I understand that breathing in coolant is harmful to the body, wearing a mask saves your lungs but what about when the machine is off and the rest of the shop? For a DIY situation where you need your work table 2 feet from you CNC and it needs to be clean for assembly how do you deal with the mist coolant? On a small mill you could have a vent over head to suck it up? What about something say over a 4X8, 5X10, ect sized router tables? For say the suction style vent what can the coolant go threw to filtered it out of the air or just vent outside? Any thoughts?

Another route to consider is a non fogging mister.
http://www.fogbuster.com/Frame.htm

I built my own for the cost of a couple solenoids. I went to the trouble of downloading their patent. Like all patents, it shows just how to build it. I was very sensitive to mist fog, made my throat and eyes burn. This completely solved the problem.

Karl

To a certain extent, shrouding in the machining area helps reduce mist by giving it a chance to coalesce and condense inside the enclosure.

Use an adequate coolant or mist flow to really cool the chips, otherwise steam can be produced, but this is usually in a heavy machining application like roughing steel and stainless steels.

A commercial mist collector is shockingly expensive. It is a high flow squirrel cage type blower, with a rather large motor, which creates kind of a centrifugal type of mist condenser as it blows the air against the inside surface of a can, and finally exhausts through a large paper air filter. In cold climates like Canada, this is necessary to use these things to save exhausting a huge volume of air outside. But, even then, a little bit of make up air should be used to keep the air from getting too thick over time, so a heat exchanger would be a good option to look for, as well. Again, these exchangers are not cheap either.

worked for a comany that used a fan and vented it up thru the roof , oil did wonders for the tar and gravel roof

I built my own cnc machine and spent about 6 weeks researching mist cooling systems, and trial and error. This caused alot of dilemma for me.

Dealing with air pressure, spray, siphon nozzles and sensitive to the slightest form of blockage, mess, and lots of extra devices - I found it was much easier to use a flood-coolant system.

I have a $10.00 magnetic waterfall pump in a bucket (from harbor freight) connected to a loc-line hose w/ nozzle pointed at bit - so it does a small stream of oil. Run-off is filtered thru a pan back into the bucket.

A pump, some hose, and a pan/drain. That was it.

But most of the time the chips kinda travel as a river out of the way.

Now there seems to be a buildup of chips from time to time, so I added another loc-line hose nozzle as air-only. This way, every now and then I press the button and it shoots air. When I mill plastic, I just turn off the oil, and run air-only.

the machine I ran for a sign company had mist only and it used a vegi coolant I used that on plastic cutting it did magic for making the edge crystal clear. That non Fog coolant system looks interesting, how much did it cost? So with say the flood collant for metals and the non fog for plastic per say that will keep the misting down but im not going to be the only one in the shop would a simple air cleaner be an idea?

flood coolant can work for metal or plastic; though mostly for plastics I found simply using pressurized air @ 25 psi to work just fine.