Are Air Source Heat Pumps Noisy? No, Here’s Why
Are air source heat pumps noisy is a common concern for UK homeowners and landlords considering a switch to renewable heating in Southern England, Greater London, South West England, or South Wales. Modern ASHP outdoor units produce a low, steady hum similar to a fridge or dishwasher, with noise levels typically ranging from 40 to 60 decibels — well within UK regulations and rarely disruptive when properly sited and installed.
How Noisy Are Air Source Heat Pumps in Reality?
Air source heat pumps are not particularly noisy in reality, operating at sound levels comparable to everyday household appliances. Most modern outdoor units produce between 40 and 60 decibels (dB) at one metre, akin to a quiet conversation (50dB) or moderate rainfall.
To understand why modern units operate so quietly, it helps to understand at how air source heat pumps work, as inverter-driven compressors and variable-speed fans are designed to maintain steady output without sudden noise spikes.
Inside the home, the sound is usually inaudible or barely noticeable, as the main noise source is the external compressor and fan. In urban settings like Greater London or densely packed terraces in Brighton, careful placement ensures minimal impact on neighbours.
EE Renewables provides expert air source heat pump installation across Southern England, Greater London, South West England, and South Wales — including areas like London, Brighton, Oxford, Southampton, Bristol, and Cardiff.
Understanding Decibel Levels and Comparisons
To put ASHP noise into perspective:
- 40dB — Quiet library or gentle fridge hum
- 50dB — Normal conversation at home
- 60dB — Dishwasher or background office chatter
UK regulations under MCS 020 (and the updated MCS 020 a) cap permitted development installations at an effective limit ensuring no more than 42dB at the nearest neighbour’s habitable room window — a level most modern units meet comfortably.
What Do UK Noise Regulations Say About Air Source Heat Pumps?
UK noise regulations for air source heat pumps require that installations under permitted development do not exceed 42 decibels when measured one metre from the neighbour’s nearest habitable room window.
This standard, enforced through the Microgeneration Certification Scheme (MCS 020 a in England since 2025), includes a nominal background noise assumption and accounts for tonality.
The rule promotes widespread adoption while protecting residential peace, particularly in quieter areas of South Wales or rural Oxford.
Permitted Development and Noise Compliance
Most domestic ASHP installations qualify as permitted development without planning permission if they meet the 42dB limit. Exceeding this (rare with quality units) requires full planning consent. MCS-certified installers perform noise calculations during site surveys to guarantee compliance.
Which Air Source Heat Pump Brands and Models Are the Quietest?
The quietest air source heat pump brands and models in 2026 include Samsung (EHS Mono HT Quiet at as low as 35dB), Vaillant aroTHERM plus, and certain Mitsubishi units, often Quiet Mark certified for superior acoustic performance.
Quieter operation is often linked to advanced system design and overall heat pump efficiency, as efficient units avoid the constant high-load cycling that can increase sound levels over time.
These models use advanced inverter technology, sound-dampening materials, and quiet modes to minimise fan and compressor noise, ideal for noise-sensitive properties in Southampton or Cardiff.
Quiet Model Comparison (2026 Estimates)
| Brand/Model | Typical Sound Pressure Level (dB at 1m) | Key Quiet Features | Best For |
|---|---|---|---|
| Samsung EHS Mono HT Quiet | 35–50 dB | 4-step Quiet Mode, advanced insulation | Urban terraces in London/Brighton |
| Vaillant aroTHERM plus | 40–54 dB | Low-noise fan, Quiet Mark certified | Family homes in Oxford/Southampton |
| Mitsubishi (select models) | 45–55 dB | Inverter tech, durable low-vibration | Coastal properties in South Wales |
| Daikin Altherma | 50–60 dB | Sound-reducing design | Larger detached homes in Bristol |
Choosing a Quiet Mark certified unit ensures third-party verified low noise for peace of mind. While quieter models may have a higher upfront price, they often represent better long-term value when considering air source heat pump costs, as premium components typically deliver lower running costs, fewer maintenance issues, and improved lifespan.
How Can You Minimise Air Source Heat Pump Noise During Installation?
You can minimise air source heat pump noise during installation by selecting a quiet model, positioning the outdoor unit away from bedrooms and neighbours, using anti-vibration mounts, and adding acoustic enclosures if needed.
Site surveys by MCS installers assess airflow, reflections, and barriers like fences, which can reduce noise by 1-3dB. In high-density areas like Greater London, mounting on rubber pads and facing away from boundaries prevents vibration transfer.
Practical Noise Reduction Tips
- Install on solid ground with anti-vibration feet
- Use sound-absorbing barriers or plant screening
- Schedule operation on smart controls for off-peak/quiet modes
- Maintain the system regularly — routine servicing helps prevent vibration and rattling, and proper air source heat pump maintenance ensures fans, mounts, and internal components continue to operate quietly and efficiently.
What Should You Do If Noise Becomes an Issue After Installation?
If noise becomes an issue after installation, first check for simple fixes like cleaning the unit or adjusting settings, then contact your installer for a service check.
In rare cases of persistent disturbance, local councils handle statutory nuisance complaints, though evidence shows low incidence of valid ASHP noise issues when MCS standards are followed.
Pro tip: In some cases, excessive noise can be linked to incorrect system sizing, which is why understanding what size air source heat pump you need is essential to avoid overworked or inefficient operation.
Addressing Neighbour Concerns
Most complaints stem from poor siting or older models. Proactive communication with neighbours and professional assessments usually resolve concerns quickly.
Ready to Install a Quiet Air Source Heat Pump? Request Your Free Quote Today
Modern air source heat pumps are far quieter than many expect — and with the right model and installation, noise concerns virtually disappear. EE Renewables provides expert air source heat pump installation across Southern England, Greater London, South West England, and South Wales — including areas like London, Brighton, Oxford, Southampton, Bristol, and Cardiff.
Request a free quote and let our MCS-certified team ensure a quiet, efficient, and neighbour-friendly setup.
FAQs
Do Air Source Heat Pumps Get Louder in Winter or During Defrost Mode?
Air source heat pumps can get slightly louder during defrost cycles in winter (temporary fan speed increase), but modern units limit this to short bursts and stay well below regulatory limits.
How Does Background Noise Affect Perceived Air Source Heat Pump Sound?
Background noise (traffic, wind, urban hum) masks ASHP sound effectively — in busy areas like Bristol or London, the low hum often becomes unnoticeable against ambient levels.
Can Acoustic Enclosures or Barriers Be Added to Reduce Air Source Heat Pump Noise?
Acoustic enclosures or solid barriers can be added to reduce air source heat pump noise further, often dropping perceived levels by several dB without affecting efficiency, if designed for airflow.
Are Ground Source Heat Pumps Quieter Than Air Source Heat Pumps?
Ground source heat pumps are generally quieter than air source heat pumps because they lack an external fan unit, producing minimal outdoor noise (around 42dB or less).
What Happens If an Air Source Heat Pump Exceeds the 42dB Neighbour Limit?
If an air source heat pump exceeds the 42dB neighbour limit, it may require full planning permission and potential mitigation measures, though MCS-certified installations rarely reach this threshold.
