What a load of info. And how unusual... It all makes sense.

I can't thank you enough for your help. I see that the image reaper agrees with you and Zandor about the fan pushing air over the light. That's good enough for me. I will make sure that happens.

I hereby vow to do everything whithin my power to:

1) Replace coiled line with real ducting whenever possible.
2) Take out as many bends as possible.
3) Make any bends as gentle as possible.
4) Use 6" line whenever possible.
5) Make the run of ducting as short as possible.

A lot of possiblities, and a lot more work for me ahead. The above, with my new larger fan, jut might do the trick.

I have the same fan you have, using 6" lines (mainly 6" warm air pipe) and only using flexible line for maybe 2 ft on each of THREE 1000 watts lights, and I have total of about 20 feet from start to finish.....no problem.

Good Lord! You are my hero. Is there a picture of this posted somewhere?

Again, thank you.
Opie Yutts Reviewed by Opie Yutts on . Calling SpaceNeedle. HVAC question. I was told to search you out because my question wasn't getting answered in my thread here: http://boards.cannabis.com/indoor-growing/125263-ventalation-fans-fans-fans-fans.html Ultimately my question boils down to this: (from the thread) I guess I just wanted to know where in an 18 foot run of duct that has a light in the middle of the run, would you place a 275 cfm and a 175 cfm fan to get the best cooling possible. Forget all that other stuff, if someone could just answer that it Rating: 5