On the subject of ventilation, butane is heavier than air, so overhead hood vents don't work very well. Our indoor ventilation cabinet has both a bottom and a top exhaust, for both lighter and heavier than air components. It also is fully enclosed and draws outside make up air.
The automated Mk II also has its own bottom exhaust cabinet, but we don't do any open column butane extraction indoors, even in an exhaust cabinet.
Despite the cabinets, we don't run the manual Mk I or III's indoors. Only with recirculating fully automated Mk II, in a specially constructed cabinet, in a specially constructed building, standing alone away from other structures.
It will only leak butane by accident and the room exhaust rate is one complete air exchange every three seconds in a spark free room.
Our insurance company won't insure an extraction lab, that is part of a residential structure, nor an open column extraction operation, so ya'll might also give some thought to the financial repercussions should something go wrong, go wrong, go wrong..........
An age is called Dark not because the light fails to shine, but because people refuse to see it.
Believing is seeing and ignorance is bliss until it bites you in the ass!
Fervor is the weapon of the impotent. The harder the sell, the poorer the product.
Alas, my ignorance abounds; the more I've learned, the less I know that I know..........
Thou shalt seek and respect the opinions of operators, even unto the third helper, for theirs is a wisdom unknown to technicrats.
Wise men learn more from fools, than fools from wise men.
In my dotage I finally discovered that the secret to putting on pants both legs at a time is sitting down.