I am almost ready for my first grow. I got my light yesterday an installed in my closet.(42x21x71) my basement temp is about 62 degrees. I have a thermometer that can give me the temp at two locations in my closet. with my light on for about twenty minutes(holly cow is that thing bright!) and the light lowered to about two feet(which is about where I think it will start) the upper tem was 82 and the lower tem was 109!! My first thought is I need a bigger exhaust fan, I thought the one I have was 100cfm, turns out it is only 50cfm. My exhaust is in the upper right, and my intake is in the lower left. Should my intake have a fan in it, or is just an open vent ok. I also put mylar on the floor, If I remove this will this help. My light is a 400w HPS/MH and unfortunately is not able to have the venting run throught it. I also did this test with only the exhaust fan running an no interior fan. I would appreciate any suggestions.