Ground Source Heat Pumps



Ground source heat pumps (GSHPs) use pipes that are buried in the garden to extract heat from the ground.

This heat can then be used to heat radiators, underfloor or warm air heating systems and hot water in your home. There has been a lot of speculation about the government’s proposals to ban gas boilers in new build homes from 2025. This means that designers are looking for other, innovative ways to heat our homes.

A ground source heat pump circulates a mixture of water and antifreeze around a loop of pipe, called a ground loop, which is buried in your garden. Heat from the ground is absorbed into the fluid and then passes through a heat exchanger into the heat pump. As the ground stays at a fairly constant temperature under the surface, the heat pump can be used throughout the year. Longer loops can draw more heat from the ground, but need more space to be buried in. However, if space is limited, a vertical borehole can be drilled instead.

What are the benefits of installing a ground source heat pump?

Installing a GSHP could lower your energy bills – who doesn’t like saving a bit of cash? You could gain additional income through the government’s Renewable Heat Incentive (RHI). Furthermore, you could also lower your home’s carbon emissions, depending on which fuel you are replacing. You won’t need to have any fuel deliveries and the GSHP can heat your home and your water with very little maintenance costs.

Air source heat pumps are usually easier to install than ground source heat pumps as they don’t need any trenches or drilling, but they can be less efficient. Water source heat pumps are another consideration. They can be used to provide heating in homes near rivers, streams, and lakes. It’s quite exciting to think about the potential of using naturally occurring resources to heat our homes and water.

You can find some stories from homeowners who have installed heat pumps via the Green Homes Network.

Size is an issue

Are wall-hung heat pumps the future of home heating systems?

Small homes and low energy homes are the challenge here as rural homes have utilised heat pumps for years. Rural homes often favour heat pumps over oil and liquefied petroleum gas due to the cost-saving benefits. One of the reasons why smaller homes are a technical challenge is due to space. Heat source pumps require quite a bit of outside space for the working unit. With many new build homes being built upon rather cramped plots, this may be problematic. These units can also require quite a bit of space on the inside of the home. For this reason, lots of companies are beginning to develop smaller, boiler sized units. This makes them handy for installing in flats as well as small houses. Excitingly, it also means that a number of these units in close proximity could be connected to the same bring loop, allowing for cheaper running costs for the homeowners.

We find the development of heat pumps pretty exciting, we hope you do too!

At Acre Design Newcastle we are passionate about all things green and would love to discuss your project with you in detail.

Take a look at our recent projects for further inspiration! Get in touch to arrange a free, no-obligation consultation at your home!

Wastewater Heat Recovery System


Thankfully, as a country we are becoming more and more environmentally conscious. As we know, it is critical to protect the environment so as to reduce the destruction of eco-systems. It is more of a moral obligation for humans to protect the environment from pollution and other activities that lead to environmental degradation.

Excitingly, lots of manufacturers now produce approved equipment that effectively recovers heat from your hot water before it runs away down your drain. This saves us both energy and money – a winning combination. None of us want to waste money. Certainly, most of us do not want to waste energy and will look for ways to be ‘greener’ wherever possible. When we take a bath or shower or use appliances such as dishwashers or washing machines, the hot water waste simple goes down our drain.

How does the system work?

A heat exchanger pipe is used inside the the waste water pipe. The heat eaxchanger pipe has cold water running through it. This could be installed under the shower tray, for example. Inside the heat exchanger pipe, the cold water will collect some of the heat from the waste warm water. This warmed up water then takes less energy to heat than it would had it been heated from cold. Your preheated water can be sent to your hot water cylinder, or it can be sent directly to the cold water feed on your mixer tap.

The devices are typically around 60% efficient, so they convert 60% of the potential energy in the waste water back into heat for the incoming water. This can save you money on your bills, especially if you use a lot of hot water in your home.

If your system is being used for bath water or for your washing machine or dishwasher, the process is a little different. In this instance, a storage vessel is required to hold the the warm water until the cold water runs through it to collect the heat. Though these systems can be less efficient than the exchanger pipe system, it will still have an impact. Unfortunately, they can often take up a bit of room (storing the waste water) too.

How is it installed?

Most wastewater heat recovery (WWHR) units are about 80mm thick, one metre long and simply look like thick pipes. Suiting an upstairs bathroom, they plumb in vertically. Alternatively, Showersave produce horizontal units which are suited to ground floor showers as they sit inside the shower tray and capture the warm water as it enters the drain. Installing a WWHR in your shower is a great place to start as the you generally have a pretty consistent stream of waste warm water.

What’s the cost?

At a cost of upwards of around £400 plus installation costs, they’re not the cheapest bits of kit. However, these systems have no running maintenance costs. The impact on your energy bill won’t be gigantic, however, the impact using less energy will have on our environment is important. In an average household, you could expect to save around £20-30 a year on your energy bill. Of course, if you use a lot of hot water, it can begin to look a lot more attractive. For hotels or other businesses that use an awful lot of hot water, it could be a great investment too.

Is it worth retrofitting one of these?

If you are not building a new extension or self-build and not renovating your bathroom or kitchen, is it worth retrofitting this equipment in your home anyway? In some cases retrofitting may be possible, but the bulk and length of the recovery device means that most showers or baths wouldn’t be suitable. It is much easier to get it installed when you are fitting a new bathroom.

Interesting fact: Most people believe having a shower is more energy efficient than having a bath. However, an eight minute power shower uses 136 litres of water, whereas the average bath uses just 80 litres in comparison. 

The Team @ Acre Design hope we have given you some food for thought! Please check out or latest projects if you’d like to see more of what we’re made of. Our InstagramPinterest and Facebook pages are all brimming with extension, loft conversion and self-build inspiration too!

Please contact us if you would like to arrange a free design consultation