I set out on this grow to see how much I could get for the least amount of money. I try and help med card holders grow and get experience for as cheap as possible so everyone has access to meds without a dispensary. I’m gonna be pushing 4oz with 90w. I decided to try and build a diy passive exhaust so I bought the $9.99 6" clip fan from Amazon
Comfort Zone CZ6C 6-inch Quiet Portable Indoor 2-Speed Desk Fan with Clip and Fully Adjustable Tilt, White https://www.amazon.com/dp/B000U9V47E/ref=cm_sw_r_cp_apap_sdnuJ57vEbFQG
I bought an inside dryer vent kit from Lowe’s $15.00
I attached the inside part of the air box to the fan cage with zip ties.
Then I wrapped the air box with clear packing tape to bottleneck the air flow
I suspended it in the top of my tent with plant ties wire
This is a top view
I cut the expandable dryer hose in half and ran one piece out the back for passive inlet with a crown Royal bag as a filter.
Then I clamped the other piece to the exhaust with a crown Royal bag as a filter.
I put baby powder on the exhaust filter outside and it blew it into powder and filled my room lol. So I’d say it works. Now keep in mind it works for me because I’m in a 3x3 or smaller. I don’t believe if you tried a 4x4 and up you’d get sufficient cfm air displacement. Thanks guys for looking.