Will my air conditioning annoy the neighbours?
Realistically? No — not if it's specced and sited properly. Modern domestic AC is dramatically quieter than the units your parents remember from 20 years ago. Here's exactly how loud they are, what the UK rules say, and what we do on every install to keep next-door happy.
Real dB figures for the units we fit
| Unit | Indoor (low) | Outdoor (full) |
|---|---|---|
| LG DualCool 2.5kW | 19 dB(A) | 45 dB(A) |
| Mitsubishi MSZ-AP 2.5kW | 21 dB(A) | 46 dB(A) |
| Daikin Perfera 2.5kW | 19 dB(A) | 46 dB(A) |
| Samsung WindFree 2.5kW | 22 dB(A) | 48 dB(A) |
For context: a quiet library is 40 dB(A), a normal conversation at 1m is 60 dB(A).
The UK 42 dB(A) rule
Under permitted development (Class G), the outdoor unit must not exceed 42 dB(A) at 1m from any neighbouring habitable window. Sounds tight — but noise drops roughly 6 dB every time you double the distance. So a 46 dB(A) unit sited 4m from next door's window is comfortably under the limit.
What we do on every install
- Site the outdoor unit away from adjacent bedroom windows.
- Use anti-vibration rubber pads on the wall bracket (kills structure-borne noise).
- Prefer LG or Daikin — they're the two quietest at the outdoor unit.
- Set "quiet mode" as the default on the remote — cuts night-time output to 38 dB(A).
- Give you a signed sheet with the calculated dB at the fence line, for your records.
How quickly noise fades with distance
Sound drops roughly 6 dB every time the distance doubles. Here's what a typical 46 dB(A) outdoor unit actually measures as you move away from it:
| Distance from unit | Approx. level | Sounds like |
|---|---|---|
| 1 metre | 46 dB(A) | Quiet fridge hum |
| 2 metres | 40 dB(A) | Quiet library |
| 4 metres (typical fence line) | 34 dB(A) | Soft whisper |
| 8 metres (neighbour's window) | 28 dB(A) | Rural night-time background |
A fence panel or wall between the unit and next door knocks off another 3–5 dB on top.
What actually happens if a neighbour complains
A complaint to the council isn't an order — it triggers a process. Environmental health will usually visit, sometimes more than once, and measure the noise inside the complainant's home with windows open. Only if it's judged a "statutory nuisance" (a high legal bar, meaning it materially interferes with their use of their home) would an abatement notice follow.
For a modern inverter unit sited properly, measurements almost never get near that bar. And because we hand you a signed siting sheet with the calculated dB at your fence line, you have paperwork showing the install was done to the permitted-development standard — which resolves most disputes before they go anywhere.
The quietest setups we fit
If noise is your top concern — say a tight terrace in Dudley or a semi in Solihull — these are the combinations we reach for:
- LG DualCool — 45 dB(A) outdoor, 19 dB(A) indoor. Our default for bedrooms; see why we fit LG.
- Daikin Perfera — 46 dB(A) outdoor with a dedicated night-quiet mode that caps it at 38 dB(A).
- Ground-mount behind a fence panel — for very tight plots, sitting the condenser at ground level behind fencing can be quieter than wall-mounting near a boundary.
Cooling a nursery or child's room? Noise matters even more there — read our baby and child bedroom AC safety guide and the bedroom air conditioning page. For a full decibel breakdown of every unit we fit, see the quietest AC units in the UK (2026).