“Vent to air” systems use a simple blower or fan available from your local hardware and industrial supply stores. These types of fans, which come in a variety of powers, basically move the air from the laser cabinet to the outdoors through a channel of duct work.
Depending on where your laser is physically located, the duct work required for this could be rather simple or could be a complex labyrinth of connectors and pipes. If your laser does require extensive duct work, moving the air from your laser cabinet to the outdoors may be a difficult battle to win even with a powerful fan. The farther the air has to travel, the higher power of fan you require. In fact, you may require a fan in the middle of the ducts to sufficiently move the air.
While the advantage of the “vent to air” systems is the simplicity and the inexpensive nature of the fan, there are some other disadvantages. You have to make a hole in the wall or roof which will need to be sealed. External forces such as strong winds can actually force the air back into the building. Plus, there are some additional costs to reheat or re-cool the air you sent outdoors.
It is also important to note that if you choose to use this method, your local and regional municipalities may have certain restrictions to what you can vent to the outdoors.
-Richard Korbyl, Columbia Awards