Temperature/ventilation problems

[medichron]

Hey everyone, I'm midway through flowering in my first medical grow and I am having some heat issues. My tent is 3x4x7.5 and I have an air cooled 400w hps and 6" hydrofarm ducting. I didn't have enough cash to buy another fan for exhaust so I am running the air cooled hood open on one side so it's pulling air from the room through the light and out the tent. I also have a desk fan that I hooked up to a 6" duct which is pulling air into the room. Temps are around 82-84 with the light on and the door shut. I can bring down the temps a few by setting up a small fan blowing air out the door of my tent, but I dont like to do this because my grow is in my bedroom and the lights are on while I'm asleep (it's bright as hell if the tent door is open). The temps are 65-70 with the lights off. Is this too much of a temp change between light and dark cycles? How can I bring my temps down more without spending a bunch of money on another can/squirrel cage fan?

If you want to see more about my grow click on my profile and check out the thread labeled first small medical grow...

Thanks for any suggestions

Peace
Medichron

 

[Mr. Hugeblunts]

What are the ambient temps lights on? outside the cab.

I run a 400w in 3x2x4 batwing ballast and a 150cfm dayton blower with only 10*F above ambient.

What kind of fan do you have for your exhaust? These temps aren't normal

 

[medichron]

I'm running a 4" squirrel cage fan directly mounted to the air cooled hood. I think is around 240cfm. Ouside the cab temps are always 65-70.

 

[morrisgreenberg]

in similar conditions i had an air cooled 400 hps open ended like yours blowing into the hood and got it to 80F, i think thats that best your gonna get and wouldnt stress it unless your running hydro and water temps climb, night temps are fine. mind you i used a $25 home depot duct booster fan, if your not using this fan to suck heat then your at your limit

 

[Jnugg]

Dump the squirrel cage/blower fan and get yourself a nice 6" inline centrifugal (Vortex,Can Fan,Eco Plus,Elicent) or a 6" S&P Mixed Vent.