Agree with their, well ya except in my cutting/seedling wardrobe which dosen`t have extraction, but it was bought for the flowering cupboard and did squat diddly do or fuck all in Ingleesh.
On your extraction @Benjic93 if your drawing air in from same room tent is in, then maybe extract into that room but cus heat rises and it will escape out of gaps in sheds around roof edges and such like where you say gaps are, maybe set your extraction ducting from a lower hole on tent around ground level on piss at an angle so warm air bounces around or off outhouse walls, as it rises kinda thing.
if its possible set inlet duct near that warm air, what with heat rising and all that shit. I`m not saying it will solve problem but surly it will help a wee bit more and every little helps or so i here. Only problem i can see and tbh i doubt it will be one, will be recirculating the possibly humid air at times, but give it a try and keep eye on humidity and temps see what goes once set.