Shop Air Quality Filtration

[Trevor360]

Currently all my machines have Mist collectors and on them, but am looking to further improve the air quality in our 1500SF CNC machine shop. I am thinking about purchasing a few of these “Baileigh Air filtration system AFS 1600” to hang from the ceiling. It looks like these might be more oriented toward woodworking dust, then the oily air we experience in machine shops. Any experience with these and will they work for my application. Is there a better off the shelf alternative?

I am willing invest a few thousand dollars into air filtration, but not trying spend big money on this project.
Thanks

 

[Kingbob]

I have what I think is that exact unit in my shop. We have a large limestone parking lot out side so I got it more for the dust that settles everywhere when we have the doors open. Haven't gotten around to hanging it up yet. The filters do get oily and we all feel pretty good about it but I have now quantifiable way of measuring it's effect.

 

[EndlessWaltz]

what kind of mist collectors you running? Some can get added in after filters etc(HEPA)

 

[cnctoolcat]

Look for a higher-dollar, true commercial grade air filtration unit. You have filters that have to be changed, and others that have to be cleaned. They work well though to clear the ambient mist in the shop.

What we did at the Cathouse was to plumb the mist collectors outside using 4" thin-wall PVC sewer/drain pipe. We only cut one opening on each side of the shop going outside, the pipe's from each machine come together with "Y" fittings near the exit.

We use plastic gate valves from McMaster to shut off the circuits of the unused machines.

 

[Milland]

what kind of mist collectors you running? Some can get added in after filters etc(HEPA)

Yes, check out a HEPA unit (or multiple) if you want to get the air clean. Figuring out where the best "bang for the buck (unit) to hang them is also worthwhile, you don't want to waste the collection potential by putting it in a relatively low air movement zone.

Some HEPA cleaners will use a separate activated charcoal filter, which may pick up more solvent-type pollutants, that's worth some study if it's a concern.

 

[Billy_C]

Depending on the type of coolant and amount that it's getting vaporized, a final HEPA stage can be a big improvement. Also, it really depends on the mist collectors you are running. Haas "enclosure exhaust" should be illegal the way it just dumps the coolant mist into the shop. It's also helpful to take a hour or so with some silicone sheets and try to seal up the major gaping holes in any of the enclosures. There are usually lots of those.

 

[CarbideBob]

Final HEPA may be a maintenance problem and not what you expect.
Absolute first thing is air flow (CFM) and velocity in the pipes.
More than one machine and the pipe has to get smaller to service it.
They sell airflow things which are fans and tell you the draw at the pipe and all around inside the machine.
If the pipe not sized right you put in valves to keep it where you want.

 

[Milland]

They sell airflow things which are fans and tell you the draw at the pipe and all around inside the machine.
If the pipe not sized right you put in valves to keep it where you want.

I hate being a shill for Amazon, but it's good for reference:

Amazon.com : anamometers

 

[Billy_C]

The HEPA filter stage can be a maintenance nightmare but that’s why it really depends on the mist collector. Some are pretty good at removing most of the oily vapor before the HEPA and the HEPA stage will last a long time without having to be replaced. I know ducting it outside is a solution but with “real” mist collectors, that can be 800+ cfm per machine. In most cases that much volume is necessary to keep the vapor in the machine from spilling out onto the shop and properly exhaust the enclosure when operators open the doors. That amount of airflow is enough to warrant an extra amount of markup air that will need to be heated or cooled on its way into the shop. Having “smarter” mist collector systems on the machines that only run when necessary helps reduce the need for extra makeup air but there will always be days that every machine is crankin’. The cost of annual HEPA filter replacements seems small compared to the complexity a huge amounts of makeup air load being put on the existing HVAC system.

 

[Milland]

Better replacing HEPA filters than lungs.

 

[SteveinAZ]

We used 4 of these in 12,500ft2 with 22ft ceilings, they do pretty good at keeping the mist and smoke to a minimum On the super busy weeks, I wish we had 4 more though. We replace the first filter weekly and the second filter monthly, and the HEPAs annually. The weekly/monthly filters are cheap, and the HEPAs were only a bit over $100 each last purchase. The first filter would be fairly brown with coolant/smoke on a weekly basis, pretty proportionate to the spindle hours incurred.

This is our local distributor:

https://www.aramsco.com/advanced-containment-systems-hepa-air-filter-and-negative-air-machine-force-air-2000-ec-fa2000ec.html

 

[Houdini]

We run HEPA filters on all our mist collectors, and our humidity gets too high, So we also have dehumidifiers, that have filters on them also.
Our air is so clean you could breath it
Mistaway HEPA
Commercial Dehumidifier

 

[gregormarwick]

Electrostatic air cleaners are much better than basic mist collectors for pulling oily smoke out of the air, but they require regular cleaning.