The problem is... doors really don't seal all that well, regardless of how well you try to seal them, so you are sucking a lot of your air from outside the cabinet. If you put the exhaust fan as high up as you can on the back wall, it will work better.

Lower your inside fan so that you are blowing up towards the lights. Right now you are blowing the light heat down on the plants. Up is mucho mejor.

Nice looking box. Very good work! :thumbsup:

PC :smokin: