Heat pumps: what you need to know

Article

Heat pumps are an energy efficient, low carbon way to heat your home. They are suitable for many types of home, you’ll get a £7,500 government grant to cover the supply/installation costs, and it could save you money on your energy bills. If you’re keen to have a heat pump in your home, here are some things you will need to consider before having one installed. And don’t worry, your installer will visit your home before having a heat pump installed to advise you on these points, and design a heating system that works for your needs.

The type of heat pump

The type of heat pump that suits you and your home can usually be determined based on your budget and how much space you have. There are two types of heat pump – air source and ground source.

Air source heat pumps are the most common for domestic use. You will need to find space for the heat pump externally; usually around 1 or 2 m² in your rear garden, though above flat roofs are possible as well as to the side elevation of your home, if there’s space. Your surveyor will lend a hand with choosing the right location.

A ground source heat pump requires a large amount of outdoor space, with good access. It will need underground pipes or boreholes to extract the energy from the ground, generally making them more expensive to install.

For all heat pumps you need space for a hot water cylinder or a thermal battery inside the house. An airing cupboard is ideal, unused utility room space, or to the rear of a garage, although other locations around the home are possible too.

Underfloor heating and radiators

If you already have a wet underfloor heating system, this works well with a heat pump. Underfloor heating, however, is not essential.

You may need to consider switching out your radiators to those with a larger surface area, which are more suited to heat pump systems. The larger the surface area, the more heat can be emitted which is important because heat pumps run more efficiently at lower flow temperatures. This is not always the case – you could run your heat pump at a higher temperature and retain the same radiators you have… but your bills will be slightly higher.

Radiators with larger surface areas don’t necessarily have to take up more space. Radiators can be upgraded from single to double or triple panels to increase the surface area without taking up extra wall space.

Why do they need a larger surface area? To allow more heat into the room without needing to increase the water temperature flowing through them. This is why the large surface areas of underfloor heating works well with a heat pump too.

Some homes built from the early 1970s onwards may have thinner pipework in radiators which is less likely to be compatible with a heat pump. It’s known as ‘microbore’ pipework and has a diameter of 12mm or less. Your installer – when they come to survey – will see if this is an issue and advise if it needs replacing.

Heat pump efficiency

Heat pumps are more efficient than other heating systems and should generate around three more times heat energy than the electricity they use.

Each manufacturer provides a datasheet telling you the efficiency, known as the coefficient of performance, or CoP. However, this could vary depending on external temperatures and changes throughout the year – the seasonal CoP, or SCoP. This will also vary depending on system design and flow temperature, which is bespoke to your home.

Your installer will calculate this for you based on the system design for your home, which will give you a better idea of the running costs before you go ahead with installation.

Installation costs

The costs to install a heat pump depend on which type you are installing. We’re careful at Toasty to assess your home to see if it’s possible to install a heat pump with no other finance needed other than the Boiler Upgrade Scheme grant. Take our heat pump readiness test to see if an air source heat pump may be suitable for your home. It’ll take about 2 minutes.

Ground source heat pumps have much higher installation costs than air source heat pumps, and it would be tricky to provide an accurate estimate here as the variables can be significant. Let’s say anywhere between £15,000 and £50,000!

Insulation

Heat pumps work better in well insulated homes. However, your home does not need to be fully insulated for a heat pump to work. Before installation, our installers will calculate your home’s heat loss, and therefore the likely size of the heat pump. Improving the insulation of your home will reduce your heating costs, however, in some homes upgrading the insulation may not be cost-effective.

Whilst the Government announced in March 2023 that homes do not need to have cavity wall or loft insulation to secure the £7,500 grant towards the installation cost, we still absolutely recommend this work is carried out before you get a heat pump. Toasty works with local partner schemes for insulation and can point you in the right direction to get that done too.

Planning permission

The good news is you probably don’t need planning permission to install a heat pump, however it is always good to get this checked to avoid problems down the line – who wants that!

Timing

It can take several months from start to finish to have a heat pump installed. The reasons for this are too many to mention here. However, with the launch of Toasty, having a heat pump installed through us can significantly speed up the process. That journey starts here.

There are a small number of things simply outside our control, and the installer’s control, that you need to be aware of. Firstly – the network. The installer will need to notify your local electricity network of the intent to install a heat pump. They undertake checks to make sure there is enough juice to serve the property. This is getting much quicker than it used to be, but you should expect a couple of weeks’ delay whilst that happens.

Secondly, you. You need to know this is right, so take your time in making the decision, don’t rush, and make sure you’re happy to proceed. If you’re unsure about anything, ask the question. You’ll find a bunch of useful information here, but your installer will also help. We will never rush you into making a decision.

Regarding the time it takes to actually install the heat pump itself, this is typically between three and five days.

To find out more about how Toasty can help you become heat pump ready, head to: https://www.toasty.org.uk/learn-more/

Noise

Don’t worry, installed in the right place, a heat pump won’t attract complaints from your neighbours! Research suggests they produce a similar noise level to that of a fridge or gas boiler, meaning you could hold a normal conversation standing next to one. We have more information on noise in this article.

Installation

There will be some disruption when having a heat pump installed. Work may include building a plinth outside for a heat pump to stand on, installing new pipework, replacing or installing a hot water cylinder and upgrading radiators. However, your installer will keep disruption to a minimum.

To find out more about how Toasty can help you become heat pump ready, head to: https://www.toasty.org.uk/learn-more.