yet another ventilation/studio question

[joyofit]

Hi all,
I have been reading all the posts on ventilation as I plan to have a studio spot built out in my new home.
I plan on having my HVAC guy build out the venting for me.

I was toying with the idea of a system that has the vent in front of the flame as you see in a lot of the Itailian studios. I have seen some interesting looking homemeade systems here as well.

Otherwise the way I was thinking of setting up my room there is not a lot of headroom to set up a hood.

The wall I will be facing my table and setup has a slanting ceiling and it is the best place to bring in the line for the propane and vent to the outside.

Or I could place my table at the end of the room but I would not have much width that way (6ft). And the airconditioning vent would be above and to the right of my workspace.

Is there a good way to have a vent on the ceiling with a aproxmitely a 60 degree slant?
I prefer not to enclose my work area on the sides, will I have a harder time getting good ventilation?
Whats the best way to get a quiet system?

and finally...
the formula for CFM's if I do not put sides on my work area, What formula would I use?

Thanks for any imput,
Char

[Dennis Brady]

Originally Posted by joyofit

Hi all,
I have been reading all the posts on ventilation as I plan to have a studio spot built out in my new home.
I plan on having my HVAC guy build out the venting for me.

I was toying with the idea of a system that has the vent in front of the flame as you see in a lot of the Itailian studios. I have seen some interesting looking homemeade systems here as well.

Otherwise the way I was thinking of setting up my room there is not a lot of headroom to set up a hood.

The wall I will be facing my table and setup has a slanting ceiling and it is the best place to bring in the line for the propane and vent to the outside.

Or I could place my table at the end of the room but I would not have much width that way (6ft). And the airconditioning vent would be above and to the right of my workspace.

Is there a good way to have a vent on the ceiling with a aproxmitely a 60 degree slant?
I prefer not to enclose my work area on the sides, will I have a harder time getting good ventilation?
Whats the best way to get a quiet system?

and finally...
the formula for CFM's if I do not put sides on my work area, What formula would I use?

Thanks for any imput,
Char

The "formula" commonly recommended is 125 times the surface area of the hood but that is only a guideline. The closer the vent outtake is to the torch, the less fan capacity is needed to extract the fumes.

The kind of system you see the Italians using for glasswork is also the kind of system you'll likely see in commercial shops that are carefully inspected and required to meet rigid safety standards. It may be different in different places, but where I live, the 125 guide is completely ignored. The only standard accepted is the smoke fume test that confirms extraction of all fumes.

[Dale M.]

The "formula" commonly recommended is 125 times the surface area of the hood but that is only a guideline.

Its not "125 times the surface area".......

It's 125CFM per square foot of "face opening" of hood.... And it is the OSHA recommendation for a Class "A" chemical fume hood.

Dale

[Dennis Brady]

Originally Posted by Dale M.

Its not "125 times the surface area".......

It's 125CFM per square foot of "face opening" of hood.... And it is the OSHA recommendation for a Class "A" chemical fume hood.

Dale

A 12" x 12" hood with 125 cfm fan mounted directly over the torch might work great but would be pretty much useless 3 ft away.

The 125 figure is meaningless unless related to distance from fume source.

[Dale M.]

Your argument is pretty funny since about a month ago, you were asking me about ventilation specifications......

http://www.lampworketc.com/forums/sh...4&postcount=14

Dale

[Dennis Brady]

Originally Posted by Dale M.

Your argument is pretty funny since about a month ago, you were asking me about ventilation specifications......

http://www.lampworketc.com/forums/sh...4&postcount=14

Dale

I 'spect you'll be equally amused by the smoke test videos demonstrating the erratic reliability of the 125 guideline.

[Dale M.]

Actually the ONLY thing you have ever said that makes any sense is validity of a smoke test..... Though I have not see your videos...

Dale

[joyofit]

thanks for the input.
I will do the math and figure out the CFM needed for the venting.

Maybe I should post in studio as I would love some more experienced people to weigh in on what type of vent I should consider given the space I have to build it out in.
With a sloped ceiling ( i will be in a space with the roof slopes about 60 degrees into the wall I will face as my workspace. ) Any opinons on venting "italian" style or a hood above?

Thanks,
Char

[Dennis Brady]

Originally Posted by joyofit

thanks for the input.
I will do the math and figure out the CFM needed for the venting.

Maybe I should post in studio as I would love some more experienced people to weigh in on what type of vent I should consider given the space I have to build it out in.
With a sloped ceiling ( i will be in a space with the roof slopes about 60 degrees into the wall I will face as my workspace. ) Any opinons on venting "italian" style or a hood above?

Thanks,
Char

There are still more tests to do, but smoke tests so far demonstrate the closer the hood is to the torch, the more efficiently the fumes are extracted. The "Italian" method doesn't necessarily work better, but it does do the job with less fan capacity then an overhead hood.

[d2063614]

when you fined out the best distance from torch to hood let me now i still have to make mine and dont want it to far up. but il obviously do the smoke test with wet news paper

[Dennis Brady]

Originally Posted by d2063614

when you fined out the best distance from torch to hood let me now i still have to make mine and dont want it to far up. but il obviously do the smoke test with wet news paper

I'm hoping we can find some "formula" that equally, and with reasonable accuracy, considers hood size, distance from torch, and fan capacity. Any of those three factors is meaningless without considering how it's affected by the other two.

[d2063614]

make a formula and become a math metition and make money well doing this nah im just kiddin

[Dennis Brady]

Originally Posted by d2063614

make a formula and become a math metition and make money well doing this nah im just kiddin

If you don't got the math, you gotta SWAG it.

(Scientific Wild Assed Guess)