make sure you haven an air intake.....any 'warm' air removed by your fan needs to be replaced by cool air outside your grow area.
SpaceNeedle Reviewed by SpaceNeedle on . grow box heat problem I Made a grow box out of a 22g rubbermaid tub. It have 4 cfl 26w light bulb in it. With a computer fans on the side to get the air out It look great but it get very hot and very quick too. So i dont kno wat to do. Rating: 5