I want to freeze water as quickly as possible. Let me explain my situation :

I have a setup that holds water which needs to freeze to create a surface of ice on which I will be demonstrating products.

I have a compressor with a pump that runs Glycol in some copper pipes immersed in the water.

This whole setup is great and transportable, but it takes an eternity to freeze around 10L of water (more than 6 hours) and I need it to be faster than that since I will be traveling with it to give demonstrations!!

I am looking for a way of accelerating the freezing process, ideally without having to change the whole setup (I am willing to change a couple of parts or whatnots).

  • Can you provide a diagram or picture of your set-up?
    – Stan
    Commented Oct 25, 2017 at 20:45
  • <comment removed> @Stan No need to pre-qualify your answer. If you have an answer, please post it below, thanks. Commented Oct 25, 2017 at 21:02
  • 1
    Can you use a different refrigerant with your present equipment such as monomethyldichloroethane instead of just glycol. @RobertCartaino This was not my answer - It might not be possible with the person's compressor due to safety concerns as it is toxic. Bob, My answer is submitted conventionally as an answer.
    – Stan
    Commented Oct 25, 2017 at 21:14
  • Please let us know how it turns out.
    – Stan
    Commented Oct 31, 2017 at 14:37
  • Why not transport the slab of ice to the destination? (unless you travel by plane...)
    – bobflux
    Commented Nov 25, 2017 at 17:04

6 Answers 6


Try to ditch commen sense and go for science!

1. Use hot water as your starting point.

Exploit the Mpemba-effect:

enter image description here

Since there is some debate about the effect, whether it is real or not: the greater the exposed surface area, like in a lake were the effect was discovered or the apparent application from the question, the stronger the effect seems to be.

If you keep accurate records about this you may contribute to the exact sciences as well.

2. Use de-salinated water, and then add back in impurities, like testosterone

Salt water has a lower freezing point. We want to avoid that. Using really pure water may be less than ideal, but adding a small amount of impurities back in actually raises the freezing temperature. And surprisingly to be as cool as ice but actually a bit hotter the water may benefit from a bit of testorerone.

3. Use a long chain alcohol as a crystal-forming primer

Drunk water, like drunk people, freezes easier.

Starting above 4 chain carbon molecules, pentanol and above, added in very small amounts may accelerate the ice crystal forming process. The glycol mentioned in the question is known as an anti-freeze, because it is so short. Longer molecules may reverse this effect.

These options are not in any special order.


Try starting with a cooler solution when you arrive at your destination and set up for your demonstration.

Rather than filling your tray (tank) with plain tap water, stop at a convenience store to get crushed ice and add the minimum amount of water to the ice chips to make a slush. If you have a mallet, you can reduce cubes to chips in a few minutes right in the plastic bag used to carry them. A nylon bag is reusable and much neater to use to hold cubes while you pulverize them with the mallet.

Motels and hotels have ice machines on every floor. Many supermarkets have machines that make crushed ice in bulk. You don't need more than a few kilograms to get a head start on the process.

Then, all you must do is pull the temperature lower is start the compressor to finish the job.

Good luck.

  • Motels and hotels have ice machines on every floor: in the US, perhaps. Not so common in NW Europe, for instance.
    – Hobbes
    Commented Oct 26, 2017 at 8:58
  • Thanks that is an interesting idea! I am in Canada, we have those vending machine in hotels/motels and convenience stores as well. I like the idea of adding ice to the water to it freezes water more quickly! Commented Oct 26, 2017 at 12:43
  • @PascalCadorette First add all the ice-as much as you can get. Add the water to the ice chips so that it will have more ice than water to be even colder
    – Stan
    Commented Oct 26, 2017 at 14:43

I don't know how big your surface of ice must be, but maybe something like the following could work for you.

Travel with some blocks of dry ice in a cooler. At presentation time, lay the blocks out and put a metal (aluminum should work well) plate on top. After the plate is very cold, pour a small amount of water across the plate to create a thin sheet of ice.

  • Or perhaps drop the dry ice directly into the water.
    – Lawrence
    Commented Nov 3, 2017 at 23:25

You could use chemical reactions which are endothermic (they suck heat out of stuff). This will work assuming your product isn't food based. You could use bottled water which freezes faster that tap water. You could put a portable fridge in the back of your car to freeze water while driving around.

Hope I helped :)

Edit: here is a video of an endothermic reaction I think you could use:endothermic reaction

  • 1
    It would be a better answer if you could suggest some easy endothermic reactions that can be used.
    – Chenmunka
    Commented Nov 1, 2017 at 12:23
  • Practically all North American bottled water IS tap water. (Lookin' at you Nestlé.)
    – Stan
    Commented Nov 1, 2017 at 13:53

I suppose you need a smooth ice surface for your product. The key is to have a small temperature difference so the freezing process goes as fast as possible.

  1. Do not fill your container fully and prefreeze it before starting. Build an isolation chamber either with industrial foam in a form or (easy and cheap) wrap the container into lots and lots of newspaper pages.
    Also get a jug of water and place it into the freezer so that ice is building, meaning the water is near 0°C. Put that water into a thermos.
    So you have now an almost full container of ice and a thermos of very cold water.

  2. When you need it, get the container out. Most of the ice should be still there. Place some weights on the ice so it does not float and carefully pour the thermos water on the ice so that the container has the level you need.

  3. Switch the cooler on. Now the thermos water is still cold and it gets cooled by the ice underneath it. The freezing process should now go very fast.


In terms of physics, hot water freezes faster than cold water, so take that into consideration!

  • I assume you're talking about nucleation. The difference for tap water would be negligible.
    – Chenmunka
    Commented Nov 14, 2017 at 9:39

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