We were able to obtain this secret spy camera footage of a Glowforge employee filling the coolant tanks.
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Perhaps I should have Stated my original question much more clearly:
will my coolant freeze at 32degF???
will anything damaging happen at all below certain temperatures, if so, what?
It is now 38degF in my glowforge room. But I know you’re shipping these things and it’s sub zero outside in the shipping climate.
Your move glowforge…
Super interested in this as well. It’s cold as all heck out here- temps got down to 5 degrees yesterday. Those shipping trucks aren’t heated, and neither is my garage… I might be in trouble!
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History has shown that there is pretty much zero chance of getting info beyond the officially posted storage temperature limit. That is 40F. You might get a response that says something like, the company has not tested at temperatures outside of the official limits.
Of course the company knows that the shipping environment is harsher than the approved storage temperatures. That does not mean that I can bring it from zero to a 70F room and immediately turn it on. Just asking for trouble. That said, folks will attempt to operate or store the machine at temperatures outside of the approved range for which the unit is warranted. Presumably people more financially well off than I.
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OR… since the delivery trucks ARENT heated… and they’re still shipping glowforges… REALLY, it’s probably going to be just fine…
But until I hear more specifics, I’m trying to keep my shop above 32deg F… been hovering around 38 - 42 last few days… non heated garage. Try to keep the big door down as much as possible. (It basically gets residual heat from the house)
Really would like an official word. NOT just reading me the manual “40 is recommended for storage”… we get it. but we also realize, it’s not likely that’s the limit - nor is this DETAILED enough to tell us what actually COULD happen so that we could make decisions FOR OURSELVES… (garage is the only place I have to put this). And given that I think GF is shipping in this weather - 40 seems WAY TOO CONSERVATIVE - so I think we’re missing part of the truth here.
There’s “recommended”…
Then there is reality.
What will really happen to a GF stored, powerless, at 30. at 20. at 10. at 0. at -10…
I want to know
OBVIOUSLY, we let it warm up SLOOOOOOOWLY… and never ever power it on at those sub 60 temps… Yeah, I get that
Have a unit working it’s way across the country. Delivered to a hub in Illinois this morning when the temperature was -9F. It will be loaded for delivery to my house when it’s about zero F. Not so much worried about the delivery temps.
Figure it will take 4 to 6 hours for the coolant to warm once it’s in my house with it turned off. I put a remote temp sensor inside my current GF as a test and you would be surprised how difficult it is and how long it takes to get the inner components to a working temp once it gets cold.
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That is great info at least- I was surely gonna be excited to time my open-box-to-first-print time, but thinking about what you’ve said, I’ll be waiting overnight before firing it up!
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No. Mine was in an unheated truck at 9F and then in my garage at a similar temp for several days. It never got over 10F. When I brought it inside I left it for a day to warm up before I powered it up and it’s working fine.
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So the only remaining detail that will be useful to know…
Does the GF ship with the coolant evacuated from the laser tube, or is it fully filled in the glasstube…
I seem to remember lots of bubbles my first time turning it on, but I failed to notice if the coolant was simply evacuated until first power on or not… (Having the coolant evacuated could allow the coolant to expand safely during shipping)
Anyone letting their GF go below 32F for the winter after having used it? 
I do not believe it’s in the tube when shipped. The color of the tube changed when I powered it up.
Having the coolant evacuated could allow the coolant to expand safely during shipping
So we still have the question, what happens to the tube & coolant at sub 32F temps… I dont know that I saw an answer to that above. But the -9F temps during shipping is very interesting, we know it survives that (though the glass may not be in contact yet with any fluids)…
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This is what I meant in my other post about “self heating mode”. There is something on the order of 800W of demand when the unit is running. I think I read that somewhere. Even when running in a coldish shop (with coldish shop makeup air flowing into the unit), the unit still heats up when you use it. Presumably there is a way to make the unit draw some power without turning on the laser.
The question I had was whether the unit could be programmed (as a feature request) to draw some power automatically to heat itself in a standby mode to keep anything untoward from happening in the instances when the ambient temp drops below 40F.
For example, running the coolant pump intermittently would create heat and also keep the coolant from freezing, if in fact there is an issue with it freezing at some certain temperature.
That’s super interesting. But doesn’t the machine suck cold air in, even when idle? In a “warm” machine, I’d never run bitter cold air in there without worrying about cracking something (warm glass getting a blast of -9 F air on it… yikes). This could be the basis for their 40F minimum storage temp guideline to reduce extremes which could crack the glass - assuming GF customers have it plugged in and in idle mode 100% of the time.
Honestly, I dont understand at all who would leave the power switch on 100% of the time. Bright lights, and fans running give me 3 worries: electric bill, wear and tear on components, and noise! I always turn mine off.
Would be AWESOME to have a device I could leave inside the machine that would regulate temperature to a given setting (i.e. 45F). Without any fans sucking cold air in, this could be a solid solution! Reminds me of dog bowl heaters that you leave in an outside dog dish.
Since my GF is in a lower part of the house I can’t hear the fans at idle or see the lights. The electric use at idle is not very high. 41 watts on the Pro with the pump running. But understand why folks might want to power it down for convenience and energy efficiency.
However, as far as the wear and tear on components, the power on/off process is typically much harder on larger electronics than continuous running at idle. For a well designed piece of electronics it technically shouldn’t matter whether it’s left on or powered down. But the constant thermal change from hot to cool, hot to cool causes wear on the best of electronics, solder joints, etc. I tend to be in the camp of shutting the machine down only when it’s done for the day.
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What do you think about putting a small heating pad on top the crumbtray, always on… Attempt to maintain a ~60F temperature in there…
This one has 6 temperature settings…
My basement with the GF is cold since I only heat the upper floors with wood. Its in the mid 40s down there right now. I have a brick that sits on the edge of my wood stove all day. If I want to use the GF in the next hour I’ll turn on the furnace and lay the warm brick and a remote temperature sensor at different ends of the crumb tray with the lid closed. Once the temp sensor works it’s way up to the mid 60s, about 15 minutes, the GF is ready to turn on. BTW: the brick is probably only about 150F and gives off a slow radiant heat for quite a while.
Same way my Grandparents used to get their beds warm on a cold winter night
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Based on the number of aunts/uncles I have, I’d guess my grandparents used an alternative to the brick. 
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Love the brick method. ;-).
So what I really really want is a way to regulate the tempurature of my GF interior to minimize thermal contraction/expansion during winter, and maybe so that it is always ready to go (warmed up like your brick). It’s not a production machine for me, so I’m fine having a few weeks of downtime a year.
That’s why I was thinking about the temperature regulated heating pad above.
Now “ready to go” could only work when the outside air temp is high enough (40-60?) since you don’t want to have a blast of cold air hit the warm components inside (causing hot/cold spots, weird expand/contract… boom). But could equally run the outside air through a regulated heat box, to avoid temperature differences… probably more complicated than I want to hassle with.
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Received a new GF this afternoon. Has not yet been powered and there is definitely fluid and a few bubbles in the tube.
It was about zero at the local UPS office when it arrived, 13F in the afternoon when delivered. I quickly unwrapped it, dropped a wireless temperature sensor inside, closed the lid and put the box top back on. The sensor dropped to 32F and stayed close to that for hours. So the UPS hubs must have some heat.
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