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 tent.

My ambient room temp is 75 deg. My tent temp.....75 deg. Have the cooltube 12" off the plants and there is absolutely no heat.

600W will be here on Tuesday. Will let you know how the temps are then. I'm hoping not much difference.

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.

How much air circulation do you have in the grow tent itself? If you don't have any I would suggest this as your next course of action. The addition of fans dropped my grow room temps about 3 to 4 degrees above ambient room temps during lights on and about the same lower during lights off. Which means about 75-76 degrees for highs and 68-69 for lows.

You really need to get the air moving around inside the tent. Your plants will love you for it.

I have a big fan blowing around in there.....Steady at 84 deg.

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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.

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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. :D 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. :)

I took the 4" flange off of the input of the AA Fan so that it's running wide open. It then has the 4" out flange put on there with a 4 to 6 increaser. 6" ducting to the bulb end of the cool tube (6" Dia.). 6" Ducting from the other end of the tube out of the tent vented out of the room.

It's a DR100 39.5" x39.5"x72". Have a tower fan at full blast moving 90 degrees back and forth from the corner covering the entire area.

Quote:

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Originally Posted by ledtime

It's a DR100 39.5" x39.5"x72". Have a tower fan at full blast moving 90 degrees back and forth from the corner covering the entire area.

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Are you using the screened intakes? A short length of duct, to draw directly @ floor level may help some. It's easy to make a flange with some cardboard and Velcro tape, to attach at the screened opening of a DR. (I've got an 80 & 120) If you've got a window nearby, it would allow you to draw from there. (assuming it's cooler out there,..wherever you are) :D

I am just going to go back to the 400W. I think the 600W is just way to much for a DR100. It's just over 3' sq on the footprint. I think i would have to run a really huge fan to move the heat out of that small space quick enough. Not something I want to get into. With the 400W there was maybe at worst 1 to 2 deg increase in tent temp over ambient room temp. That is what I want.

Took the Active Air fan back to the hydro store today and they gave me a full refund. My 4" windtunnel does great sucking through the carbon scrubber, blowing through the cooltube and out of the room. If it ain't broke don't fix it right?