Issues with High Temps in Grow Tent

I have a 400 watt hps in a 28 x 36 x54 cab, vented by a 4 inch 190 cfm fan that runs at about 80% during lights on, with passive intake.When the doors shut it gets to 82, with the door open its 78-79, drawing in the 72-74 degree air in my house. if my 4 inch fan can keep that small a space under 82, something aint right with your setup.
i guess the big difference is that i'm using a hood with the glass in it. i'm lucky enough that i don't need to use a filter, my fan vents onto a hillside behind my house with no neighboors.
use the glass.
if you want the UV, get a tanning lamp, or reptile lamp. usually 10% of your output in uv is enough to effect potency, so you'd only need 30 watts or so of UVB. they do run warm, but not nearly warm enough to equal having the glass out of your hood.

Not to mention the UV will do to your eyes, in such a tight place,...avoid or play catch up later?

in most instances the inlet is left passive

to suck air from the surrounding area, removing smells, trashing heat

consider hooking both fans to extract

good luck

On my tent I run a closed hood venting the heat from the bulb out of the tent. This allows me to keep my heat in check.

Just wanted to thank everyone for their help! I took everyone's advice, adjusted my fans appropriately, got a small clip-on fan for the inside of the tent, and got a nice portable A/C on sale at Lowe's. Now I feel like I am a god of my own little ecosphere. I can control the temp to my liking while keeping my CMH bulb naked in the reflector at whatever distance I wish from the canopy.

T.C. Bosby said:

Just wanted to thank everyone for their help! I took everyone's advice, adjusted my fans appropriately, got a small clip-on fan for the inside of the tent, and got a nice portable A/C on sale at Lowe's. Now I feel like I am a god of my own little ecosphere. I can control the temp to my liking while keeping my CMH bulb naked in the reflector at whatever distance I wish from the canopy.

Click to expand...

Which unit from Lowe's? I will be getting a new tent and CMH soon and might need to go the same route?

Thanks and congrats

They have a 10,000 BTU portable A/C for $279. It is made by Hisense. I just have my intake duct at the bottom of my tent using an inline fan. It has the following functions: Cool, Dry, and Fan. When the AC is going the air is sucked in by the intake duct (it has a Dust Shroom on it to help filter out anything brought in from the outside). Using a bare bulb in my reflector, I've had it 12 inches away from the canopy and reduced temps to below 70 degrees. It can easily keep temps at 75 and lower.

One thing for sure though is be sure to have a small clip-on fan inside the tent. I have mine pointed towards the light just to keep the air moving beneath it.

In a nutshell, my exhaust system is (BTW. my tent is 3'x3'x6'11"):
At The Bottom of the Tent: Intake with filter sitting on top of A/C unit's vent. Speed controlled Active Air 6 Inch inline fan pushes the air into the tent.
At The Top of the Tent: Speed controlled Active Air 6 Inch inline fan exhausts air outside of the tent.

I have the exhaust fan running a little faster than the intake fan. This creates just a little bit of negative pressure which helps force the heat out of the tent. Even though it isn't the best choice, I vent the exhaust into the same room that my tent is in (My wife doesn't want ductwork running around our bedroom). But the A/C does such a good job of cooling that it makes my bedroom an icebox. At night I'm using a down comforter to stay warm.

Thanks for the heads up.

Looks good and if it works good even better lol.......

A $20 PID controller with an RTD thermometer ($9) can easily be set up with a fan to keep your area at an optimal 80-86F. These are the same units the foodies use to make Sous Vide!
http://www.ebay.com/itm/New-Digital-PID-Temperature-Controller-Control-RNR-1-Alarm-Relay-Output-TC-RTD-/110851344776?hash=item19cf414988:m:mtByIhcdh_MNe4yLNBcBoaQ
http://www.ebay.com/itm/RTD-Pt100-Temperature-Sensor-Thermocouple-2M-Cable-10CM-Probe-3-Wires-50-500-C-/281581039687?hash=item418f89b047:g:aeYAAOSwWKtUyiz~

a really big fan (or heater) will also need a relay,
mounting them in one of these makes a nice compact unit
http://www.homedepot.com/p/Carlon-6-in-x-4-in-Junction-Box-E987RR/100404096

for about $50