A vented dryer running inside a closed cupboard puts every litre of water it pulls out of your clothes into the air of that cupboard. It then condenses on the coldest surface it can find, which is usually the back wall, the underside of the shelf, or the ceiling.
This is the most common thing we’re called to fix in unit laundries, and it is almost never presented as a ventilation problem. People call about mould, or about cupboard doors that have swollen and stopped closing, or about a smell. It’s the same problem every time.
Three ways out of it, in increasing order of cost:
- Duct the existing vented dryer outside properly, if there’s an external wall or an existing vent to work with
- Put in a decent exhaust fan that runs on a timer after the dryer stops, not one that switches off with the light
- Change to a condenser or heat pump dryer, which puts the water in a tank instead of the air
The last one costs the most and solves it most completely, and it’s worth mentioning that a lot of people replace a laundry twice because nobody raised it the first time.
