Why Air Source Heat Pumps are Not a Viable Option Instead of Boiler Installations in London

Air source heat pumps have become somewhat of a hot topic since the Mayor of London announced the government’s plans to become a net carbon city by 2030. The Mayor believes this can be achieved by retrofitting and installing 120,000 heat pumps per year in London.

However, many heating experts have cast doubts on heat pump installations in London and beyond. Despite the many environmental benefits heat pumps offer, there are also a wide range of disadvantages of using heat pumps, especially in urban locations, such as London.

Here we will explore everything you need to know about air source heat pumps and why air source pumps are a less viable option than boilers in London and other urban areas.

What is an Air Source Heat Pump?

An air source heat pump is a heating system that uses renewable energy to warm homes. This type of heat pump works by absorbing air from the outside and heating it with the help of a liquid refrigerant and a compressor.

After it has been compressed, the hot air will liquefy before being pumped into a property to heat radiators and underfloor heating. The rest of the hot water will typically be stored in a hot water cylinder for taps, showers or baths.

What Are The Disadvantages Of a Heat Pump?

Air source heat pumps can be beneficial to the environment. However, they also come with a range of downsides, including:

  • They require a significant amount of outdoor space
  • Condenser units are noisy
  • The upfront costs range from £7000 to £10,0000
  • They are not 100% zero-carbon as they use electricity
  • They reply on temperature, so are not as efficient in colder temperature

Can Heat Pumps Be Used Anywhere?

Air source heat pumps must be placed outside, and they need plenty of air around them to circulate, so they may not be ideal for properties with limited outdoor space.

Heat pumps can be installed outside almost any home. However, there are some planning permission restrictions that may affect whether you can install or retrofit a heat pump. An air source heat pump installation is classified as a permitted development if it adheres to the following requirements:

  • Only first-time installations are permitted
  • There are no existing wind turbines on the property
  • The installation complies with the Microgeneration Certification Scheme Planning Standards
  • The volume of the outdoor compressor does not exceed 0.6 cubic metres
  • It is at least one metre from the property boundary
  • The property is not a Listed Building or Scheduled Monument
  • It is not installed within a Conservation Area or World Heritage Site
  • It must not be installed on a wall in front of a highway

If the installation does not comply with the current regulations, planning permission will be required before fitting an air source heat pump.

Are Heat Pumps Suitable For All Houses In London?

No, not all heat pumps are suited to every home in London. This is because a lot of properties in London do not have enough space for an air source heat pump installation. In fact, even houses that have yard space are limited, as gardens in London are actually 26% smaller than the national average.

Air source heat pumps are available in various sizes, so you should check whether you have the correct amount of space before investing in one. The size of air source heat pumps is typically measured by the air source heat pump (ASHP) output will also determine the amount of heat that is generated. For example, a smaller 5kW air source heat pump may not be suitable for a larger home.

The level of insulation will also affect the size you choose. For instance, If you live in a poorly insulated four-bedroom property in London and have the space to install an air source heat pump, you will have to invest in a 16kW (ASHP output) to ensure your home is heated efficiently.

Can I Replace a Gas Boiler With An Air Source Heat Pump?

Replacing a gas boiler with an air source heat pump is viable, as long as you have space to install an air source heat pump. The latter will take up a lot more room than, say, a system gas boiler, as they tend to be much more compact.

You also need to factor in the change in fuel, as air source heat pumps are powered by electricity. Therefore you may need to add the cost of new electric radiators and pipework to the installation quote. This can actually increase the price up to £7000 if the job is complex.

You may also be wondering – are heat pumps cheaper to run than gas boilers? No, this is not the case. Air source heat pumps cost approximately 15 pence per kWh, whereas the running cost of a mains gas boiler is around 2.4 pence per kWh.

Can I Replace My Combi Boiler With a Heat Pump?

Yes, it is possible to replace a combi boiler with an air source heat pump. However, before doing this, you need to factor in the differences. For example, a combi boiler can provide instant hot water, which a heat pump cannot do.

You also need to compare the cost of replacing a combi boiler with an air source heat pump, as on average, installing an air source heat pump will cost £2000 more than a simple like-for-like combi boiler replacement.

Should I Replace My Boiler with a Heat Pump If I Live in London?

The short answer is no, especially if you live in London or an urban area, as the limited space will hinder you from installing the correct size heat pump.

A boiler is a more reliable heating option, as air source heat pumps rely on the temperature of outside air, which typically remains low in London for most of the year.

Boiler installations in London are also more affordable in terms of upfront costs. Modern boilers with smart thermostats are also far more efficient, which means you can actually reduce your carbon footprint while lowering your energy bills.

Final Thoughts!

Now that you have a better understanding of air source heat pumps and why they are not the better choice over boiler installations in London, you may want to consider upgrading your boiler to a more modern and efficient model. Will you opt for a compact combi boiler or maybe even a smart system boiler? The choice is yours!