Light tower noise: what the night hears and where it starts
A balloon light makes no sound. On a generator tower the sound comes from the foot of the mast, and at two in the morning that is the part of the site the neighbours hear.
Where the noise is made
The lamp and its driver are silent, which is the point of a diffused head: there is no point source to look into and nothing in the head that moves. On a generator tower the noise comes from three parts that are not the light at all, which are the engine, the cooling fan and the alternator. On a battery tower those three are replaced by an inverter with no moving part.
That is why moving the light does not fix a noise complaint. The mast can stay where the work is, while the part that makes the sound is somewhere else entirely, and the two are connected by a cable rather than by a frame.
What carries at night
Sound travels further at night because the air is still and cooler and because there is less other noise to mask it. Hard ground, a wall and a row of houses all shape where it lands. A gravel yard reflects, a hedge absorbs a little, and a mesh fence does almost nothing.
No figure is published here, because the number that matters is measured where somebody is trying to sleep rather than at the machine. Ask the supplier for the sound level at a stated distance in the open, then walk the site after dark and listen at the nearest bedroom window. A level without a distance beside it is not comparable with anything.
The direction of the wind matters as much as the distance. A set that is twenty metres away and downwind is heard as a set that is forty metres away and upwind, and the wind turns during a long shift, which is why the fallback position belongs on the plan as well as the first choice.
The two towers on the same site
The range offers both. A battery powered tower carries a 1000 Wh or 2000 Wh station rated 300 W or 1000 W continuous, and it is silent at the lamp with no exhaust at all. A generator powered tower carries a 2.2 kW set with a 4.2 L tank and a 230 V output rated at 9.6 A, which refuels in minutes and runs any lamp in the range.
The battery tower is not the universal answer. It needs a charging window between shifts, and the largest lamps outrun a station in a few hours. The generator is not the wrong answer either. It is the answer that has to be sited, and siting is cheaper than silence.
Site the engine, not the light
- Keep the mast at the work face and move the power source back along the cable run.
- Put something solid between the engine and the nearest house: a site wall, a container, an earth bund. A fence is not a barrier.
- Keep it downwind, so exhaust does not drift across the work face either.
- Stand it on firm ground, because a set on loose gravel adds rattle to the engine note.
- Put it in the barrier's shadow rather than at the end of it, which is where a barrier stops working.
The hours and the swap
Most complaints are about the last two hours rather than the first six. The quiet window is usually late, and a station can cover it if the plan says which lamps move to the station and at what time. For an event the schedule does the same job: the speeches run on the station, the generator stays off until the stage needs it, and the site is quiet when the guests leave.
Both plans belong on the drawing that goes to the client, next to the lighting layout. A lighting plan that shows where the light lands and says nothing about where the sound comes from is half a plan, and the missing half is the one that generates the phone call.
What goes in the brief
| Line in the brief | What it settles | When it is agreed |
|---|---|---|
| Quiet hours | The window the engine is off | Before the first night |
| Generator position | Where the sound is made | Marked on the site plan, behind a barrier |
| Barrier | What stands between engine and receiver | Named, not assumed |
| Swap time | When the load moves to the station | Written into the shift plan |
| Sound level | The figure the supplier states | At a stated distance, in the open |
The first two lines are the ones a client can check, and they are the two that stop an argument at eleven at night. The last one is the only line that turns a complaint into a specification.
The light is what the site asked for. The noise is what the site is remembered for, and it is decided by where the engine stands rather than by how bright the lamp is.
Updated 2026-10-29 ยท 4 min read. Specifications change without notice; confirm the current sheet before you publish a claim or write a tender document.
Questions that come back
Short answers, before the email.
Is a battery light tower silent?
At the lamp, yes: there is no engine, no exhaust and no fan on the mast. The station has an inverter, which is quiet rather than silent, especially under a heavy load.
How loud is a generator light tower?
The figure belongs to the set and to the distance, so it should come from the supplier as a sound level at a stated distance in the open. A number without the distance is not comparable with another number.
Can a barrier fix a noise complaint?
It helps when the engine is in the barrier's shadow and the barrier is solid and close to the source. A fence or a thin hedge does very little at the low frequencies an engine produces.
Where should the generator go?
Away from the work face and away from the nearest house, behind something solid, on firm ground, and downwind of both.
Can one tower cover a whole night quietly?
Only if the station and the lamp are matched and the shift is short enough. For the largest lamps, plan the swap rather than promise the silence.
Send the site, get the configuration.
Head, mount, power and the specification sheet for each line item, in one reply.