especially amongst those who are environmentally conscious. Due to the fact heat pump methods are a non-traditional system, many people don’t know much about them – something which we aim to remedy in this article! We shall consider both ground source and air source heat pumps, how they work and how they compare to each other.

How do they work?

Both ground source heat pumps (GSHP) and air source heat pumps (ASHP) work in a similar way. Each of the heat pumps has a fluid-containing part of the system outside which absorbs heat from its surroundings. Ground source systems have underground pipes installed which contain the fluid which absorbs heat from the ground; air source systems have an outdoor unit which contains the fluid and absorbs heat from the air. The warmed fluid then passes through a compressor which applies pressure to enhance the fluid’s heat – this heat is then utilised by the central heating system to warm your property. The heat pumps can also work in reverse to cool your property by absorbing and transferring heat from inside the building, outside.

Costs

Due to the different sources of heat, the configuration and costs of installing the different heat pumps does vary quite a lot. Since GSHPs rely on an underground pipe system, the drilling and digging work undertaken to install these pipes drives up the cost. An ASHP, however, only relies on an outdoor unit being installed. A lot depends on the size and heating requirements of your individual property, but for a ballpark figure, you can expect an air source installation to cost several thousand pounds and a ground source to cost around twice that.

Further consideration is needed for how the system will provide the heat in your property. Heat pump systems are efficient at lower temperatures than standard gas heating which can mean that radiators should be as large as possible to distribute most heat. Both systems work best in an underfloor heating system – this can be an added cost if it is necessary to install this as well. Additionally, both systems will work optimally if your building is already well insulated.

Installation

Unsurprisingly, due to the equipment needed for GSHPs, this method has a more complex and disruptive installation process. You’ll need to make sure you have the space available to horizontally fit the underground pipework needed for your heating requirements. If you don’t, drilling will be required to fit the pipes vertically.

Although an ASHP needs less physical space – units are roughly a metre tall by a metre wide – they aren’t necessarily without challenges. Both methods may require you to seek planning permission and you’ll also have to ensure an air source unit doesn’t emit disruptive levels of noise.

Efficiency

The benefits of a GSHP are in its efficiency. You can expect a GSHP to be in the region of 10-25% more efficient than a ASHP which translates to increased energy saving and cheaper heating in real terms. This efficiency is due to the way the different methods work – there is much less fluctuation in temperature underground than in air temperatures which means generally, a GSHP system does not have to work as hard as an ASHP and, therefore, requires less energy.

In comparison with other heating methods, heat pumps are generally much more efficient than electric and coal based heating systems. However, it is unlikely that a heat pump system will be a more efficient alternative to a gas central heating system.

Maintenance

Both heat pump systems are considered low maintenance and, assuming they have been installed properly, will require very minimal upkeep. Annual check ups by a professional are recommended to ensure that the system is in good working order and, especially relevant when the system is older, any issues are dealt with swiftly.

Financial incentives

Both GSHPs and ASHPs are deemed renewable forms of energy and, providing the system meets some basic requirements, are therefore supported by the Renewable Heat Incentive (RHI) scheme. This scheme provides the participators with payments for 7 years according to the amount of green heat their system produces. The RHI payments are worthwhile as they generally accumulate to fund the costs/majority of costs of installing your heat pump system of choice.

Summary

In conclusion, both systems are a great choice of heating system if you are looking for a low maintenance, green, renewable energy source. A GSHP will have higher upfront costs and installation disruption than an ASHP but will have greater benefits, in terms of efficiency, in the long-run, especially when factoring in the RHI. However, which system you choose will likely be largely based upon personal preference.
If you are looking for an experienced and reliable contractor to fit a ground source or air source heat pump system for your home, look no further than Airedale Cooling. We are experts in air conditioning and heating systems with a wealth of industry experience, who operate across Yorkshire. Our quality workmanship ensures your system will be installed safely and efficiently, and we can also provide any necessary maintenance and repairs down the line. Get in touch with us today for any further information about our products and services, or for any general enquiries.