Wait, so your shed isn't actively ventilated? That's why it's 90 in there. You need to have at least a passive intake area for air to come in and an inline fan pulling through a filter and blowing the air out of your shed through some kind of an outlet. Not only do you need to do that to cool it in there but you need fresh air coming in for the plants to breathe. The carbon filter on the extraction fan will keep everything from smelling so the neighbors don't get nosey.