Near homes, what bothers people most is noise at night, repeated starts and short bursts such as the hiss of drains. An enclosed screw compressor (65 to 72 ± 2 dB(A) according to the data sheets of our range), placed in a closed room whose openings do not face the houses, and a leak-free network that lets it stay off at night, greatly reduce the nuisance.
Rules on neighbourhood noise vary by location and activity: check with your local authorities. For choosing the machine itself, see our page on the quiet workshop compressor.
What really bothers the neighbours
- Changing noise. A compressor that starts, stops and restarts catches the ear more than a steady sound.
- Short bursts: the hiss of a condensate drain, unloading at stop, a safety valve.
- Nights and weekends, when background noise falls and the compressor restarts to make up for leaks.
- Vibration carried through a party wall or a shared slab.
- Ventilation openings, through which noise leaves the room.
Step 1, a quiet machine
A screw compressor compresses air by continuous rotation, inside a soundproofed enclosure. A piston compressor produces a hammering that carries further: near homes, avoid it for regular use.
Values from our data sheets: S 75 65 to 68 ± 2 dB(A), K 75 66 ± 2 dB(A), S 110 68 to 72 ± 2 dB(A). A correctly sized compressor is also quieter than an oversized one. Variable speed helps: when the site uses little air, the motor turns slowly instead of switching between running, stopping and restarting. Our article on variable speed explains how.
Step 2, the right location
- On the side away from the houses. Put the compressor room or area on the side facing the street, the yard or a non-residential building.
- Air openings facing the right way. The fresh air inlet and hot air outlet must not face the neighbours' windows. If you add acoustic louvres or silencers, they must still pass the airflow required by the manual.
- Not against a party wall. Stand the machine level on a stable floor, and connect it with a flexible hose.
- Doors shut. A closed, ventilated room blocks much of the noise: see where to install your compressor.
Step 3, keep it off at night
Our screw compressors stop by themselves once the set pressure is reached, and restart when it falls below the threshold. With no demand, they stay off. Leaks are what wake them up.
Step-by-step calculation, as an indication, for 100 L/min of leaks over a 12-hour night:
- Air lost: 100 × 60 × 12 = 72,000 litres, or 72 m³.
- Running time of an S 75 at 1.1 m³/min: 72 ÷ 1.1 = about 65 minutes.
- Those 65 minutes are spread over repeated starts throughout the night.
Three steps:
- Fix the leaks: see detecting and repairing leaks, and put a figure on the loss with our leak cost calculator.
- Close an isolating valve at the end of the day, if no machine needs air overnight.
- Pipe the drains. Connect the outlet of the automatic condensate drain to a line running to an oil/water separator, instead of letting it blow into the open air.
Step 4, measure before and after
A sound level meter, even a simple one, gives you an objective baseline. Measure at the property boundary, by day and by night, with the compressor running and then stopped. Measure again after each change: you will know what really made a difference.
What if air is needed at night?
Shift work means the compressor cannot be switched off. The closed room, the direction of the openings and a correctly sized variable speed machine then matter all the more. Our compressed air audit measures actual night-time consumption and leaks before you choose.
Describe your site and where the houses are in a quote request: we will help you choose the machine and its location.
For your trade: Quiet compressor for workshops.