Fresh Air

Thanks for that 4 to 5 turns per hour is easily achieved, but will wait to see if there are any further comments

Air conditioning does not affect the volume of the room.

Needless to say, any aircon needs to operate with filtered air.

<...nearby volcano...> Is the factory in the right location for long-term operation?

one good volcanic blast can ruin your entire day, an air filtration system can address the ash component but will do nothing to neutralize the gaseous emissions. you're really biting off a lot here!

SolarEagle is right on the mark here.

First off there is no such thing as Fresh Air a common mistake we all make....it is out side air, as I learned the hard way by saying I would bring in "fresh air" make up into a law office in San Francisco. It ended up fresh air........ with heppa filtration, ionizers, and humidification but it cost me 10k to accomodater the "fresh Air" Clause in my proposal...now I bring in OSA.

Well that rant is over...take a look at these standards they will supply you with the knowledge and answers you need to your question.

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&sqi=2&ved=0CCoQFjAA&url=http%3A%2F%2Fwww.ashrae.org%2FFile%2520Library%2FdocLib%2FPublic%2F20060815_200652210714_347.pdf&ei=4-JzUpypM-a2sASJ6oG4BA&usg=AFQjCNEIKAeYuBV-98VHMilFPxKD-eAwJQ&sig2=Gsb-gGaiSFTXVNIjRoU2IA

ASHRAE ADDENDA Ventilation for Acceptable Indoor Air Quality

Have a great day.

You have the figures you asked for. That's good.

BUT.....

Can't you relocate?

Apart from 4 or 5 people what else inside the building would need dust free air?

Filters need cleaning and possibly eventual replacement. Who would do that? Is it really that hard to sweep regularly?

The assumption should be that relocation is not an option, The question addressed a problem about how to adapt. there are disasters happening all over our globe and the popular reaction is to move to greener pastures? This is not a practical solution, Think refugees More better that we learn to adapt The question is How many changes of air would be practical to keep 4 or 5 people comfortable inside a sealed factory building pressurised with filtered air?

As to what else would need fresh air - any machinery inside will. I was under the cloud when Mt St helens blew and the ash we got was two types. One looked like the bubble filled glass insulation after taking a hammer and rolling pin to it. I could hear the little 'tink" as it each particle landed on cars. The second type of ash was like flour and got everywhere; it floated very nicely despite being rock. Both are very abrasive; Some folks wiped that first ash off their car like it was ordinary dirt and ended up with many scrathes to the paint. As a bonus I got the next day off work as a "volcano day".

Good! Everybody and everything need fresh air!