I'm based in Scotland and have a 40 foot by 10 foot tongue and groove shed that is used to store clothes for my business. It sits slightly above ground on a wooden base. I have added a metal roof on top of the existing wooden one. Inside I have put in a false floor and I've also screwed plywood over joists on ceiling.
On the walls all around I’ve firstly left an air gap of 2 inches before fitting in foam insulation sheets then stapled VC moisture barrier silver backed foil to joists before screwing plywood onto the joists and lastly used sealant to seal every little gap.
The problem is that in winter it is freezing and summer stifling hot
And after a few years now I’m starting to smell a stale dampness and worried that it will transmit to my clothes stock.
So my question is should I heat or dehumidify put in air vents or all
Best Answer
You have to decide whether the relative humidity of your environment is adequately dry for your storage needs. If not, you have to reduce moisture. We can't really say what's right for you.
It sounds like you have the space sealed up fairly well. For that reason I'd consider just using some bulk desiccant. It won't cost electricity and you won't have to worry about emptying buckets or pluming a drain line. If the building isn't very well sealed or you open doors frequently this could get expensive.
The best bet might be a window air conditioner. This would cool and dry the interior while keeping the generated heat outside.
Otherwise you could run a dehumidifier, but that creates heat and you'll probably want to plumb the drain line out somewhere. You wouldn't want to dehumidify and ventilate because you'd never catch up. This means the heat stays inside until it is conducted out through the building envelope.
I don't see ventilation being a great option. By reducing the interior temperature you may actually increase the relative humidity, and you introduce more mold spores than you'd have otherwise.