Question on hood vents

[rdhjanice]

can someone tell me how many cfms in a fan would be needed for an area if boxed in by the 30"fan (Top) , sides 24" tall and a metal sheeting for backink would be suffecient, also has any one heard of those ductless vents, air is filtered using a charcoal filter, just wonder if those might work here is a link to one although it only has a cfm of 180. any help would be great.
http://www.ventingdirect.com/index.c...rhreviewbanner

[NMLinda]

I'd recommend you check out

http://mikeaurelius.wordpress.com/ventilation-primer/

as well as the safety and ventilations sections of the Art Glass Answers website.

Ductless fans will NOT work! They're just simple grease traps. What you're trying to do is evacuate the combustion by-products created by your torch, such as NOx products.

You'll find from the calculations that 180 cfm is nowhere near enough cfm. For the opening you described, you'll find that you need closer to 600 cfm. even with a back.

Besides those two sites, there are many good threads discussing ventilation both here in the studio forum as well as safety forums. They're worth researching - will help you get a better idea on how to implement as well as size.

Good Luck!
Linda

[rdhjanice]

thanks linda that site has alot of good info, i will definitley need help.