As more and more UK homes look to convert to low-carbon heating, air-source heat pumps (ASHPs) are gaining popularity. Yet, there is one question usually asked before doing so: Are air-source heat pumps noisy?
If you’ve been wondering whether a heat pump will disrupt your home’s peace—or annoy your neighbours—you’re not alone. In this blog, we’ll break down the facts about air source heat pump noise levels, causes of loud units, and practical solutions to keep your heating system quiet.
Does a Heat Pump Make a Noise? Understanding Basic Operation
Yes, heat pumps are noisy, as any appliance with a fan and compressor. The majority of the noise originates from the outside unit, where air is sucked in and compressed to facilitate heat transfer. The indoor unit is typically very quiet, often quieter than a refrigerator.
The key thing to understand is that while all heat pumps make noise, most models today are designed to be as quiet as possible. When installed properly, they shouldn’t cause disturbance.
How Much Noise Does an Air Source Heat Pump Make? Typical Sound Levels
On average, air source heat pumps produce between 40 and 60 decibels at a distance of one meter. That’s comparable to:
- 40 dB – a quiet library
- 50 dB – light rainfall
- 60 dB – normal conversation
To help visualise this, many installers and manufacturers provide a heat pump noise chart showing sound levels by brand and distance.
It’s also helpful to look at your model’s rating on a heat pump noise complaints chart, comparing sound output during various weather and usage scenarios.
To help you visualise how loud a heat pump is, here’s a simple noise comparison chart:
Heat Pump Noise Chart: How Loud Are They?
It is easier to understand how noisy a heat pump is with a simple comparison. Following is a heat pump noise chart indicating typical air source heat pump noise levels in decibels (dB) and comparing them with some familiar household sounds:
| Noise Source | Decibel Level (dB) | Example/Notes |
| Whisper | 30 dB | Very quiet |
| Library or quiet room | 40 dB | Comparable to the quietest heat pump models |
| Air Source Heat Pump (Quiet) | 40–45 dB | Mostly at 1m distance, low setting |
| Air Source Heat Pump (Standard) | 50–60 dB | Comparable to rainfall or background conversation |
| Normal conversation | 60 dB | Slightly louder than most ASHPs |
| Washing machine (mid-cycle) | 65 dB | Equivalent to louder heat pumps or poor placement |
| Vacuum cleaner | 70+ dB | Significantly louder than any efficient heat pump |
Tip: When shopping, always look for the manufacturer’s specification of noise level (check the Sound Power Level in dB(A)). It can prevent you from complaining about heat pump noise in the future.
How to Use This Chart
- Compare the rating of your present heat pump to the chart.
- Decide whether you prefer a quieter model or a better location.
- Refer to it when discussing installation with an engineer.
Why Is My Air Source Heat Pump So Loud? Possible Causes
If your heat pump sounds louder than it needs to, something may be wrong. These are some of the most frequent causes:
- A heat pump is noisy during startup: It is normal to notice a low hum or click once the system is initialising.
- Loose panels or vibration: If the installation was not performed correctly, components can vibrate.
- Defrost mode: During cold weather, units briefly reverse to defrost ice. This can be slightly noisier.
- Ageing components: Older or poorly maintained heat pumps can get louder over time.
These are classic cases of heat pump troubleshooting noise scenarios—best handled by a professional.
Are Air Source Heat Pumps a Noise Nuisance? What Neighbours Should Know
A common concern is: Are heat pumps noisy for neighbours? In most cases, no, especially when the unit is installed with proper spacing and sound levels in mind.
In the UK, permitted development rules generally allow ASHPs as long as they don’t exceed 42 dB at the nearest neighbour’s boundary. To remain in compliance and prevent heat pump noise complaints, the installer must carefully plan the unit’s placement to minimise noise.
It is always preferable to notify your neighbours beforehand about the installation and choose a quiet version, backed by a noise chart from the heat pump manufacturer.
What Affects the Noise of an Air Source Heat Pump?
A few things can influence how quiet or loud your system will be:
- Model configuration and construction quality
Top-of-the-line units often come equipped with excellent sound insulation and sound-reducing design features. - Installation and siting
A unit installed near a wall or hard surface will bounce and magnify noise. Professional installers avoid this. - Environmental factors
Wind, temperature, and nearby objects can all affect perceived noise. - Operating mode
Night-time settings are typically quieter. High-demand settings can be louder temporarily.
Considering these factors helps minimise unwanted sound and avoids future issues, such as heat pump noise complaints.
If you’re considering getting one installed, our step-by-step Air Source Heat Pump Installation Guide for 2025 explains how proper placement and setup can reduce potential noise issues right from the start.
Why Does My Heat Pump Get So Loud During Winter? Seasonal Factors
It’s normal to experience a temporary increase in noise level during colder months. The reason is that the unit has to work harder to pull heat out, and that defrost cycle may be a bit louder.
This isn’t a sign that your system is faulty—it’s just a normal part of the process. However, if it’s continuous or significantly louder than normal, then it may be time to turn to heat pump noise troubleshooting tips or contact an engineer.
How to Minimise or Avoid Heat Pump Noise
Here’s how you can make your air source heat pump as quiet as it can be:
- Select a quiet model
For certified Quiet Mark units or low-decibel ratings on a noise chart for heat pumps. - Correct installation
Professional installation and anti-vibration mounts can significantly reduce noise. - Sound barriers installed
Fences, trellises, or horticultural screens can dampen noise, as long as airflow is not restricted. - Regular upkeep
Yearly tune-up keeps your system operating quietly and efficiently.
By doing this, you can avoid heat pump noise complaints and enjoy a neighbourly heating system.
FAQ’S
No, they primarily make a low hum while in operation. Noise is likely to increase when starting up or in freezing temperatures.
Usually about 40–60 dB, roughly the same as a refrigerator or a quiet conversation. Refer to the heat pump noise chart for precise information.
It’s standard. The heat pump is noisy when it starts up because of the operation of the fan and compressor.
Rarely, if it was well installed, UK law restricts sound to 42 dB at the boundary of the property.
Poor installation, loose components, or defrost mode can make it noisier. Attempt heat pump noise testing if in doubt.
Yes. Select quiet models, utilize anti-vibration mounts, install barriers, and perform regular maintenance to minimize noise.
At times. Sudden or persistent loud noise may require investigation to prevent more sinister issues.
