yes but he has 5 vent holes and 2 fans so it shouldnt be a problem.. as long as the heat has somewhere to escape to and as long as the air is flowing the heat that the CFL's put out will be almost non existing. pfc an exaust is always the best thing to have... i know people who grew plants with a closet some cfls and a tablefan and got decent results. try to get a stable 20-26c temp and you will be fine. make sure to have your CFLs as close to the plant as you can. you have a preatty small space so 1-2 plants should do it. just make sure not to veg for to long and train the plant in veg (topping, LST, supercrop or whatever you think is best for your area..).