Somebody tell me what fan to get!!!

[ginkgoglass]

I need a 5000 cfm fan to cover the bench space for 4 crickets and a Mirage. I've had a ventilation expert come over here and tell me I can do a fan in the roof at 600 cfms for 8 to 10 air exchanges an hour. I know that is not adequate based on my calculations of 96 X 60 inch (8 x 5 foot) island workbench.

Feeling really overwhelmed what fan to get. I would like it to be quiet if possible and can vent through a window to a hood or through the roof.

I will send some glass and a maybe some other goodies to the person that picks one out for me!

Hellllppppp mmeeeeeeee . . . .! I'm serious, really serious.

[ROC]

I have no idea, Lana, but have noticed a lot of folks have gotten theirs from Grainger. Wonder if they could help you decide over the phone?

[chrisann]

Hi Lana,
I can go check min again I thought it was 1200 but maybe I was wrong. It is a double squirl cage type and I have it for 5 torches. Brent has taught here using this system with 5 torches running and we have had no trouble with any kind of fumes or anything. what kind of hood and or intake system are you planning? that may play a part in having to have a much stronger fan I would imagine plus how far it has to pull. for quiet I would rec that the fan be outside as it greatly reduces the noise. I didn't have an HVAC guy design mine so it might not meet their standards but it certainly does the job. Good luck
chrisann

[NMLinda]

The best resource I've found for figuring out what fan to get is

mikeaurelius.wordpress.com/ventilation-primer/

Based on that resource, an open-sided 8x5 area would require a fan size of

5000 cfm = 8' x 5' x 125 which confirms your own assessment.

Your HVAC guy is recommending something way underpowered for the safety you'll need. An air exchange of 8 - 10 room air changes per hour isn't the way one needs to spec systems for torch work. With the torch running, you want smoke from a smoke test source (held nest to your torch) to exit your exhaust fan in less than 2 seconds, one second is ideal, otherwise you're at risk of breathing either the spent fumes of the torch's combustion process or fumes from your glass project.

A 5000 cfm is likely going to turn out to be a relatively large, industrial squirrel cage fan. It will likely be heavy, as well as noisy, so mounting it outside your studio on your roof is likely to be your best bet.

I've never had reason to look for a fan that big, but I've seen squirrel cage fans on the Fantech website that are over 2500 cfm. Fantech might be a place to start. Below is a link

http://www.fantech.com/

Linda

[Dale M.]

Also consider most HVAC people do not know and understand anything about torch/studio ventilation...... The 125 CFM per square foot opening number is taken from Class "A" fume hood design/specification used in chemical and biological and manufacturing adjournment where where highly toxic elements and gasses are present.....Do Google search on "fume hoods" and read up on the specifications for health and safety and institutional users...

HVAC usually deals with basically moving enough air around to keep "room" heated/cooled and enough air exchange to basically have a health breathings space. That does NOT include heavy contaminates being PRODUCED in room (Nitrogen Oxide (NOX) carbon monoxide and heavy metals from heating and fuming (with silver and gold) of glass).......

Dale