I always just cooled by small 250HPS tent..which was in cool basement..with 2 4" axial fans. Temp and environment were perfect. Now tent has to go in a detatched garage on wooded side of house. Not in sun blazin. I also want to up to a 400HPS. I doubt the axial fans will b enuf with the 250..nevermind the 400..being the tent is now in detatched garage. I would like to replace the axials with a sufficient silent 6" exhaust..what do u guys recommend? In summer the garage ambient temp about 80. I also run an osculatin fan and a tower fan in tent. Thx