yes way to big.......If you went to a 400w you would need actual exhaust system....That means 4"inline fan and a space of minmium of 3'x3'x6' space.... a dresser is not big enough for a 400w and you really need to have fresh air with co2 coming into your "shoe box" grow and old co2 depleated air must be removed..... If your not doing this then it dosent matter wether you use your 250w or 400w it will be No bueno.....