Heat pump noise: decibel limits, distance to neighbours and practical solutions

Heat pump noise: decibel limits, distance to neighbours and practical solutions

After cost, noise is the second most frequent concern about heat pumps. Most modern air-to-water units produce 35-45 dB(A) at 1 metre — comparable to a quiet fridge — but placement, brand and age of the unit determine whether your neighbours notice it or not.

What is the legal noise limit in the Netherlands?

Since 1 April 2021, the Dutch Building Decree (Bouwbesluit) sets a hard limit: the outdoor unit of a heat pump may produce a maximum of 40 dB(A) at night (23:00–07:00) at the neighbour's property line. Daytime the limit is 45 dB(A). The norm is based on average sound level, not peak.

This applies to all newly installed systems. Was your heat pump installed before 1 April 2021? You are not obliged to retrofit unless complaints lead the municipality to issue an administrative order under the Activities Decree.

How many dB does a modern heat pump actually make?

Manufacturers publish two values: sound power (LWA, in dB) and sound pressure (LPA, in dB(A) at a given distance). These are not interchangeable — sound pressure at the property line is what the Building Decree measures.

Brand / type	LWA (dB)	LPA at 1 m (dB(A))	Mode
Daikin Altherma 3 M	54	39	Night mode
Mitsubishi Ecodan PUZ-WM	58	42	Standard
Vaillant aroTHERM plus	54	37	Super Silent
Nibe F2120	56	41	Standard
LG Therma V R290	56	40	Night mode

For reference: 40 dB is roughly the sound of soft rain; 50 dB is a normal conversation at 1 metre.

Distance to the property line: how much space do you need?

Every doubling of distance yields approximately 6 dB reduction. A unit measuring 45 dB(A) at 1 metre produces 39 dB(A) at 2 metres and 33 dB(A) at 4 metres. For modern quiet models, 2-3 metres to the property line is usually sufficient; for older or more powerful units, 5-6 metres may be needed.

The government's online calculation tool estimates noise at the property line based on manufacturer specs and placement distance. Always ask your installer for a noise report before installation — in case of a complaint you must be able to produce one.

Practical solutions for noise complaints

1. Activate night mode. Virtually all modern heat pumps have a quieter mode that engages automatically at night, yielding 3-6 dB reduction — often enough to stay within the norm.
2. Acoustic enclosure. An acoustic hood or noise screen around the outdoor unit can reduce 6-12 dB. Cost: €400-€900. Warning: a poorly designed enclosure restricts ventilation and reduces efficiency.
3. Vibration dampers. Rubber feet under the unit prevent vibration from propagating through the wall or roof. Cost: €30-€80, DIY or by installer.
4. Relocation. Most effective (and most expensive): move the unit to a spot further from the property line or behind an existing wall. Reinstallation: €500-€1500.
5. Replace the unit. If your heat pump is over 10 years old, a modern replacement can be 8-12 dB quieter. Only cost-effective if the compressor is due for replacement anyway.

What if the neighbours complain?

The municipality is the competent authority for noise complaints. File the complaint in writing first with the owner or occupier, proposing a date for a noise measurement. If no agreement is reached, the municipality can measure and issue an administrative order. In practice this gives a 4-8 week deadline to demonstrate the installation operates within the norm.

If the complaint is unfounded — the installation demonstrably meets 40 dB(A) at the property line — you need not adjust anything. An independent acoustic consultant's report (€300-€600) is strong evidence.

Quiet heat pumps: what to look for

If you're still in the selection phase, check these specifications:

• LPA at 1 m in night mode (not just sound power LWA).
• Inverter-driven compressor. A modulating compressor runs more often at low speed and averages less noise than on/off units.
• R290 refrigerant. Propane models (R290) typically have smaller compressors and run quieter than older R410A units.
• "Quiet Mark" certification. Some brands (Daikin, Vaillant) offer a certified ultra-quiet line under 35 dB(A).

Frequently asked questions

How many dB can a heat pump make at the neighbour's?

Maximum 40 dB(A) at night and 45 dB(A) during the day at the property line, measured under Dutch Building Decree rules. Within 2-3 metres of a modern outdoor unit this is achievable; on tight lots it's sometimes tricky.

Which heat pump is the quietest?

Inverter-driven models with R290 refrigerant and a dedicated night mode are generally quietest. Vaillant aroTHERM plus (37 dB at 1 m), Daikin Altherma 3 M (39 dB) and LG Therma V R290 (40 dB) lead the Dutch market.

Do I need a noise report before installation?

Not legally required, but strongly advised. Your installer can make a calculation based on manufacturer specs and distance. Cost: often free as part of the quote. It's invaluable if a complaint arises later.

Can I turn my heat pump off at night?

You can, but it's inadvisable — a modulating heat pump runs most efficiently at continuous low power. A night mode with reduced compressor speed is almost always better than full shutdown.

Does the 40 dB limit also apply to air conditioning?

Yes. Since 2021 the same norm applies to all outdoor units of heat pumps and split-air conditioners. Older AC installations fall under the Activities Decree, where the municipality can intervene on complaint.