Homemade cooler for Glowforge

With the summer heat and a non-airconditioned studio, I’ve found times when I couldn’t print. I found this useful design for a homemade A/C unit on Instructables.

Styrofoam or plastic cooler
4" +/- tube for exhaust
Frozen water bottles
Tool to cut holes in cooler


  1. Cut a hole in the top of the cooler for your fan to sit on. It will blow air into the cooler.

  2. Cut a hole in one of the sides of the cooler for the exhause tube.

  3. Fit tube in hole.

  4. Fill cooler with frozen water bottles.

  5. Position cooler so exhaust tube points to the right front corner of the GF (this is where the air intake is).

  6. Put fan face down on the hole in the top of the cooler.

  7. Turn it on.

VOILA, you’re done.


Seems like condensation would be a concern.
Seeing any beads developing?

If was happening, I suppose it would show on the bottom edge or the glass lid. Wherever the air was trying to become ambient again.


The condensation happens in the cooler. Water condenses on the outside of the frozen bottles, so every now and then the cooler has to be drained or wiped dry.

I started out re-using using 16 oz water bottles to put in the cooler but they thaw pretty quickly. Now I’m freezing water in gallon milk jugs and they keep working for quite a while. This afternoon I worked for a couple of hours and when I was finished and put the bottled back in the freezer there was still a lot of ice in them.


i think the concern would be that you’re blowing cool, moist air into a warmer environment. that could create condensation inside the warmer environment.

Hum, I think you have that backwards. You get condensation on objects that are colder than the surrounding air.


altogether possible i’m wrong with the condensation. but you’re still potentially blowing moist air into the GF.

We have too many creative solutions to heat issues. This works but why do we have to do it.

Very clever. Good job and thanks for sharing

There was a sign in a metal fab shop I used to work in that listed options for customers to choose for their desired results on jobs they brought to us. It instructed them to “pick any two,” and the options were 1. Fast 2. Cheap and 3. Good. Pretty much applies to everything in life.


The ambient air is quite humid, which is why it condenses on the frozen bottles in the cooler. The cooled air that is blowing towards the GF is dryer than the ambient air. I haven’t noticed ANY condensation inside the GF.

I hadn’t looked for other solutions to the cooling issue, but I will. I’m interested to see what others have done. This Instructable just seem to come along at the right time for me.


If you do some googling around you can find some studies that will show the decrease in efficiency as temps increase (and also as they get too cold).

That’s kind of the answer to your question as it was posed. You could run outside of those thermal protection levels, but you’re going to have inconsistent results, decrease the life of your tube, etc.

But, I think your question may have been more about why the cooling system wasn’t designed more robustly?

We can only speculate there. I see this as an all-in-one, plug and play solution that doesn’t have buckets of ice water with algae growing in them. Having that as a cooling solution wasn’t very attractive to me. Neither was having a CW5200. I can only imagine the trouble tickets that would come in from a Glowforge plugged in, with a big chiller, then the filter and the subsequent tripped breakers.

As it is, Glowforge doesn’t fall too far below most other laser cutting units (for the pro at least - the basic is a bit different and unique). And people that run them in very rough environments are usually exceeding the manufacturers recommendations as far as the delta between ambient air temp and coolant temp. The difference being nothing is stopping them from doing so.


With a block of dry ice in the cooler you might not need the fan, and you get the bonus of retarding any flames! :smile:


I’ve wondered how well the clay pot evaporative cooler solutions would work. I understand the resultant humidity in some places might not be desirable, but it would give you cooler air.


Someone told me yesterday that he used a small refrigerator the same way as the cooler. Obviously, it has the advantage that the ice doesn’t melt. He said the holes went through the door, where there is nothing you might accidently damage by cutting.