Hi everyone been doing alot of reading but ive still run into some problems. Ive constructed my first grow box that measures 2x4x5. I have my sun system V in there which is 250 HPS bulb + ballast. For my exhaust i have a dayton blower rated at 465 CFM, with passive intake grilles at the bottom of the box. When i run the HPS and fan temps still blow past 100F.

from what i read for proper ventilation you need the fans to replace 3-4x more than the total cubic space in less than 5 minutes. My total cubic feet = 40 cubic feet. So ideally i would want a fan rated at about 120-160. I thought the 465 CFM blower I had would suffice.

can anyone tell me something im not doing right or what im doing wrong?
Cicatriz Reviewed by Cicatriz on . Heat Problems with 250 HpS Hi everyone been doing alot of reading but ive still run into some problems. Ive constructed my first grow box that measures 2x4x5. I have my sun system V in there which is 250 HPS bulb + ballast. For my exhaust i have a dayton blower rated at 465 CFM, with passive intake grilles at the bottom of the box. When i run the HPS and fan temps still blow past 100F. from what i read for proper ventilation you need the fans to replace 3-4x more than the total cubic space in less than 5 minutes. My Rating: 5