First I would like to say hello to all. I'am new here and after hours and hours of reading all I can say is thank you all for all your hard work and commitment that each and everyone has provided to this forum.
I am so confused so I figured I would ask the experts.
I have a shop that is 13ft x 10ft x 7 high it's your typical "steel backyard shed style" that is insulated.
At one end I have a bench that is 3ft deep by 8ft long. I will be running 2 torches. 1 Nortel Minor and 1 Red Max with Mega Minor basically 2 stations.
Is 1 1500 cfm attic fan with no ducting mounted on the wall above my bench acting as exhaust adequate ventilation to run both torches simultaneously? NO HOOD
My incoming fresh air will be made up by leaving the 30" x 72" door open at the opposite end of the shop with a stand up 14" oscillating fan pushing fresh air from behind me until the weather turns and then I realize I must equalize the incoming to match the exhaust.
How high above my bench should the fan be mounted ? 24 to 29 IN. ?
2nd scenario could be a large squirrel cage fan with a split Y or T duct then branching off to each station with duct size of approx. 8-10 " each with a 90 * elbows pointing towards each torch. Same incoming fresh air scenario as above.
NO HOODS
3rd scenario could be a hood or hoods and what suggestions would you have for those?
Size? One large one , 2 smaller ones or ? Enclosed bench top ?
I will be doing both Boro and soft glass and often at the same time ( as my 16 yr old daughter will be at the 2nd torch. ) Also some fuming . Budget is definatly a consideration but a few extra $ to stay healthy can be found somewhere.Can I bring the ducted air under my bench off the same wall as my exhaust ? There would be approx. 6 ft separating floor duct to wall exhaust fans . How large an intake would you say 8" min ? What cfm fan do you recommend for the intake ?
1 intake per station or 1 for both in the center of the bench?
Shall I build custom hoods? If yes , what size hood would you say I should build per station ?
Again the bench being 3' x 8' x 36" tall . I live in the interior of B.C. Canada . We have a climate that resembles Northern Cali most of the time . 100* F in summer and maybe -2* - -8 * F in winter .
Sorry for all the questions i fully understand how important health and safety is and after being a Goldsmith for 28 yrs starting in the mid 1970's my lungs are already telling me I should have payed much closer attention to this exact topic 28 yrs ago.
I'm sorry for the long winded question I just figured I should cover all the bases at once.
I found this
http://www.artglassanswers.com/forum...opic.php?t=150
this is what I was asking . In the top set of sketches can I bring fresh air from the same wall as the exhaust ?
So I would be bringing in some make up air as you suggested ( see Figure 2 ) but using the set-up for exhaust as Figure 1.
Maybe have my exhaust pointing up with 90* elbows for each station exhaust.
" It seems he says the intake area from under the bench in Fig. 1 is in the contaminated zone. " But as I sse know I can take fresh air intake from the sides of the building.
I don't think roof venting as he has in Fig. 2 is an option for me.
I don't see a fan on his intake in Fig.2 is it just direct draw so to speak? While he is still pulling fan drawn make up air in from behind ?
MY FAVORITE 
After much thought and planning,reading and searching I think I will do my ventilation similar to this.
http://i737.photobucket.com/albums/x...dimagesphp.jpg
I will have 2 x 30" x 30" x 24" hoods with 8" ducting per station.
Along with this I will have 2 6 " side wall mounted intakes just off the floor with grates on my bench top. Each station will have 2 fresh air intakes so 4 total .
I will have the hoods 24'' to 29 " above the bench.
Can someone please calculate the cfm size of fans I will need for each station/hood.
My calculation comes to somewhere between 800- 950 cfm per station.
Does anyone have any other suggestions?
Does this sound correct ? Or is that way overkill ?
Maybe this is overly complicated ?
Better safe than dead I say.
Am I on the right track. And Mary I love your set-up BTW
I have to have my ventilation finished this week as my glass order is coming.
Thank You Dale M and Mary K for you insites and ideas, and I hope you don't mind me using your images.
Please help with ventilation'
