Air Exchange Rate for Welding Shop 1

[flowweld]

Does anyone know the general rule of thumb for an air exchange rate inside of a welding shop? I am trying to design a system to clean the air in our welding shop and cannot come up with the simple baseline. Ive spoke to several manufacturers / suppliers of air cleaning systems and no body will flat out tell me. Backing into the data ive collected the numbers range from 2 to 15 air exchanges per hour. I found one table on engineering toolbox that says 12 to 15. The one very helpful duct collector manufacturer tells me industry standard is 5 to 6. Any help would be appreciated.

 

[Compositepro]

It is not only air change rate that is important. That is primarily to remove fugitive emissions. As much as possible, weld fumes should be exhausted directly outside (don't weld in front of the air in take for the air conditioning).

 

[cdxx139]

Industrial Ventilation will have the recommended requirements.

Is it a bench hood? If so, it wants to slots sized at 2000 fpm connected to a plenum behind it sized at 1000 fpm.

Like stated above, you dont want to provide air changes, you want to exhaust the contaminants where they are happening.

Good luck

knowledge is power

 

[mauricestoker]

As mentioned above, room air changes are pointless other than general scale. The materials used (electrode, work piece), containment, and capture velocity and distance (must have one with the other) will determine flow rate. Depending on the analyte and whether it has an associated ACGIH or OSHA Z table entry: some analytes have a very low exposure limit and action level.

The ACGIH and ANSI Z49.1 should provide additional guidance. Depending on the analyte, I have typically used (with enclosure) 9" capture distance and 100 fpm capture velocity.

 

[berkshire]

You are beter of with point of action removal systems.
Check with Plymovent Inc.
B.E.

 

[berkshire]

Also when you double post please indicate that you have done so with a link to the other post.( ref your post in Welding Bonding and fastener engineering)
Double posting simply dilutes the answers you are going to get and annoys some of the members here.
B.E.

 

[willard3]

ACGIH "Induatrial Ventilation" covers welding exhaust and it's requirements.

American Conference of Governmental Industrial Hygienists = ACGIH

 

[cdxx139]

Thank you willard, ACGIH is what I meant by "Industrial Ventilation". I guess I don't use it often enough to remember.

knowledge is power