Ventilation is usually the most overlooked issue when installing a new laser. You must have your ventilation properly installed well before the laser even arrives at your doorstep. With a proper ventilation system, the smoke which the laser produces while laser engraving will be removed from the cabinet.
It is also a good idea to have a dedicated venting port. I have heard stories where a laser was being installed in a strip mall and the owner decided to tap into the existing venting system. This venting system was shared among all of the tenants in the strip mall. For the laser operator, it appeared that the shared venting system was properly removing the exhaust from the laser cabinet, but it was not. The fire department showed up, and the laser owner found out that the exhaust was being distributed inside his neighbor’s bays.