Help with cooling

Hey whats up guys. I'm having a little problem cooling my tent and dont know if there is a solution or not. I have grown decent bud in it but i think if temps were down it could be better. I'm running a 600w hps cool tube with fan pulling through carbon filter then through cooltube. The 2'x4'x5' tent is in a 5' x 16' room that has no windows or ducting so the fan is just recirculating hot air once it pulls it into the tent. I do open the door once in awhile but its only a temporary fix. any ideas would be awesome. thanks