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Air source heat pumps are noisy, but you can take steps to minimize the noise. Problems are mostly due to where and how the unit is installed.
Hopefully, you’re reading this article before you’ve installed the heat pump. But don’t despair – we also have tips on what to do if your unit is making too much noise right now.
What Kind Of Noise Do Air Source Heat Pumps Make?
The manufacturers and resellers may try to bamboozle you with decibels and such. But I went straight to the horse’s mouth!
I consulted several house owners with air source heat pumps and asked them about the noise. Here are a few descriptions.
It’s kind of a deep droning sound.
I get some mechanical noise.
It’s mostly a reverberating sound.
Some of the householders mentioned that they mostly head the noise in one room or area of the house. Yet, they hardly noticed it when outside.
The householders who most noticed the noise also said their unit was wall-mounted. Some had plans to move the pump. Read on for their tips and advice.
But first, we’ll quickly look at why these pumps make noise.
Why Air Source Heat Pumps Make Noise
The noisiest parts of an air source heat pump are the fan, the compressor, and sometimes the piping.
The fan
Air makes a sound when it passes through the fan. How much depends on the speed of the model.
Due to noise regulations, manufacturers continue to work on designs that reduce the decibels produced.
The compressor
The compressor can be noisier than the fan, but the circumstances are more rare.
Occasionally, you may have to run the compressor in reverse to get rid of frost in the unit. This can be a noisy operation, but thankfully it shouldn’t be too common.
The piping
This is something that the manufacturers rarely mention, but it cropped up quite a lot when I was checking with householders.
It’s the pipes that can transfer noise into your house from the unit outside. This tends to be the “mechanical” noise that some people mention.
We have some piping tips for you in a later section.
How Loud Do Air Source Heat Pumps Get?
One householder who replaced an oil-fired boiler with an air source heat pump reported that the noise was pretty much the same.
However, because the heat pump was outside the house, the owner was very happy with the change.
These heat pumps used to be a lot noisier. But as complaints started rolling into urban councils and administration, noise legislation was introduced in many regions.
You can find more details about noise regulations in the United States here.
Whatever about your own sensitivity, you must be mindful of your neighbors.
Due to these concerns, manufacturers had to innovate with the design of the fans to reduce the noise.
How noisy are air source heat pumps?
Different models produce different levels of sound. You can expect a level of about 50 decibels.
Of course, some models will be louder than others. You should check the manufacturer’s specifications to get the details of your chosen model.
In general, the larger the heat pump, the more noise it’s going to make.
To put this into context, the hum from the refrigerator in your kitchen is about 50 decibels. An electric toothbrush is about 10 decibels higher.
Best Way To Mount Your Unit To Minimize Noise
The householders most likely to mention noise were the ones who had wall-mounted units like this:
One man said his walls were two feet thick! But he could still hear noise inside the house from his wall-mounted unit.
The better choice is a ground-mounted installation a few meters from the house.
The challenge is that insulated underground piping can get expensive. But if you’re sensitive to background sound, it could be worth it.
Where To Place Your Air Source Heat Pump To Reduce Noise
I mentioned that some householders only heard the noise in a particular room.
One satisfied customer could only hear noise in their utility room. That’s because they had carefully sited the ground-mounted unit so it would only affect that area.
In contrast, a more frustrated owner said that the unit was outside his living room. He was at pains to say he wouldn’t recommend this choice!
Best tips for placement
Try to avoid placing the unit outside a bedroom or living room wall.
Try to ensure your heat pump is not facing a window.
This one may be a little too close for comfort:
Some folks have a split system with part of it inside the house. If you didn’t think that was possible, check out our article on whether air source heat pumps can be indoors.
Tips For Ensuring Pipes Don’t Increase The Noise
Why do owners of air source heat pumps report that they hear more noise inside the house than they do outside?
This is usually because the noise is being transmitted inside by the pipes.
Some owners use flexi pipes to solve this problem. The flexibility reduces vibration transfer into the house.
