Try to read up on using light efficiently by DANGERDAN also, it’s a gold mine of understanding the light footprint you need to gauge the right light for your plants at different stages and according to the size of space you are using is important, build up of that type of heat, over 1600 w in total is accumulating at the top of a wooden shed, I assume it’s wood, best way is to vent thru ducting ducting if possible running through a double ended hood where you can attach ducting and then a fan sucking out the air, depending on size of grow area will determine what size fan you will need, but I will assume at least two 8 inch inline fans, one to suck out the hot air, through the light fitting, which would be your my,hps fixture,the other to suck in fresh preferable from the bottom, ,