Fume Hood Fan Speed Doubt

[didit]

No I get it. The current setup I have is exactly what is in the image you just posted from Ammens. I was thinking about trying a different approach by using Yggdrasil suggestion but I misunderstood his comment. Not a language thing, I was just totally overthinking it. I do thank the both of you for replying to post though. It's really helpful.

Right now the hood does have air flow. I'm going to use the manometer to find the best spot (smoke test too). Then I'll take off the intake funnel and see how much it increases the flow rate. I'll you guys posted.

 

[didit]

One question, why did you reduce the intake side of the fan? I believe that may reduce the volume of air the fan can force through the restriction forming the venturi.

Once you figure out how to quantify your CFM through the hood, try removing the funnel on the intake side to see if you can increase the CFM pulled by the venturi.

You were right. I removed the intake funnel and the suction increased in the hood. I still can't figure out this manometer so the paper guide is showing that there is internal upward air flow. The suction should only get better with finding the best pipe spot and moving the fan closer. Now I just have to figure out how to intake it from the outside in 12 inch diameter.