How Noisy Is An Air Source Heat Pump?

Last Updated on June 27, 2025

Thinking of upgrading to a more efficient heating system but wondering: how noisy is an air source heat pump? If you’re a UK homeowner or landlord considering an eco-friendly alternative to a gas boiler, noise levels can be a major concern. 

After all, your heating system shouldn’t interrupt your sleep or disturb your neighbours.

In this guide, we break down exactly how much noise an air source heat pump makes, what affects the sound levels, and how modern models have evolved to be whisper-quiet. 

We’ll also show you what to look out for when choosing a low-noise unit and why you shouldn’t let sound levels put you off this smart investment in your home or rental property.

How Loud Is an Air Source Heat Pump in Decibels?

Air source heat pumps typically produce 40 to 60 decibels (dB) of sound during operation, similar to a quiet conversation or the hum of a fridge.

For context, a standard gas boiler may produce similar levels indoors, but without the external unit. 
However, unlike boilers, ASHPs run continuously at low intensity, which may raise questions about long-term noise exposure. Luckily, with proper placement and modern design, it rarely becomes an issue.

If you’re still comparing systems, understanding how heat pumps vs gas boilers stack up on other factors like cost and efficiency might also help you decide.

Will an Air Source Heat Pump Disturb My Neighbours?

In most cases, no. If installed correctly, an air source heat pump will not disturb your neighbours.

UK regulations under Permitted Development Rights state that air source heat pumps must not exceed 42 dB(A) at the property boundary, and most MCS-certified units are specifically designed to meet this requirement.

Noise reduction strategies include:

• Placing the unit away from shared boundaries
  
• Installing acoustic fencing
  
• Mounting the unit on anti-vibration pads

Pro tip: Positioning the unit in a shaded, sheltered area not only reduces noise but also boosts efficiency. To better understand this aspect, you might want to read about air source heat pump efficiency and how placement can influence performance.

How Far Should an Air Source Heat Pump Be from Your Neighbour’s Property?

To comply with UK Permitted Development Rights, your air source heat pump should typically be installed at least 1 metre from your property boundary. 

This helps ensure the sound pressure level does not exceed 42 dB(A) when measured 1 metre from the boundary, a key requirement for avoiding the need for planning permission.

However, placement also affects real-world noise impact:

• Minimum recommended distance: 1 metre (legal minimum)
  
• Ideal distance: 2–3 metres or more if space allows
  
• Avoid placing the unit directly opposite bedroom windows or quiet outdoor areas (yours or your neighbour’s)

An MCS-certified installer will carry out an acoustic assessment to make sure your system meets these criteria.

By maintaining the correct distance and orientation, you can stay compliant and neighbour-friendly, without compromising on performance. If you’re unsure whether your layout is suitable, our article on determining if your house is suitable for a heat pump should help you get a better understanding.

What Factors Affect How Noisy an Air Source Heat Pump Is?

Several key factors influence the sound output of an air source heat pump:

• Brand and Model – Premium brands like Mitsubishi Ecodan or Vaillant aroTHERM produce ultra-quiet systems below 40 dB. If you’re looking at options, check out our guide on the best heat pump brands to see which models are rated highly for low-noise operation.
  
• Compressor Type – Inverter-driven compressors operate at variable speeds, making them quieter than traditional on/off models.
  
• Installation Quality – Poorly installed units can rattle or vibrate, increasing noise.
  
• Age and Maintenance – Older, unmaintained systems tend to get louder over time.
  
• Surrounding Environment – Echo-prone walls or hard surfaces can amplify the perceived volume.

Regular servicing ensures your ASHP continues running smoothly and quietly.

Are Air Source Heat Pumps Quieter at Night?

Modern air source heat pumps often include a “night mode” or “quiet mode” that reduces fan and compressor speed after dark.

This feature:

• Keeps noise below 35 dB, ideal for urban or suburban settings
  
• Helps meet local authority planning rules
  
• Reduces electricity usage during off-peak hours

For landlords, this is especially helpful in HMOs or flats, where tenant comfort and compliance are top priorities. If you’re cost-conscious, it’s also worth understanding the cost of running a heat pump to see how nighttime operation fits into your broader energy-saving strategy.

How Can I Choose the Quietest Air Source Heat Pump?

If you’re noise-sensitive or live in a densely populated area, here’s what to prioritise:

• Low dB Rating – Look for models rated under 40 dB(A) in standard operation.
  
• MCS-Certified Installers – They’ll ensure compliance with local planning laws.
  
• Sound Power vs Sound Pressure – Sound power (dB) measures the actual noise output of the unit, while sound pressure (dB(A)) is how loud it sounds at a certain distance. Both are important for understanding the impact on your home and neighbours.
  
• Noise-reduction Accessories – Consider purpose-built sound enclosures, acoustic fencing, or even planting dense shrubs to absorb and deflect noise without affecting airflow.

The Mitsubishi Ecodan Ultra Quiet and the Samsung EHS Monobloc are two of the quietest options available in the UK market.

Can You Soundproof an Air Source Heat Pump?

Yes, you can take additional steps to minimise operational noise, especially in noise-sensitive zones. Some effective solutions include:

• Acoustic fencing or barriers made from timber or metal composite
  
• Anti-vibration mounts for wall or floor installation
  
• Rubber pads or isolation mats – These absorb vibrations between the unit and the ground or wall, helping to reduce humming or rattling noises.
  
• Custom-built enclosures (be sure they don’t restrict airflow) – A well-ventilated enclosure can dampen noise without compromising efficiency, but it must allow for proper airflow to avoid overheating or performance issues.

Always consult your installer first, as airflow restriction can reduce the unit’s efficiency. And if you’re still on the fence about whether the investment is worth it, read our article on whether heat pumps worth it for a full breakdown of their long-term value and return.

Get Your Free Air Source Heat Pump Quote from Eco Happy Today

If you’re considering a low-carbon heating solution and have been holding off due to concerns about noise, let Eco Happy help you find the quietest, most efficient air source heat pump for your home or rental property.

With expert installation, sound-conscious placement, and access to government heat pump grants, we’ll ensure your system performs silently and efficiently.

Ready to future-proof your heating without the noise?

Request your free heat pump quote now from Eco Happy – your trusted renewable heating specialist.