welding room ventilation

Hi All,
It was brought up two weeks ago that the welding room ventilation should be improved. I would like to get a conversation going on the mailing list here so we can formulate a plan.

Looking at: http://www.industrialfansdirect.com/CFM_Calculator.html

it seems that the minimum cfm required is about 1400 (16’x16’x22’ - which the height is not 22’ in the entire room so that is overestimating). If we want to with typical cfm, it is closer to 1900cfm.

Going with the bare minimum here are a couple options I saw - granted this was just a quick look on ebay and grainger - please suggest other options:




or two of these: http://www.grainger.com/product/DAYTON-Exhaust-Fan-1HKL4?s_pp=false&picUrl=//static.grainger.com/rp/s/is/image/Grainger/1HKL4_AS01?$smthumb$

Again I am not trying to spearhead this project, merely getting the conversation moving about it. I will need someone else to actually take over the installation/ordering/etc as I will likely be unable to do so by the time this needs to be done.


What is the square (or cubic) footage for this room?

I’m down at the space, so I walked back there with a tape measure. The room’s about 16 by 16 by 18 feet.

There are specified build codes reg a regarding ventilation for rooms used for welding and such “dirty rooms” I will have more on that tomorrow regarding what we will need to be up to code as early as tomorrow if not: by Tuesday’s meeting

According to OSHA regulations, when welding and cutting mild steels, natural ventilation is usually considered sufficient to advoid exposure provided that:

  1. The room or welding area contains at least 10,000 cubic feet (about 22’ x 22’ x 22’) for each welder.
  2. The ceiling height is not less than 16 feet.
  3. Cross ventilation is not blocked by partitions, equipment, or other structural barriers.Note: When welding must be performed in a space entirely screened on all sides, the screens shall be so arranged that no serious restriction of ventilation exists. Screens should be mounted so that they are about 2 feet above the floor (unless work is performed at a low level and the screen must extend to the floor to protect nearby workers from welding glare.
  4. Welding is not done in a confined space.

Spaces that do not meet these requirements should be equipped with mechanical ventilating equipment that exhausts at least 2,000 cfm of air for each welder, except where local exhaust hoods or booths, or air-line respirators are used.

the recommended number of air changes in one hour for a welding room is 15-20, which is where the earlier minimum requirement I posted is from. so - 16x16x22 cu.ft x 15 air changes/hr divided by 60 gives you 1408cfm. seeing as the welding room is less then 10,000 cubic feet, if we want to be up to OSHA standards, the bare minimum would be at least 2000cfm per regulation 1910.252(c)(2)(ii).

Thanks, I am also talking any specifics regarding local laws etc, my father has all this recorded at his work ( he works with this stuff for a living and is obessed over regulations)

Thanks for doing all that research and posting about it Tiffany.

And thanks for investigating any other local regulations Daniel.

A lot of people use that space for various things, and proper ventilation is so important!

Ok I admit that I blurred over the technical stuff.

Would a squirrel cage blower/motor (like from a smallish house furnace) work? I have one. and will give

Probably not unless it was a very large squirrel cage blower, like medium to large house. I think with the way things are set up, a different style extraction fan would make sense but this is something to investigate. I can get big blower motors like the one used for laser vent for free from HVAC friends if the one you have isn’t big enough.

It was recommended that squirrel cages be used (we also have a second one above the lounge not being used) as the fumes from spray painting can become explosive and that fume cloud contacting a motor would be bad.