A Portable 12 VDC Water Chiller For The Chemistry Lab

Having a chiller is often essential for the chemistry laboratory, but what if you’re somewhere without easy access to water, nevermind a mains outlet to plug your usual chiller into? In that case you can build a portable one that will happily run off the 12 VDC provided by a mobile source like the accessory outlet in a car while reusing the water from its reservoir, as demonstrated by [Markus Bindhammer] in a recent video.

The build uses a compressor-based freezer as the base, which is significantly more capable than the typical Peltier-cooled refrigerators that cannot cool as fast or efficiently. The changes he made involve running in- and outlet tubing into the freezer’s compartment, with a submerged 12 VDC water pump providing the water to the outlet. This pump is controlled by a variable speed controller board that’s put in a box on the outside with the power lead also sneaking into the freezer. With these modifications in place the freezer’s functionality isn’t significantly impacted, so it can be used as normal.

After filling the compartment with water, the lid is closed and the freezer engaged. The pump controller is then switched on, with the water flow adjusted to fit the distillation job at hand. Although in this case a fairly small freezer was modified, nobody is saying that you cannot also do it with a much larger freezer, and fill it with ice cream and other treats to help it and lab critters cool down faster.

20 thoughts on “A Portable 12 VDC Water Chiller For The Chemistry Lab

  1. I never heard of roughing the threads on a nipple to ensure adherence of Teflon tape. This seems counterproductive. The peaks and valleys of the threads should trap and compress the tape to seal the joint. If they aren’t smooth they won’t fit together tightly.

      1. I can only speak for Germany. We use British Standard Whitworth. But it doesen’t matter which threads. Teflon is very slippy. It would just turn lose and would have no or very limited sealing effect. That’s the right way to do it (in Germany). At least, that’s how I learned it from scratch as a trainee.

        1. Then you learned wrong. If you wrap teflon tape WITH the thread then it will come loose when tightening. If you wrap teflon tape AGAINST the thread, it will create a tight connection.

          1. “Best practices” are not universal; they vary greatly by country.
            Anyone dealing with electrical transmission in the USA verses the EU knows the pain. I have no doubt that plumbing is just as different in appropriate procedures:
            “Becoming a certified plumber in the European Union (EU) typically involves a combination of formal education, practical training (often through apprenticeships), and potentially national-level certification processes.”

        2. I’ve teflon taped hundreds of threaded joints of different sorts. If you wrap the teflon correctly it doesn’t ‘turn loose’.

          I’ve never heard of roughing threads.

          1. You can even buy fittings with threads that have already been roughened: https://shop.ohmberger.de/viega-hahnverlaengerung-3-8-x-10-mm-448769-mod-nr-3526-rotguss-verc/
            If you have a water leak in a customer’s wall or floor and the insurance company can prove that the leak is your fault, you will have to pay for the damage yourself. And now imagine a gas pipe leaking. That’s the different between “I’ve teflon taped hundreds of threaded joints of different sorts and it worked” and a professional.

  2. Yeah,. but why bother with a fridge to do this. Much more efficient to crack apart an auto ICE makers cvhamber adn get propery cold water, rag a thermocouple to the power so once it starts to get warm, more ice forms, and stick a cycle pump to return the warmer water to the freeer part. Was thinking about doing that way for a PC cooling loop a while back

    Nice concept tho, even if it isnt’ efficient.

  3. Ever seen a portable freezer with a Stirling cryocooler in it? There s a Japanese company which makes them, and Coleman even sold one for a while. They are extremely efficient but also enormously expensive.

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