I have the valuline 6' and a Tjernlund 6' model # M-6 . The Tjernlund has 530 cfm compared to 435 cfm for the Valuline. You can definitly tell the difference. Also, The fan itself is nearly silent. The sound of the air wooshing can be a little loud though. If need be, you can always put a speed controller on it. You can email the Tjernlund CO. with a comparable fan,(valuline 6') and they will match the price shipped. And no I'm not affilated with the company. Just a satisfied costomer. Tjernlund.com. You can pick up a speed controler at harborfreight.com for $20. Same unit the shops sell for much more.
I would think so. Run the inline fan up in the attic hung with bungees. Use the 6' ducting starting at the scrubber, threw the reflector and up to the cealing. Use the 4' reducer threw the cealing to the fan. You can use two more reducers on the 6' fan or just go with a 4' fan. I Think a better way to do it would be, Run an additional fan with a speed controler, that only pulls threw the scrubber. You would probably have alot more control over your temps that way.would it work in my setup here, having trouble w/ducting