Are exhaust fans suppose to suck tents in???

Hello all, I have a 52" x 24" x 48" tall tent, and have a 240 cfm inline exhaust fan, with an 80 cfm intake..Cranked it up for a test run, and I thought the tent was gonna collapse, and suck all the stitches out..I thought my wife wore tight pants, but no where NEAR as tight as this tent got LMAO.. Is this normal?? I opened the vented flap in the back which helped some, but when I start flowering, I want it light proof... I know the norm is 25% intake, 75% exhaust....any advice anyone???

Steverino

You are creating negative pressure inside the tent. You will always need some sort of passive or active intake into the tent when the exhaust fan is running.

If it is a problem then you can get fan speed controllers to lower the revolutions on your fan.

But yes, you want at least a slightly negative pressure on the tent so no smells escape.

And the norm is 2* passive intake to active exhaust. 75% exhaust is wrong.

I agree with NLX, you are creating negative energy inside which needs to be regulated. Are you using a carbon filter, or just sucking the air straight out? I am using a 165 CFM inline fan which is cooling my reflector/bulb, and filtering the air through a 4" carbon filter. I am growing in a 5'x5'x6' tent which has three intake vents which controls the negative energy inside. I think a 240 CFM may be to much for your tent, and for your ladies britches. I have my timer set to come on for 15 minutes on, 30 minutes off, 30 minutes on, 30 minutes off for the lights on cycle which keeps the ladies environment ideal. I couldn't imagine putting anything larger than a 165 in my tent, hope this helps.

Gotcha fellows!! Thanks! I can regulate the fan, it is a bilge 4" inline fan, and its 12 v. 4.3 amp..Car battery equivalent. I had to get a regulated power supply. Noticed that it has an adjustment for controlling voltage. I turned it down, and it is doing much better. very slight pulling in on the tent. I'd say 5-10% more out than coming in..Seems that will work alot better!