Fans Or Vents On Roof

[pastafreak]

Do these run at all times, or does it vary through out the day?
I am on the upper floor, and hear a humming noise late evenings, but not all the time or on any schedule.

[jennyjoan]

A friend of mine had a neighbour in a fold/flats/apartment, who kept hearing humming all the time. She brought friends in to "listen" but they couldn't hear anything. She brought the owner of the property - they couldn't hear anything.

However after all that - it was the gentleman below her on an oxygen machine hence the hum.

[jennyjoan]

or somehow it could be a generator on and off.

[pastafreak]

Ah...but how come others couldn't hear it? Wouldn't it be on all the time?
There is no one here on oxygen to the best of my knowledge.

[jennyjoan]

yes oxygen would be on all the time as I have a friend who is on oxygen 24/7. The big machine is run by electric (like a radiator) and hums noisily enough - then she puts on the back pack for bed time, I'm not sure - would that be a battery.

[ummmm]

I had extractor fans in my bathrooms which came on when I turned the light on.

[barry1010]

Could be bathroom extractor fan, probably the most likely.

[Zacs-Master]

Could be anything. A kitchen fan. A bathroom fan. Air Con unit. General ventilation to a property. Boiler in neighbouring property.......