Are all heat pumps noisy? I had one for a week and it drove me crazy

I have just returned from a holiday where we stayed in a French house by the beach that had a heat pump.

The heat pump was in the back garden and seemed to be on a lot, and almost constantly at night, producing a low level but intrusive fan sound, like the ducting at the back of a restaurant.

It was actually quite annoying if you were sitting outside during the day when it was on, but even more annoying to have the constant hum of the fan while you were eating dinner or sitting outside at night.

I’m probably more sensitive to noise than most people, but when I was expecting to hear the sound of the ocean and instead could hear a humming fan, I went crazy.

I had been thinking about installing a heat pump at home, but this has put me off. Are all heat pumps noisy? Is there anything I can do to minimise this? LS

This is Money’s Sam Barker responds: Heat pumps have clear advantages when it comes to producing greener electricity, but even the most ardent heat pump enthusiasts must admit that they do have some potential drawbacks, and one of them is noise.

Technically, I’m referring to noise plus location. The average combi boiler is about as loud as a typical heat pump hums – around 40 to 60 dB.

At the low end of the scale, the volume is about that of birdsong or a microwave, and at the high end of the scale it is as loud as a typical conversation.

The problem is that most boilers are located in out-of-the-way places, such as an airing cupboard, while air source heat pumps tend to be located on the exterior walls of homes.

This can mean that the perceived noise of heat pumps may be more annoying, depending on where you are located in relation to the pump.

That noise can also increase if a heat pump is not properly maintained or during cold weather, when it has to work harder.

If a heat pump is located near a bedroom window, for example, it could become quite a bothersome noise.

Alternatively, if you sit outside, close to where the heat pump is, you will certainly notice it.

As you may have noticed during your holidays, the human ear can perceive very noticeable and quite annoying low humming noises.

The average air source heat pump produces sound in the 50 to 100 Hz range, right in the middle of the low frequency range, which tends to carry the farthest.

Think about how you can hear the bass of a live band even from a distance, or how the low rumble of a big diesel engine idling is heard farther away than other engine noises.

UK law states that the volume of a heat pump cannot exceed 42 dB at the boundary of the property in which it is installed.

Local authorities receive complaints about noise related to heat pumps, although these are currently rare.

Retirement group Saga found this month that half of the councils surveyed (124) had no noise complaints, while just under half (117) received between one and ten. Only nine of those 117 had noise complaints about heat pumps reaching double figures.

It’s fair to assume that complaints about heat pump noise will increase, as the Government wants UK homes to be fitted with 600,000 heat pumps a year by 2028.

It is clear to everyone that the government considers it highly unlikely that this target will be achieved, as only 55,000 heat pumps were installed last year.

But still, more heat pumps mean more noise complaints. So, if you’re thinking about getting a heat pump, there are some steps you can take to make sure it doesn’t bother you or your neighbors.

How can you make your heat pump quieter?

The obvious solution is to locate the air source heat pump’s outdoor unit somewhere where it will not be obtrusive.

Another obvious measure is to buy a quieter heat pump. The industry is working to bring quieter units to market, but currently none of the top five heat pump companies make devices quieter than 42 dB, according to government figures.

This means that realistically any heat pump you purchase will make a sound equivalent to a bird’s chirping, which might be enough to be noticeable.

A ground source heat pump will be quieter, but also more expensive to install, and many properties do not have the necessary outdoor space.

A more effective but expensive option is to soundproof the external heat pump unit.

This will reduce the noise it emits to the outside world, but it can cost upwards of £1000 to install correctly and will increase the size of the space the heat pump takes up.

Hopefully, this will help you put the volume of heat pumps into perspective and help you draw the right conclusions for you and your living situation.