From the Manual…
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.
Another forum link.