Unless you have been hiding, you could not fail to realise that UK energy bills are at an unprecedented level. If we believe the press and general whisperings, then predictions are they will triple by 2023 reaching £5,000 for an average household.

These are indeed worrying times and it is no surprise that consumers are turning to low-energy solutions for daily tasks such as cooking, and drying clothes. Of course, the biggest outlay as we approach the UK winter is heating.

The economic crisis as well as greater emphasis on renewable energy to reach net zero emissions by 2050, has shone a light on alternatives to traditional energy with demand growing for solar panels, green roofs, and heat pumps.

With 190million heat pump units in operation worldwide in 2021, global sales increasing by 13% and The International Energy Agency’s latest report stating that no new gas boilers should be sold after 2025 we examine their growth, the advantages they bring to a residential project and what kind of investment they entail.

What are heat pumps?

In its most basic sense, a heat pump is a highly efficient energy device which takes heat or thermal energy from outside and moves it into your home using electricity. During warmer temperatures you can use some systems as a cooling device like air-conditioning.

The amount of power it uses is far less than the quantity of heat it provides, this is known as the Coefficient of Performance (CoP). If a heat pump has a CoP of 3.0 then it will give out three units of heat for every unit of electricity consumed.

Using existing heat means that it does not burn any fuel and therefore emit any carbon dioxide. It is for this reason that it is an incredibly efficient method of heating and has the potential to reduce energy bills.

What are the different types of heat pump?

There are two main types of heat pump available air source heat pumps (ASHP) and ground source heat pumps (GSHP).

Both work on the same principle to transfer heat but differ in the source of that heat. Which you choose depends on budget, installation, efficiencies, and your home.

• Air source heat pump

These are the most common system in the UK for domestic homes representing 87% of all heat pumps installed. You fit an air source heat pump (ASHP) to the outside of your home, either to the front, side or the rear (planning permission may be required).

With this system the heat from the external air is used to heat your home/hot water by pumping it through a system of refrigerant filled coils fitted to the outside of the unit (the evaporater), like those you find behind your fridge.

The liquid in the coils absorbs the heat and as it warms up begins to evaporate, this gas then goes through a compressor to increase the temperature. The coil then moves inside the building releasing the heat to inner coils which heat the house and/or water that supplies radiators, showers, taps etc. The refrigerant flows back outside to absorb more heat and the process begins again.

An air source heat pump can extract heat from temperatures as low as -15degrees Celsius to provide heating all year round.

There are two distinct types of air source heat pump (ASHP), air-to-air and air-to-water.

Air-to-air heat pumps: these take external heat and transfer to your home through fans or blowers. A warm air circulation system then moves it around your home.

They cannot heat hot water so you would need to look at an alternative such as an immersion heater. In the summer they work on reverse like an air conditioning unit.

They tend to be an excellent choice for smaller properties and are quick to install as they don’t require radiators or underfloor heating.

Air-to-water heat pumps: these take heat from the air outside and feed it into your water-based central heating system and your hot water cylinder to store hot water for when you need it.

As it has a lower heat supply than gas or oil boilers, 35degrees to 45 as opposed to 75degrees, an air-to-water heat pump is used most efficiently with large or double panel radiators or underfloor heating which have a greater surface area.

• Ground Source Heat Pump (GSHP)

These take heat energy from pipes beneath the ground outside your home to power your heating and hot water.

Thermal transfer fluid (TTF) or brine, a combination of cool water and antifreeze flows around the loop of pipe buried in the garden or outdoor area. The pipe absorbs the heat from the ground into this fluid which then passes through a heat exchanger into the heat pump. This action raises the temperature of the fluid and transfers the heat to water.

The ground stays at a constant temperature below the surface allowing the ground source heat pump to work efficiently all year.

You will need quite a large amount of garden or ground to use a GSHP.

What are the benefits of heat pumps?

It is hard to ignore the popularity of heat pumps particularly in their ability to reduce energy bills as well as lowering carbon footprint.

There are a variety of additional benefits that will no doubt see demand continue to grow, as they become an increasingly attractive alternative to gas boilers.

• Lower running costs –recent reports from the National Endowment for Science and the Arts (Nesta), state that a heat pump can reduce household gas consumption by up to 70% when compared to a gas boiler.
• Reduces carbon emissions – as heat pumps use little electricity, they produce no emissions making them environmentally-friendly. They are also extremely sustainable as they are using natural heat sources whether from the ground or air.
• Easy installation – it can take as little as two days to install an ASHP this might increase slightly with a GSHP due to the requirement to excavate slightly.
• Longevity – a modern heat pump usually has a life span double that of a domestic boiler, on average 20-25 years, future proofing your home both economically and environmentally.
• Less maintenance – they have very few moving parts, with yearly checks advised but they can be carried out by the owner such as clearing leaves, dust, and cleaning filters. A certified professional installer would need to visit every 3-5 years to look at any technical aspects.
• Safety – as they rely on renewables and electricity as opposed to fuel, and with few moving parts, they are a safer choice than traditional systems.
• Eligible for Government incentives –there are financial incentives for installing heat pumps which we will outline.

How much does a heat pump cost?

It can be expensive to install a heat pump, but this will depend on the type you choose, your installer, the size of your home, its insulation and running costs. A typical price for a full installation is between £7000 and £45,000.

Air to water heat pumps start at approx. £7000 reaching £18000, whereas ground source heat pumps can cost up to £45,000.

Although upfront costs are high, switching from your previous system should save you running costs in the long-term dependent on your tariff, which system you use, your home and its central heating system.

The Boiler Upgrade Scheme launched in England and Wales helps homeowners afford the upfront costs of installing low carbon heating systems such as heat pumps with grants of £5000 available. Open until the end of March 2025, the work must be carried out by an accredited MCS installer.

There are eligibility criteria including that you must own your home, and it needs an up-to-date Energy Performance Certificate (EPC).

Do I need planning permission for a heat pump?

Due to Permitted Development Rights, in most cases it is unlikely that you will need planning permission if installing a heat pump.

However, it is of course dependent on the property and the local planning department. This is especially important if the property is listed or within a conservation area.

You will have to inform your local district network operator (DNO) that you are installing a heat pump as they are responsible for bringing electricity from the network to your home. Your installer will advise on this.

Here at RISE Design Studio, we can help with any discussions you may need to have.

How an architect can help with a heat pump

Whilst most homes and residential projects will not require planning permission to install a heat pump, it is worth appointing an architect if you are keen to pursue it.

Whether you require planning or not, there are certain things to bear in mind should it be a retrofit, refurbishment, or new build project which may have other installations taking place:

• What will the aesthetic impact be with regards to an ASHP that fits to the side of your property?
• You will need to ensure no trees etc block its position
• Positioning of the ASHP will need to be in a sheltered spot
• A GSHP will require groundworks, these could be disruptive, so you want to ensure you carry these out correctly
• If you wish to install an underfloor heating system
  
  

As we continue to navigate this unchartered territory of rising energy costs, and we look to do more to achieve sustainability, the growth of alternative energy technologies such as heat pumps is no longer niche but rather an inevitable part of our future.

To get ahead and investigate whether heat pumps are right for your project, please do get in touch at mail@risedesignstudio.co.uk or give us a call on 020 3290 1003

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