WarmtepompGeluid
Add a receiver position first to see results.

Property

Residential zoning

Outdoor unit

Zb = 0.90 m · Q = 2

Margin

3 dB

Sound power

Buildings

Garden walls

Left
Right

Receiver positions

No receiver positions. Click '+ Receiver position' on the map to add one.

Buitenunit staat op hoogte - controleer ook ramen/deuren van buurwoningen! Voeg ontvangposities toe op de hoogte van nabijgelegen ramen.

Result

Evening+Night
0
dB(A) max LwA
Day
0
dB(A) max LwA
Qbron = 2 · Margin = 3 dB
Max Lp at boundary: 0 dB(A)
(at LwA = 51)
Side cross-section
Side cross-section — Shows the height of buildings and the sight line from the outdoor unit to the loudest point on the property boundary. There is a clear line of sight between the outdoor unit and the measurement point.

Calculate heat pump noise at an apartment

For an apartment the noise assessment works differently than for a house with its own plot. There is usually no plot boundary between the dwellings: your neighbours live on the same plot — next to, above or below you. The sound is therefore not assessed at a boundary but at openable windows and doors of the surrounding dwellings (article 4.108(3) Bbl).

This preset therefore runs in “positions” mode: first place one or more receiver positions on the neighbours’ windows and balconies (“+ Receiver position” button) — without receiver positions there is nothing to assess and the result stays empty.

How to use the tool for this situation

  1. 1
    Draw the building

    The grey block is the apartment building. Adjust its dimensions and height under “Buildings”.

  2. 2
    Place the unit

    Put the unit where you intend to mount it: on the facade, a balcony or the roof. Set the height (Z) to the real mounting height.

  3. 3
    Add receiver positions — required

    Click “+ Receiver position” and tap the map at the neighbours’ windows and balcony doors. Set the correct height (z) per point: the centre of the window. These are the legal assessment points.

  4. 4
    Configure each position

    Per receiver, indicate whether the unit is screened from it, and pick the Q factor: 0.5 for a position in a corner with two walls, such as an enclosed balcony.

Assessment at windows instead of a boundary

Within a single plot the 40 dB limit applies at the openable windows and doors of other dwellings — the upstairs neighbour’s bedroom window, the balcony door next to you. The distance from the unit to those points is often only a few metres, and facades, balcony slabs and parapets reflect the sound. A balcony acts as an acoustic corner: between floor, facade and side wall the same unit is perceived up to 6 dB louder (Q=0.5).

For assessment points in front of a facade without an outdoor space, the method additionally applies a 5 dB facade correction. The tool handles these corrections per receiver position; you only need to set the geometry and per-point settings correctly.

Permission and practice in an owners’ association (VvE)

Besides the Bbl noise requirement, an apartment installation almost always needs permission from the owners’ association (VvE): the facade, balcony railing and roof are common property. Many VvEs ask for acoustic substantiation before agreeing — a calculation from this tool (shareable via the “Share” button) is a good starting point, possibly followed by a formal acoustic report.

Measures that make the difference in apartment settings: a unit with low LwA and a silent night mode, vibration dampers on the bracket or floor, avoiding enclosed balcony corners, and talking to the immediate neighbours before installing.

How does the calculation work?

The calculator is based on WPAC-geluid V2020, the official Dutch calculation tool for noise from outdoor heat pump and air-conditioning units, developed for the Ministry of the Interior. It computes the sound transmission loss (D) from the outdoor unit to each assessment point: the larger the transmission loss, the more sound power the unit is allowed to produce.

Distance is the dominant factor: every doubling of distance reduces the level by 6 dB. The directivity factor Q also matters — a unit within 2.5 metres of one wall (Q=1) is 3 dB louder than a free-standing unit (Q=2), and a corner between two walls (Q=0.5) adds another 3 dB. Reflections from building walls raise the level, while buildings between the unit and the assessment point screen the sound.

The transmission loss yields the maximum allowable sound power (LwA) of the unit: max LwA = limit + D − margin. The safety margin (default 3 dB, minimum 2 dB) covers design and measurement uncertainty. Compare the calculated maximum with the sound power on the unit’s energy label or product documentation.

The noise limits in brief

Since 1 January 2024 the noise requirements for heat pumps and air conditioners are set by the Besluit bouwwerken leefomgeving (Bbl), the successor to the Dutch Building Decree 2012. Article 4.107(2) Bbl states that an outdoor heat or cold generation installation may cause at most 40 dB at the boundary with a neighbouring residential plot. For situations on the same plot — such as apartment buildings — the same limit applies at openable windows and doors of another dwelling (article 4.108(3) Bbl).

The 40 dB limit applies in the evening and at night (19:00–07:00). If the unit has a low-noise setting (silent mode) active during that period, a limit of 45 dB applies during the day (07:00–19:00). Without silent mode the unit must meet 40 dB during the day as well. Read more on the heat pump noise limits page.

Frequently asked questions about this situation

Why do I see no result in this preset?

Apartments are assessed at receiver positions, not at a plot boundary. First add at least one receiver position (“+ Receiver position”) at a window or balcony of a neighbouring dwelling — the results then appear.

May I hang an air-conditioning unit on my balcony?

The Bbl noise rules apply to air conditioners as well (they are the same “heat or cold generation installations”). In addition, VvE permission is almost always required because the facade and balcony are common property. Check the house rules too.

Which Q factor do I pick for a balcony?

If the receiver position sits in a corner with two or more walls (side walls and facade count, the balcony floor does not), pick Q=0.5. One nearby wall: Q=1; free in front of the facade: Q=2. The tool explains this when configuring each position.

Does the limit also apply to my own dwelling?

No, the limit applies at other dwellings — the neighbours. No statutory outdoor levels apply for your own comfort, though it is obviously wise not to mount the unit right next to your own bedroom window either.

Calculate other situations

In the garden On extension On outbuilding On the roof

Further reading

This calculator provides an indicative result based on WPAC-geluid V2020 and does not replace a formal acoustic study. When in doubt, consult an acoustic consultant or your municipality.