Using The Sun To Beat The Heat

It’s practically May, and that means the sweltering heat of summer is nearly upon us. Soon you’ll be sitting outside somewhere, perhaps by a lake, or fishing from a canoe, or atop a blanket spread out on the grass at a music festival, all the while wishing you had built yourself a solar-powered personal air conditioner.

[Nords] created his from a large insulated beverage vessel. The imbibing spout offers a pre-made path to the depths of said vessel and the heart of this build, the ice water refrigerant. [Nords] fashioned a coil out of copper tubing to use as a heat exchanger and strapped it to the fan that performed best in a noise-benefit analysis.

A small USB-powered submersible pump moves the ice water up through the copper tubing. Both the pump and the fan run off of a 5V solar panel and are connected with a USB Y cable, eliminating the need for soldering. Even if you spend the summer inside, you could still find yourself uncomfortably warm. Provided you have access to ice, you could make this really cool desktop air conditioner.

[via Embedded Lab]

24 thoughts on “Using The Sun To Beat The Heat

  1. First law of thermodynamics : The “cooling” loop won’t be any colder than its surroundings. You need some other effect first to boost the heat, lose excess heat in the cooling loop then reverse to produce cold. This is how a refrigerator works. The compressor compresses the coolant from a gas to a liquid, heating it, it passes through the cooling loop, then is allowed to expand back to a gas.

  2. What a thermal ripoff. A pool of cold is with the aid of solar electric is able to cool your face. Just get out of the sun.
    Not clear on volts and watts from the article. The photo says 5watts. Maybe it gets converted to about 1amp at 5volts.

    1. Significantly better subjectively. You could drink the alcohol (mixed with a suitable mixer) and the dry ice would make fun misty stuff on the ground.

      Thermally, probably not as well because water has unusually high specific heat. They dry-ice-and-alcohol solution would give you colder air but for much less time.

      1. Mix water and alcohol, then use dry ice to create a slush. Have that slush cool another container with liquid to pump through the coil. Ultimately, you should use several coils strategically placed on the body. Then attach a small aluminum frame to a backpack and a frame that can open up above your head. One could possibly use tent poles. Mount the solar panels to the top of that. Provide yourself with shade, while cooling yourself with the the coils. Add a micro controller to this with a temperature input and possibly a PID and lcd. Dial in your coolness.

  3. A more efficient design would have the cooling loop at the bottom of the cooler, thereby effecting a thermosiphon , if the pipe were bigger, a pump perchance wouldn’t even be needed

  4. If your going to build a solar air condition there’s a much better approach. Solutions like this, using photovoltaics are never going to work very well because photovoltaics are grossly inefficient. Parabolic reflectors are much more efficient for capturing solar energy. However those generally are used to produce heat. So, how do you cool using heat? It sounds contradictory but there are in fact ways to do just that. Enter absorption refrigeration.
    http://en.wikipedia.org/wiki/Absorption_refrigerator
    Imagine a old c band satellite dish covered with a reflective material to produce a large parabolic mirror with an absorption refrigeration system located at the focal point. You could then use photovoltaics to power a tracking system using a microcontroller to drive actuators to track the sun.

  5. Idea/demo needs expansion to several applications. Bring Good Things to a Less-Affluent World, and for the first time ever, actually allow non-affluent to exist merely, a lifestyle defined in part by energy available (via miracle under-applied, photoelectric technology) from the sun. (I’ve been thinking to use glycol, circulated from 8-inch schedule-40 in my sofit, to a super-insulated chamber on my counter top. I guess it might require about 75-watts per day for circulation.) Kickstart this project. Products could exist in several forms. My sketches and such, all exist as prior art BTW. Eh? Less-Affluent? Solar Lifestyle? Charge-up you GEM car? Eh? This refrigeration will work nearly 7 months of year, other 5 I can rely on a compressor type and higher solar input. Sure beats getting a perpetuating bill in my mailbox… Eh? Solar Lifestyle?

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