Cracked tube guy here. Here’s my experience from 3 separate setups at 2 different makerspace locations (same org, just found a better building across town):
Setup 1: Venting directly outside with an exterior louvered vent under an overhang
Setup 2: Shared venting (with a bathroom) with a blocking diverter and a blast gate
Setup 3: Dedicated venting with a blast gate and a louvered vent without an overhang
Setup 1 (old space) used flexible 4" dryer tube between the laser and blower, then solid ducting to an existing exhaust port on the wall (intended as kitchen exhaust), and worked OK…until the winter of 2013 brought a super-hard freeze (by our standards: -18F) to our area. Even though the exterior louvers were closed and the space was heated (50s-60s when no one was there), enough cold air came in to freeze the coolant water in the tube.
Setup 2 (initial setup in the new space) had the same dryer line running between laser and blower, then switched to solid ducting to run to a ceiling vent that went to a common exhaust worked well for the laser, but not so well for the bathroom. Even though we made sure the diverter was doing its best at keeping the exhaust airflow from coming into the bathroom, it still smelled like fresh hot laser in there. I can’t recommend having a laser share an exhaust with anything, even if you have a good diverter.
Setup 3, the current setup, returned the laser to a dedicated exhaust line, put a better louvered vent on the exterior wall, switched ducting from using any floppy dryer tube to solid aluminum flex duct, and has the blast gate after the blower on the exhaust route. Some water got blown into the exterior vent during a particularly heavy storm, which the gate prevented from flowing further into the blower. We’re still trying to figure out whether we need to change this, or are fine, since that type of storm almost never happens (we’ll end up fixing it, but other projects have taken precedence). This setup works pretty well so far.
Interesting. Given that the GF is supposed to have a closed loop cooling system, I wonder if it will ship with cooling water already in it? Not asking the question but just thinking out loud. Live in the WV mountains. Wouldn’t want a delivery in January unless the acceptable storage temp was at least -10F.
Since our shop also contains a large selection of wood working tools, we have decided to move our GF into the office, and run some of our venting out to our sawdust collection system. Our collection actually gathers outside the building. Granted, this will likely reduce the moisture problem since we have a complete shop between the elements and the GF, my suggestion would be a manual blast gate. You already have to be present to run the GF, what’s one more step in the process to open the gate?
Just need to glue in some pvc or other material ends maybe even a union on either side and the nice part about cutting it is you can fit it easily to an odd ball size system if you already had a shop setup or different sizes on either side.
I haven’t personally tried these yet, but I think Our Glowforges deserve something like this: http://www.rockler.com/ivac-pro-4-in-blast-gate-starter-pack. Don’t you? The starter kit comes with 2 gates, so I guess I’d want to use the other one to suck fumes from my 3d printer
Water would be a bad coolant choice in my climate. Especially for shipping. I don’t expect my storage temps to go below freezing once it arrives, but I’d hate to worry about my laser freezing if something goes wrong with heating in the space I’m using. I would imagine propylene glycol could be switched out in most applications where water would be used.
