Cold Air From Machine

I tried searching this and didn’t seem to find what I was looking for…

I have the GF Plus. I feel cold air coming off of… or out of(? I can’t tell) my machine. That’s normal right? I notice it from time to time but seeing as I just redid my hose and stuff I wanted to double check.

While it is printing? That is not normal, the machine should be under a slight vacuum, i.e. sucking air in while printing.

While not printing, there really shouldn’t be any noticeable airflow.

Assume it’s coming from backflow from the vent?

The general theory is that louvers or a blast gate or disconnecting/sealing is the way to prevent that.

Oh and the second thing is “why would we care”. Well in theory you could get lots of cold air from outside that would make your GF too cold. I combat that in two ways. I have a louvered dryer vent that prevents much backflow, and when it’s set to get really cold I leave the glowforge front door open.

Like before I put the GF to bed, I open the lid, flip down the front, and set the lid back down. That way room air circulates freely and the GF stays warm.


Not while printing. Just sitting. I have a blast gate. It’s like… not gusts of air but it feels like my machine is a mini ac. Like it’s not terribly cold out right now. My machine has always put off some cold and I assumed that’s cause it has that advanced cooling or whatever…

If your home is “leaking” warmer air through windows or attic, it would need to draw fresh air in from somewhere. Sounds like that might be the problem.

You might put a blast gate right at the machine for convenience, and close it when not in use.

Edit - as suggested above. :slight_smile:


Agree with @evansd2, sounds like air sucking in from the outside. In addition to not wanting too cold (or too hot) air getting sucked through it, you don’t want too much moisture. I vote: play it safe and either put in good blast gates or rig your venting so you can easily disconnect the forge from the outside air entirely when not using it. If the air’s coming in even when the fan is running, add an inline fan to help.


Nope, physics come into play here. Your GF net produces heat. The cooler is directly tied to the laser coolant and you shouldn’t feel any of that. The heat that is extracted from the coolant (and the heat generated by the electricity and what it takes to run a peltier cooler*) gets radiated inside the machine, which then the ventilation whisks away. If you’re feeling cold it’s coming from somethng else, either backflow (my best guess) or another draft just coincidentally near the GF, or maybe a hidden ac vent you don’t know about or IDK what :wink:

* Yes I know I am simplifying, I left out heat byproducts of the rest of the electronics. Lots of very technical people here will be like “yes but, you’re leaving out x or y”, that’s not the point here tech people :wink:

EDIT: here’s a post about my louvers


Yeah what they said - there are a few designs for blast gates on here (or you can buy them too)

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