Should I cover the duct and disconnect?
Im afraid the freeze will brake or burst the laser tube… or lense…
But that means I will have to cancel all my next week orders… 
I will if that means my glowy will get any damage…
This weather is never seen in Houston don’t know what to do…
Some people install a blast gate between the machine and the wall. If you do that and then close it when the machine is not in use you should be ok. If you decide to disconnect it you can still hook it up to use it then disconnect when done.
When it gets really cold where I live, I disconnect the vent when I’m not using the Glowforge. Also, I have a blast gate that stays closed except when the Glowforge is operating.
I do have a blast gate… I just don’t know if its safe to cut under this extreme cold conditions… cause it says that to to protect it not use it under 40F / 5C
While you’re using it, the Glowforge will take in room air and vent that to outside. As long as the room is warm it shouldn’t be a problem. Close the blast gate when you’re finished. You can also leave the lid open when you’re not cutting to help keep the room air circulating in the Glowforge body.
It has its own sensor so if it gets too cold inside the machine it will stop itself (yellow button warning).
I doubt it’s that cold inside your house - so as long as you close the gap between the cold air and your machine when you’re not using it, you should have no problem using it when you want to - since it’ll be actively blowing air out that hole when in use 
Thank you so much for posting this
As @vero.diazdelavega pointed out, there are specific environment conditions you’ll want to ensure your Glowforge is in, so that it performs within specification.
Inside of the manual, we highlight disconnecting the host from the rear of the Glowforge for cold temperatures (or hot!)
Extreme temperature or humidity
○ Temperatures below 40 degrees Fahrenheit (5 Celsius) or over 120 degrees Fahrenheit
(48 Celsius)
○ Extreme humidity conditions (below 10% or more than 75%)
○ If venting outdoors, ensure that changing conditions do not cause extreme temperatures
or humidity to enter the Glowforge unit through the exhaust hose. Disconnect the hose
from the outside air when the Glowforge is not in use.
I hope this information helps!
It’s been a little while since I’ve seen any replies on this thread so I’m going to close it. If you still need help with this please either start a new thread or email support@glowforge.com.
