A Guide to Hybrid Air Source Heat Pumps

air source heat pumps

As the UK looks for greener solutions to heating our homes, the need to replace gas-powered boilers is growing. Leading the charge are hybrid air source heat pumps, which have grown in popularity over the past few years.

But what exactly are hybrid air source heat pumps, and how do they work to make UK homes greener? To help answer this, we’ve put together a comprehensive guide on everything you need to know about hybrid air source heat pumps.

Air source heat pump in the snow

Hybrid air source heat pumps work effectively in the cold

How does a hybrid air source heat pump work?

 

Before we explain what a hybrid air source heat pump is, first a brief overview of ordinary air source heat pumps.

Whereas most home heating systems use fuel or convert electricity to heat a home, an air source heat pump works using only the air outside. By drawing in air from the outside and then converting it into heat, an air source heat pump works functionally the same as more traditional home-heating methods.

This includes heating your water, so rest assured you’ll still be able to enjoy a hot shower!

The best part about air source heat pumps is that they don’t need warm air outside in order to function. In fact, many heat pumps are capable of warming homes with outside air temperatures as low as -20°C (-4°F). This means air source heat pumps are completely viable in colder climates, because even in sub-zero temperatures, there is still heat in the air.

A hybrid air source heat pump works in much the same way, only it combines both an air source heat pump and a standard boiler to heat your home.

This way, you still get the environmental benefits of using air to heat your home, with the backup of a gas-fired boiler in case the air outside becomes too cold to convert to heat efficiently. In essence, a hybrid air source heat pump is perfect for milder climates with colder winters.

ProsCons
  • Works efficiently all year round in colder regions
  • Can use gas as a backup in winter
  • Provides clean home heating when outside temperature is optimal
  • Ideal for poorly insulated homes where a purely air-powered heat pump wouldn’t work efficiently 
  • Low maintenance 
  • Reduces carbon footprint
  • Helps reduce gas and oil consumption
  • Longer life than traditional boilers
  • Lowers energy bills 
  • Still reliant on fossil fuels, albeit less so 
  • Higher upfront cost than standard boilers
  • Costly installation process, complicated by things like pipework location
  • New technology; low adoption rate at present
  • Currently limited numbers of experienced technicians 

Should you get a hybrid heat pump or a normal one?

 

Whether you choose to get a hybrid heat pump or a normal one depends entirely on your circumstances – including where you live, which we’ve mentioned briefly above. Because most air source heat pumps only heat homes up to around 40-45°C (104-113°F), older, more poorly insulated homes will struggle to keep warmth efficiently.

This is especially true when the temperatures outside drop below a certain threshold, because as it gets colder, air source heat pumps become less efficient. Sure, many heat pumps can continue to work in freezing temperatures, but the cold makes heating radiators far more difficult.

It’s not helped either by the fact that many homes have smaller radiators designed for traditional gas-fired boilers. An air source heat pump requires larger radiators to distribute heat more efficiently; smaller radiators simply don’t work as well.

The advantage of a hybrid heat pump, then, is the ability to fall back on a gas-powered boiler when the conditions don’t allow an air heat pump to generate enough warmth.

They’re also an excellent stepping stone towards net zero, at least until technology improves to a point where non-hybrid heat pumps work efficiently in sub-optimal conditions.

If you live in an area where a normal heat pump will work well throughout the year, take a look at our list of the best air source heat pumps available on the market right now.

How an Air Source Heat Pump Works

An overview of how a heat pump works

How much does a hybrid air source heat pump cost?

 

The upfront costs of a hybrid air source heat pump are higher than those of a traditional boiler, as the technology is still new. Installation costs are also higher, as there are fewer qualified technicians able to install them.

As for the units themselves, the costs range anywhere between £5,000-£10,000 (compared to the average cost of a boiler unit – £2,500-£4,000). Some might balk at these costs initially, but that’s without understanding the potential savings associated with a hybrid air source heat pump. These savings become substantial when you look at the bigger picture:

  • A hybrid air source heat pump will last far longer than a standard boiler – 10-15 years for a boiler compared to 20-25 for a hybrid air source heat pump!
  • If you’re in the United Kingdom, you can earn money through the government’s Renewable Heat Incentive (RHI) scheme (please note, the RHI scheme will be replaced by the Clean Heat Grant (CHG) in April 2022).
  • You will use and pay for far less fuel with a hybrid heat pump.

In addition, the size of your home will determine the power of the unit you need, which of course impacts the cost.

A bigger home requires a higher-capacity pump to warm the property efficiently. There are positive moves from the government however, with a recently announced £5,000 grant for home heat pumps that should help more people adopt the technology.

Here’s a helpful chart showing the cost of running a standard gas boiler compared to a hybrid air source heat pump over 15 years (based on a semi-detached property occupied by two people):

What’s the best hybrid air source heat pump?


As the technology is still quite new, the hybrid air source heat pumps available on the market are limited when compared to the plethora of boilers for sale. What is good though, is that many of the best-known boiler manufacturers have started selling hybrid air pumps, combining their boiler expertise with the new technology.

Take a look at the table below for our pick of the best hybrid air source heat pumps currently available on the market:

Manufacturer ModelCost (approximate)
ValiantaroTHERM hybrid air source heat pump (5kW, 8kW, 11kW, 15kW)£5,900-£8,500
GrantAerona³ R32 air source heat pump£2,650-£5,350
Daikin5kW or 8kW Altherma heat pump£3,750-£4,200

How long do they take to install?

 

The process of installing a hybrid air source heat pump can differ according to your home’s heating setup.

For example, your pipework could be in an optimal location, which would make the installation process quicker (likelier in newer properties).

However, if the pipework is not in the right location, then it’s likely that you’d need to have new piping installed to accommodate the heat pump. This is more likely in older properties, which were designed around older forms of home heating.

Space is something you need to think about too. A hybrid air source heat pump will require space outside the property, with the pump mounted either onto a wall or positioned on the ground.

Just remember that having space for the unit is not enough; you will also have to make sure there is clearance around the heat pump so it can work properly. Wall-mounted pumps need around 200 mm as a minimum to function efficiently, whereas ground units tend to need a little more space.

Do they require much maintenance?

 

In most cases, hybrid air source heat pumps are low maintenance and don’t require the comparatively frequent repairs needed for standard boilers. This is because the hybrid aspect means that the boiler is used far less, which has the obvious effect of reducing wear and tear on the unit. A high-quality hybrid heat pump can last between 20-30 years, though it’s still advisable to get a checkup every year or so.

Despite this, there are still a few things you should do throughout the lifespan of your hybrid heat pump. These include:

  • Checking the filters, coils, and fans and either cleaning or swapping them if necessary
  • Making sure airflow isn’t hindered by leaves or other debris
  • Keeping an eye on whether the heat pump is leaking (heat pumps collect and store condensation from the air that must be emptied every now and then)

Even considering the above, the essential parts of a hybrid air source heat pump are far less likely to degrade than those of a standard boiler.

Next steps

 

With the government ban on boilers in new builds coming in 2025, and the ban on all boilers coming in 2035, now is the time to consider a hybrid air source heat pump. They’re the perfect starting point for those looking to reduce their carbon footprint, without the worry of dropping a standard boiler entirely.

Tom Gill Writer

Tom is a big fan of all things eco and has a passionate interest in how technology and localised projects can work together to make the world greener.

Back to Top