well av just thought ov a ventilation problem i.e extractor fans,,,,am goin 2 put a 4in hole in my roof in each section, insert a 4in soil pipe thru roof then am goin 2 fix a car radiator fan under each soil pipe and run them off me 2 caravan batteries that are wired up 2 my solar panels ,,,,,oh the joy!!!!!!!!!!!!!!!!! ;D ;D ;D ;D ;D