Noise from an AC unit or heat pump? We measure and advise.
The popularity of heat pumps and air conditioners is growing rapidly due to the energy transition. But the outdoor unit produces noise, often a constant low-frequency hum that is especially perceived as disturbing at night. In densely built residential areas this can exceed the limit from the Dutch Building Decree (Besluit bouwwerken leefomgeving, BBL) and lead to sleep disturbance and neighbour conflicts.
Schedule free consultationThe noise standards for heat pumps and AC units
Since 1 April 2021 the outdoor unit of a heat pump or AC unit may produce at most 40 dB at neighbouring homes. This requirement is set in the Dutch Building Decree (Besluit bouwwerken leefomgeving, BBL): article 4.107(2) (measurement at the property boundary for homes on separate plots) and article 4.108(3) (measurement at an openable window or door for apartments). The determination method is set in the Environment Regulation (Omgevingsregeling, article 5.59 and annex XVII). If the installation produces tonal noise, i.e. a hum, the method adds a 5 dB penalty. The old Activiteitenbesluit is no longer the governing framework for this situation.
What do we measure for heat pumps?
Sound level at the relevant assessment point (the property boundary or an openable window) compliant with the BBL. Frequency analysis (1/3 octave bands) to establish tonal noise. Background level (reference without the installation) to isolate the specific noise. For low-frequency problems we extend the analysis down to 20 Hz.
Solutions for exceedances
Sound-insulating enclosures can reduce the noise by 10 to 20 dB if correctly dimensioned (ventilation must remain guaranteed, otherwise the unit overheats). Vibration dampers under the unit prevent structure-borne noise via the wall or roof. Relocating to another façade increases the distance to the affected party. Sound screens are effective at larger distances. We calculate which measure is most effective and cost-efficient in your specific situation.
Legal route for heat pump disturbance
When the standard is exceeded you can ask the municipality to enforce. In a civil law procedure our report is the evidence of unlawful nuisance (article 5:37 Dutch Civil Code). Many legal expenses insurances reimburse the cost of the measurement. The number of legal disputes about heat pump noise has risen sharply in recent years.
Consultation or direct quote
Schedule a free consultation or request a direct quote via the form. We respond within one business day.