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Refrigerators To Cool With Sound (Cool!)

Posted by timothy on from the loud-food dept.

T-Kir writes "A very interesting report from the BBC where researchers at Penn State University are developing a prototype fridge that cools using metal plates and sound waves. If successful, this technology would help remove the dependance on gases that contribute to global warming. Talk about Cool!"

3 of 436 comments (clear)

  1. There hasn't been a DEPENDENCE on those gases... by drinkypoo · · Score: 4, Insightful
    For a long time now. We've been able to use environmentally-friendly compounds in refrigeration for some time. In addition it is currently possible to build a refrigerator with no moving parts using peltier junctions which have come down in price dramatically since they first became popular, for obvious reasons. We currently only see this technology used in mobile coolers (coolers literally, with a 12V lighter plug) and in small refrigerators for RVs which have been heavily insulated to stop loss which will require additional power use.

    But it's possible to use ANY compressable gas for cooling. The ones we use now are simply very efficient because they can store a lot of heat. There are several ways to make a cooling system more efficient (at removing heat) assuming you have not already taken the particular step to the maximum.

    1. Add insulation. This is the most obvious. More efficient insulation means less heat loss. Of course it does raise the cost of opening the refrigerator door, in comparison to the cost ratio now. This does not completely absolve you from having quick cooling because of the resulting temperature variations.
    2. Move to a gas capable of storing more heat. This one's obvious. Of course we've gone in the opposite direction to get away from Freon. Not really a great solution unless we come up with something new.
    3. Run the system at a higher pressure. Requires a more powerful compressor, which in turn requires more energy put in at this stage. Also makes the system more dangerous as it is more likely to explode and more likely to be dangerous when it explodes. On the other hand if the gas is compressed farther it will be able to accept more heat, so you should be able to get a more rapid heat transfer, especially if you...
    4. Increase the quality of your heat exchanger. Maybe it's just larger, maybe you increase its outside surface area, maybe you increase its inside surface area, maybe you just make it bigger and thus (usually) heavier.
      Of course there are two heat exchange systems in a typical refrigerator; Those inside which are intended to absorb heat, and those outside which radiate it. In a peltier-cooled system the same heat exchanger(s) do both jobs. You also end up needing some kind of heat sink to increase surface area since the thermally active portions of peltier coolers are flat.

    By using some combination of these technologies we can move away from environmentally unsafe gases. While this new technology is certainly new and may be superior in many aspects, the only reason we have not moved to more efficient and/or "eco-friendly" designs to date is expense. Welcome to capitalist terra, my friends.

    --
    "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
  2. Re:There hasn't been a DEPENDENCE on those gases.. by 5KVGhost · · Score: 5, Insightful

    By using some combination of these technologies we can move away from environmentally unsafe gases. While this new technology is certainly new and may be superior in many aspects, the only reason we have not moved to more efficient and/or "eco-friendly" designs to date is expense. Welcome to capitalist terra, my friends.

    It's not as though expense can be omitted from the equation entirely. Cheap and easily produced refrigeration technology (and air conditioning, which is closely related) have probably prevented more illnesses than any recent development since antibiotics.

  3. Get your facts straight by Phronesis · · Score: 5, Insightful
    BTW, the chlorofluorocarbons you mention are responsible for destroying ozone in the upper atmosphere, which allows more ultraviolet light through. That's a different problem, but related in the sense that now you could have sunburned, farting cows.

    CFCs and their replacements, HCFCs and HFCs, are all tremendously potent greenhouse gases. They have global warming potentials several thousand times that of carbon dioxide. The ozone problem is pretty much solved because global CFC production has dropped to near zero following the implementation of international treaties to protect the ozone layer. However, the global warming potential of HFC and HCFC replacements is worthy of concern.

    Global warming is caused by the sun.

    Just as it is true that global warming is caused by the sun, so my body generates most of the heat that keeps me warm. Nonetheless, if I wear too many sweaters, I will get too hot. Taking them off will cool me down, despite the fact that the heat is all coming from my own body. The same principle applies to the atmosphere. The earth's temperature is determined by a radiative balance. We can't change the sun, but we can change the atmosphere (our sweater), and that can cause the earth's temperature to change.