Quote Originally Posted by ledtime
Well with the 4" fan the temps got up to 86 degrees. Keep in mind that this is a MH conversion bulb. They get hot! My last readings were from a 400W HPS. I've read that MH bulbs get hotter than HPS bulbs.

I just went out and purchased an ActiveAir 465cfm fan. I took off the carbon filter completely and the temps are staying at 82 degrees. 265cfm more and a 4 degree drop. I was hoping for more.

Is there anything I am missing here? Ambient room temp is 75 deg. With a big ass fan like this is the 7 degree increase reasonable?

These fans aren't easy to mount. There are no hanging tabs at all.
Hey ledtime,

Describe the space.
Have you taken temp readings at various locations in the tent? Like ditdotter suggests, make sure you are stirring the air sufficiently. I ended up with 3 internal fans before I was happy with the circulation. A 7F rise isn't horrible, considering the restrictions, but you can do better.

On the store-bought tents, if you have the headroom, you can cut a piece of plywood to rest on the top supports outside the tent. That's an easy way for mounting those A-A fans. Are you still having to use the (2) reducers? Those squirrel-cage fans hate any restrictions.

What size flange is on the active-air?

Aw, what the heck, use 'em both. Get a 6" flange for the A-A and dedicate it to the carbon filter. Vent the cool-tube with the Wind-Tunnel and it'll be downright chilly.
EvilCartman Reviewed by EvilCartman on . 400W HPS w/4" Sunleaves Windtunnel Fan Just a heads up to everyone. I've looked all over this forum and had to piece together info from several posts. My setup is the following: Carbon Scrubber (18" long x 6" Diameter - Closed cap on one end and 6" to 4" reducer on the the other) That is directly connected to the inlet of the 4" Sunleaves Windtunnel fan. I then have a 4" elbow to a 4" to 6" increaser. Then 6" aluminum flexible ducting to the bulb end of the cooltube. After that it's just 6" flexible ducting out of the Rating: 5