Heat Pumps: Air to Water vs Air to Air

Air source heat pumps are a great way to reduce your dependence on a gas boiler or electric heaters. They fall into two main categories – air to water and air to air heat pumps – each of which has its own advantages. Read on as we take a closer look…

What is an air to water heat pump?

An air to water heat pump is the most popular type of air source heat pump. It works by extracting heat from the air outside your home, which warms a refrigerant liquid – turning it into a gas. The refrigerant vapour passes through a compressor which increases the pressure and generates more heat.

The hot, compressed gas passes into a heat exchanger, which heats the water around it. This hot water can then be used in your home – in the radiators, taps, shower or even underfloor heating.

What about air to air?

An air to air heat pump works in the same way as its air to water counterpart, except that the heat exchanger warms up air around it rather than water. That warm air is then distributed in your home through blowers or fan units.

Unfortunately, that means an air to air heat pump can’t be used for hot water in showers, taps, radiators and underfloor heating. Instead, they are solely used for heating spaces with warm air.

Comparing the two

Size

Because they’re only used for heating rather than hot water, air to air heat pumps are generally smaller than their air to water counterparts. While you may need to account for the size of indoor units which distribute heat, this is usually cancelled out if you can have radiators removed.

That said, it’s worth noting that you’ll still need a space-consuming conventional boiler to supplement an air to air heat pump, whereas an air to water heat pump can work as a standalone heating source.

Efficacy

The warm air produced by an air to air system can heat up a space quicker than most radiators, although it does interfere with humidity levels in doing so. While they may be superior in this sense, the inability to heat water does make them a less effective option overall.

Cost

In terms of cost, an air to water heat pump will set you back more than an air to air system. That’s understandable given that it does far more for your property.

However, because they’re capable of providing all your heating and hot water, air to water heat pumps are eligible for the Boiler Upgrade Scheme. That means you could be eligible for a grant of £5,000 towards the cost, which would make the price roughly level with that of an air to air heat pump.

The verdict

If you’re looking for a renewable heating system to work alongside a conventional gas boiler, an air to air heat pump could be a good fit. However, as a long-term replacement for your gas boiler, it has to be an air to water heat pump.

If you would like any more information about air to water heat pumps, speak to the team at COA Services. As MCS-certified air source heat pump installers in Leeds, we can answer any questions you may have and arrange a free, no obligation quote if needed.

Email [email protected] or call 01423 408 336 to get started.