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A lot of people in the UK worry that air source heat pumps might be noisy because of the fan in the outdoor unit. But are they really as loud as some think? To no one’s surprise, it depends. About three to four factors determine this: the type and size of the heat pump, and its placement.
Generally, an air source heat pump produces around 40 to 60 decibels (dB). For comparison, this is about the same as a light conversation, a fridge humming, or soft rain.
How Noisy Are Air Source Heat Pumps?
Air source heat pumps are equipped with fans and a compressor which tend to have some noise but it is much quieter than people expect. On average, the noise level ranges from 40 to 60 decibels (dB). This is just as audible as a soft chat or even the sound of a fridge.
Most noise is produced during the operation of the outdoor unit’s compressor and fan when heat is needed in the house. Unlike water or ground-source heat pumps, air-source heat pumps are more noisy, but their noise levels are less than that of the majority of appliances in the household.
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What Does an Air Source Heat Pump Sound Like?
An air source heat pump makes a low, steady whirring sound when running. This sound is associated with the fan unit taking in air while the compressor executes its task of heating the system. If you’re interested in the different models and their noise levels, check out this guide on types of air source heat pumps.
The source of noise is comparable to that of microwaves or dishwashers, so it is not loud enough to be disturbing. Many models operate at around 54dB, which can be quite comparable to the sound produced by modern refrigerators or gas boilers.
While air-source heat pumps are the loudest of the three types, the noise remains low and is not very likely to be a disturbance.
How Noisy Are Water Source Heat Pumps?
Water source heat pumps are quieter than air source but louder than ground source heat pumps. They sit within the range of 40 to 50 dB. The main source of noise is the internal unit and water circulation.
How Noisy Are Heat Pumps? – Overview
| Heat Pump Type | Noise Level (dB) |
|---|---|
| Ground Source | 40 – 42 dB |
| Water Source | 40 – 50 dB |
| Air Source | 40 – 60 dB |
Are Air Source Heat Pumps as Noisy as Ground Source?
Not really, air source heat pumps tend to be a bit noisier than ground sources. Those range from 60 dB when the machinery is working at full power. Ground source systems remain at a soft 40 to 42 dB meaning air source heat pumps can reach up to 60 dB.
Traffic and everyday conversations produce around the same noise levels and while a significant amount of disturbance can be expected, proper placement and installation of the heat pumps can drastically lower the noise.
Can You Hear Your Heat Pump from Indoors?
You will not usually hear your heat pump from inside in most cases. If, nevertheless, a window is open near the area where the heat pump is situated, you might be capable of catching a glimpse of the sound.
But even then, it will not be loud enough to cause any real discomfort. For the greatest part, heat pumps blend into the background, and you will most likely forget that it is even operating.
How Does This Noise Compare to Boiler Noise?
Both heat pumps and boilers come with a noise level of between 40-60 decibels(dB). In any case, you will probably be able to hear the noise from the boiler as it is situated indoors, mostly in the kitchen or utility room.
Since heat pumps are installed outside, the little noise they produce is less likely to be noticed. So, even when the heat pump is running and you are indoors, you are most likely not going to hear anything from the machine.
Where Is the Best Place to Put a Heat Pump to Reduce Noise?
For air source heat pumps, the best position is near your home but in a way that minimizes the noise effect. The recommendations are:
- Do not place it too close to your neighbours—especially in terrace houses, flats, or semi-detached houses.
- Use a hedge or a fence as a sound barrier.
- Do not put it in a corner, as walls can reflect sound and make it seem louder.
- If there is less space, notify your neighbours beforehand for installation to prevent any problems.
Are Air Source Heat Pumps Noisy for Neighbours?
No, air-source heat pumps aren’t noisy enough to bother your neighbours. UK law stipulates that the highest amount of noise is 42 decibels (dB) when recorded at the nearest neighbouring home, which is roughly as loud as a fridge running.
Even now, when your neighbors are on their balcony or in their garden, your heat pump will be extremely quiet, so much so that it is invisible. Just like how you can’t hear the hum of your own refrigerator, your neighbors will remain untroubled from the running unit.
Regulations for Noise from Heat Pumps 2025
Since April 2021, the noise level for air source heat pumps in the UK has been restricted, along with some other rules. The most important of these rules is that heat pumps cannot exceed 42 dB while being measured from the border of the neighbor’s properties.
If there are any uncertainties regarding noise rules in your local area, it is best to consult with the local authorities as rules may differ from one region to another.
Are Heat Pumps Noisier in the Winter?
Yes, as you might have suspected, heating and cooling pumps can in fact be a bit noisier during the winter season. The reason is that heat pump systems have to work rather more than usual to extract heat out of the cold air. In particular, air source heat pumps may be especially noisy during winter months simply because the temperature is routinely at 0° C or even beneath.
These systems can function normally at -25 degrees Celsius. On the other hand, water and ground source heat pumps remain quieter because the ground and water are warmer in winter than the air. However, they still have some noise differences compared to the higher temperature sources.
How Can You Make Your Heat Pump Quieter?
There are a number of tactics you can use to achieve sound dampening. Most of the fixes are DIY and do not require any professionals to meddle.
- Choose the Right Location: If the outdoor portion of your system is placed away from you and your neighbors, then it will cause less disturbance. Avoid corners where noise can bounce off walls.
- Buy a Quieter Model: While heat pumps tend to stick below 42 dB, some models are designed to be quieter than that.
- Use Soundproofing: To conceal the noise, you can put acoustic covers or barriers around the unit, although a bit pricey, sometimes costing over £1,000.
- Regular Maintenance: Make sure to check your heat pump regularly to help it keep in good shape. If the unit is regularly maintained, it will work and produce noise more smoothly.
- Don’t Overwork It: Overworking the heat pump will make the device noisier. If it is too small for your house, it will have to run harder to achieve the desired temperature.
- Improved Home Insulation: Good home insulation makes the house warmer enabling the heat pump to work less. Similarly, double or triple-glazed windows aid in restricting outside noise.
All in all, while you cannot completely mute a heat pump, the above-mentioned techniques will ensure that the noise won’t annoy you.
The Bottom Line
If you need to heat your house in an environmentally friendly way, heat pumps are a perfect solution as they use less energy compared to other systems. Though they do generate noise, it is considerably less compared to other home appliances.
Though both air-source heat pumps are quieter than the majority of home appliances, air-sourced ones are slightly noisier compared to ground-sourced ones.
With good installation and proper insulation, it is quite easy to minimise noise even with regular maintenance. There are noiseless models also available in the market, so you don’t have to worry about noise pollution even if you live in a quiet neighborhood or have close neighbors.
Frequently Asked Questions
Yes, heat pumps are generally quieter than boilers. Ground source heat pumps are usually the quietest option, followed by water and air source models. Boilers, on the other hand, produce more noise—mainly from the burner and flue exhaust. While heat pumps make a soft whirring sound when running, it’s often less noticeable than the noise from a typical boiler.
Yes. A heat pump does make some noise,- such as a low hum. However, if the sound is overly loud and causes a disturbance, it might need repairs from a professional.
You can limit disturbances by selecting an appropriate location for the heat pump, regularly servicing the unit, and ensuring that the structure of the house is well insulated.
No. Not all the time. Sometimes they do, but only while running. Mostly, they are quiet. You might experience slight noises when the system is turned on or off. However, this should stop almost immediately and is only brief.
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