We doubt that few of us ever thought that snow globes contain real snow, but now that we’ve seen a snow globe that makes its own snow, we have to admit the water-filled holiday decorating mainstay looks a little disappointing.
Like a lot of the Christmas decorations [Sean Hodgins] has come up with over the years, this self-frosting snowman is both clever in design and cute in execution. The working end is a piece of aluminum turned down into the classic snowman configuration; the lathe-less could probably do the same thing by sticking some ball bearings together with CA glue. Adorned with 3D-printed accessories, the sculpture sits on a pedestal of Peltier coolers, stacked on top of a big CPU cooler. Flanking the as-yet underdressed snowman is a pair of big power resistors, which serve as heating elements to fill the globe with vapor. [Sean]’s liquid of choice is isopropyl alcohol, and it seems to work very well as the figurine is quickly enrobed with frost.
But wait, there’s more — as [Sean] points out, the apparatus is 90% of the way to being a cloud chamber. Maybe we’ll see a less festive version after the holidays. Until then, enjoy his ornament that prints other ornaments, his blinkenlight PCB tree-hangers, or his tiny TV that plays holiday commercials.
Ice hack!
Love the drama, science plus great electronics plus mystery.
+1 Nice tie-in to a certain movie franchise.
I tried to make a peltier cloud chamber. It’s not easy. You really need to get that temperature at minus 30 or 40 deg C.
I had one that worked with a single peltier, and a chunk of aluminium that i put in the freezer first for a few hours. This allowed me to reach the minus 45 degrees for a short time, which is cold enough.
A second attempt i did with 4 peltiers with the hot side in almost frozen brine, but i never got the cold side of those at the right temperature.
I made a stacked unit using 6 pairs of TECs sandwiched between two brass plates. On the hot side, water cooler blocks. The hot side got so hot I couldn’t remove heat fast enough.
There are flat “anti-griddle” devices which I considered pairing with my device but they also do not remove enough heat.
TECs are hard mode cloud chamber.
Let’s hope the expansion of the ice is taken into account.
It seems the vapor directly deposits as a solid, so it will not expand further.
It’s not filled with liquid if that’s the worry. It converts ambient humidity to frost. The alcohol is for something else – up to you to guess what.
This is awesome… but unless you are using the heat to warm your home, it’s also a massive waste of energy. Still, it’s impressive.
When ambient outdoor temperature is below desired household air temperature, all electronic devices operate at 100% efficiency.
So… given it’s a Christmas decoration, should be fine in the northern hemisphere.
Don’t look into the efficiency of a fridge indoors in the winter or what is passing for such right now. At some point when its cold enough a fan should be enough to chill or freeze stuff.
His intro suggests it takes minutes to work, but the video shows it working in seconds – not clear if that’s sped up. In any case, a hollow snowman would cool faster.
Since the heat is conducted through the snowman a thin wall would take longer and might not happen at all because the thermal resistance would increase over being a thicker thermal conductor. While the heat to be removed from a smaller mass of aluminum is smaller, the ability to then conduct heat from the condensing and freezing humidity would be seriously decreased – which is why heat sink bases aren’t hollow.
Great idea, I’m going to build a similar decoration, but using candle-powered absorption refrigerating (calcium chloride + water + air in low pressure, almost vacuum) or compressor one (i.e. syringe as compressor, hand or electric powered, with water or i.e. isopropanol). I started building a small absorption fridge from cans joined by epoxy glue and with valves from some old rubber belt I found outside.
Huh… I wonder if he found that snowman form somewhere or if he just pulled it out of his butt?
I think he pulled it out of his lathe.
That would have been less painful.
That could also work as a dehumidifier if there was a drain, and it cycled on & off.
Peter Fischli did a similar project as a full size snowman in 1987 and 2016. But still a tiny version is super cool.
This device has a different goal. The clue is that dosimeters are outlawed.
Some credit should be given to the original artist who fabricated this life size is 1987:
Snowman – Peter Fischli 1987
https://www.clevelandart.org/about/press/media-kit/cleveland-museum-art-unveils-life-size-snowman-sculpture