Greetings! I've been absent from this site for years, took a long break from lampwork to get some other stuff done, and now I'm back at it and back here! And I have a question!
I have a big (ten inch diameter) squirrel cage fan with two settings. Even on the low setting, I know it pulls a massive amount of air; just for fun, we turn it on, close all the windows in the house but one (several rooms away), and can feel a serious breeze. I used to just rely on the fan sucking the air up and out, but I can tell that this time it wasn't cutting it (sore throat and chest achey-ness after a few days. maybe I'm getting more sensitive in my old age?). So we hooked up an old kitchen range hood, which can be seen in the photos. I did the incense test, and although I couldn't smell it from where I sit to work at the torch, a bunch of the smoke was wafting AROUND the hood and up into the backside of the squirrel cage fan! Obviously, the path with the greatest pull is to the backside of the fan, not up through the ducting.
Now, I have read a bunch of these threads, and it appears that I should be using smooth ducting instead of the flexible. Could that make so much of a difference that there would be more suction through the hole in the top of the range hood, rather than the back of the fan? AND/ OR is the problem that my fan is inside the house? I'm looking at a bunch of photos and not really seeing any squirrel cage fans inside.
I'm sorry if this photo is too small. I tried to post larger, but the site said I could only post up to 80 kilobytes. I suppose I could do a thumbnail and if you click it, it would get bigger? (not very computer savvy!)
Oh, some added information...
The bottom of the range hood is about 14 inches from the top of where the flame would be. It is completely over the torch and the flame and a couple inches from my head (it actually touches the top of my head if I lean forward). With the incense test, if I raised the incense up a few inches, it went directly up through the hole. But I don't want to lower the hood too much or I'll constantly be knocking my head into it.
I would love some input on this issue, please! Especially since it would be great to solve the problem before my husband has to do even more work with experimenting!