Inline "pot" fans and make up air

[Nick Andraka]

I guess indoor pot growing is the thing, 99.9% of the exhaust fans are market towards indoor growers.
Anyhow,
I have found a ton of inline fans, ranging in price and quality.
The exhaust port on my Epilog is one 4" port, I plan to use a 4" to 6" transition ell right at the port.
The 6" inline fans are 350-400 cfm, the 8" are ~700 cfm

Machine is in the walkout basement, against the back wall, covered screened deck is against the back of the house, fan would be between the joists of the porch, out of the weather.

My exhaust path would be 4" too 6" sweeping ell out the back of the machine, 6' straight 6" duct up the wall, 6" sweeping ell turning out through the band board,
Fan directly outside, then 8' duct straight out of the fan.

Question - I would prefer to use an 8" fan with a quality speed controller, it would be reduced to 6" on the intake, the 8' of exhaust would be 8"
good or bad idea to reduce the intake?

My house it pretty tight (spray foam), I am running an ERV.
I am thinking I will need make up air, anyone find they need makeup air with their setup?

Nick

[Joe Pelonio]

I am using a Fantech 8” from Grainger, that I bought in 2004. It’s reduced to 4” in and out and has been great all this time, no problems, no makeup air, but in large rooms. First it was in my 1900sf light industrial building, up to the drop ceiling and then 25’ out to the front. Now it’s in a 400sf room over the garage in my home, just a couple of feet exhausting through a window where I put in a panel with dryer vent. I just don’t shut the door tightly.

[Nick Andraka]

Joe,
Thanks.
So when it was set up in the commercial building the entire length was 4" duct?
I think I am going to use:
https://terra-bloom.com/collections/...ng-710-cfm-75w

It appears to have a decent (not a rheostat) speed controller, I will adjust it down to where it needs to be to keep the machine clear.

I was not sure how these in line fans would act being reduced down in duct size.


Nick

[Joe Pelonio]

Yes, I used flexible aluminum up the wall, then PVC out to the street. No speed control on mine, it’s always full speed but no problems.