A Note about Hot Weather Glowforge deliveries - Temp Alerts!

Not sure what you mean by this. Are you cooling the air that you’re then feeding into the GF? Otherwise not sure how you get cooler air than ambient with the passive cooling of the GF (yeah, it’s fan assisted, but it’s just going through a radiant heat exchanger and that heat exchanger is dumping hot air into ambient so it doesn’t seem that the coolant could be cooler than ambient). The peltier cooling of the Pro should be able to drop below ambient because it consumes power to create a cooling differential.

Mine hasn’t worked about 78F. I’ll have to check it tonight when I get home. Working on my chiller tray anyway. I have an infrared temperature wand I use to point & shoot temps so I’ll see what the heat exchanger says.

Hmm, seems a good way to wear out the pump and fans running them continuously.

If it is shiny metal an IR thermometer will read low unless it has a way to specify emissivity.

It’s flat black.

Ideal then.

No. Delivered air feels cooler than static ambient. I’m not an engineer and most of fluid dynamics is over my head, but I would guess it has something to do with atmospheric constituents especially moisture convecting.

Regarding the pump and fan running slower after a job, there is still heat in the tube and coolant after the laser stops, so it makes sense to me.

Yes it makes sense until things are cooled back to ambient but seems wasteful to run them permanently.

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An argument for not leaving it on if you don’t anticipate using it soon. No need to have it poised to do nothing - when it takes only a few minutes to home itself.

Yes certainly what I would do as I will use it rarely but for a business or a hacker space it might be more convenient to leave it on all day.

Got it. Thought there was some magic involved. The air isn’t really cooler than ambient as the heat exchanger experiences it, just us skin covered organisms :slight_smile: There may be a small amount of increased heat transfer capability as it moves the warmer than ambient layer off the heat exchanger and replace it with moving ambient (but cooler) air that may be able to absorb more heat than a still layer of air because of the wider spacing of molecules in the moving air stream. I don’t expect it’s likely very much but I think I’ll give it a shot tonight because maybe I’m underestimating the value of moving the warmed layer off the heat exchanger.

I think what you’re trying to say is that the evaporative potential is cooler. But that potential doesn’t exist on most hard metal, because there’s relatively little or no water vapor to evaporate. Unless it has water covering it… like on a heat exchanger.

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Convection carries the heat away from anything, right?
In the movies an astronaut freezes instantly if he takes his helmet off, and that’s not right. (of course the pressure differential would kill you right quick) it would take minutes - just because there are only a few scattered atoms to carry the heat away. In static atmosphere there are a lot more atoms in contact to convect, increase the contact by forcing more contact (fan) and convection is increased.
At least that’s my layman’s understanding. (flicking on the Bat light) Calling one of our resident physicists @jacobturner!

Not any more than the medium can hold based on the thermal differential. Pretty sure thermodynamics won’t allow you to take 80 degree air for instance, send it through a fan to accelerate it (wouldn’t this warm the air?) and have it cool an 85F surface (heat exchanger) to 77F.

If there is a large temperature difference in the first place - like a surface that was 103F and the air was 80F you could expect it to cool faster with a moving air stream than a still one as you’d be continuously removing the warmed boundary layer between the hot surface & the moving air mass.

But then Bill Nye I’m not.

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I can’t disagree. Compression does have the effect of warming the air… @jacobturner, please help me understand. :thinking:

The little electrons get closer together and get all excited at the proximity? (And a mosh pit breaks out?) :innocent:


This is the best explanation I’ve ever seen for that!

This is why superchargers in cars have their own radiator. Otherwise you’d nuke the engine with the super hot compressed air.

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When you compress a gas energy is conserved so you end up with the same thermal energy in a smaller volume and that is defined as a higher temperature.


I believe that is what I said. Thank you.

Ran the GF for about 3 hours straight yesterday, got up to about 77 degrees and no temp alert.