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  • transporting heat - conduction/radiation

    I'm a designer and have a technical design for cleanrooms in hospitals. My big issue is how to transport heat from an insulated product to the hospital room. The big thing in this design is how to do this but without make air move within the system (the vacuum pump is already responsible for a small air displacement). the only thing I can imagine is put the cover of the box full of peltier elements but that's quite unlikely to happen... who knows a good solution?
    dimensions of the box are 0,5m x 0,5m x 1,3m and the volume of air is 0,325m³.
    you can view a small scheme on http://users.telenet.be/dennonnenmolen/schemawarmte.pdf

    tnx!

  • #2
    Re: transporting heat - conduction/radiation

    Woody, I'm not going to BS you. I have no idea what you're talking about. But; is this a unique application to only you? I've found when I run into a problem such as this, there's something already invented for the application. Perhaps you need to talk to another hospital, take a tour of their facilty and see what they do. I am interested though, what's this entire thing for?
    Buy cheap, buy twice.

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    • #3
      Re: transporting heat - conduction/radiation

      Oh come on Gear you probably have one of these things in your garage right now.

      Why does the airlock open for 1 sec every 5 mins?

      Comment


      • #4
        Re: transporting heat - conduction/radiation

        Originally posted by woody1983 View Post
        I'm a designer and have a technical design for cleanrooms in hospitals. My big issue is how to transport heat from an insulated product to the hospital room. The big thing in this design is how to do this but without make air move within the system (the vacuum pump is already responsible for a small air displacement). the only thing I can imagine is put the cover of the box full of peltier elements but that's quite unlikely to happen... who knows a good solution?
        dimensions of the box are 0,5m x 0,5m x 1,3m and the volume of air is 0,325m³.
        you can view a small scheme on http://users.telenet.be/dennonnenmolen/schemawarmte.pdf

        tnx!
        "My big issue is how to transport heat from an insulated product to the hospital room. "

        Either the wording is off or I'm misinterpretting it...take the insulation off.

        Comment


        • #5
          Re: transporting heat - conduction/radiation

          Two words; heat pipes
          ---------------
          Light is faster than sound. That's why some people seem really bright until you hear them speak.
          ---------------
          “If I had my life to live over again, I'd be a plumber.” - Albert Einstein
          ---------
          "Its a table saw.... Do you know where your fingers are?"
          ---------
          sigpic http://www.helmetstohardhats.com/

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          • #6
            Re: transporting heat - conduction/radiation

            Bob, can you add more words? You lost me.
            Buy cheap, buy twice.

            Comment


            • #7
              Re: transporting heat - conduction/radiation

              Originally posted by gear junkie View Post
              Bob, can you add more words? You lost me.
              I think he means fluid convection...kinda like a hot water boiler works.

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              • #8
                Re: transporting heat - conduction/radiation

                Nope. A heat pipe is a passive transfer mechanism. Basically you can create one with a piece of copper pipe and a couple caps, some glycol solution as the transfer medium, and a vacuum pump.

                Braze a cap on each end. You 'll also need a schreader valve or some other port you can draw a vacuum through and do a vacuum fill and braze that in the top cap.

                Now you need to draw as low a vacuum as you can then partially vacuum fill the tube to about 33% full of glycol.

                Take a piece of insulation board and bore a hole through it at about a 45 degree angle from vertical that the pipe will fit into snugly.

                Place one side toward the sun and the other side in the shade of the insulation board.

                The sun should heat the glycol to its reduced boiling point (since its in a vacuum it will boil at a lower temp right). The vapor travels up the pipe to the high side which is one the other side of the insulation board. There it gives up its heat to the copper pipe which radiates it into the room (or what have you). When the BTUs are gone the vapor condenses and runs back to the 'cold' side where it is re-heated by the sun or some other heat source.

                Now imagine a whole wall of hundreds of these. The heat is not conducted back out of the building because the inside half of the tube is filled with vapor which does not conduct as readily.

                This was in Popular Science over 30 years ago. They tested whole panels filled with dozens of these "Heat Pipes". The were put in frames the size of std window rough-in openings. The outside had dark glass so you could not see the heat pipes, just looked like shaded glass from the street. The inside was louvered to allow the heat to escape into the room. They were about 45% efficient but since there were zero moving parts and literally no energy expended for what output was received they worked great. No fuel to buy, no maintenance, no parts to replace.

                I think the patent got bought up by the oil companies or someone else big. I never heard anything about them again. I had the copy of Pop Sci for many years, but I lost it over 20 years ago somewhere. I wrote a letter to Pop Sci back in the early 90s asking about what became of it but no one there remember anything about them.

                You might think I am dreaming this all up but I heard that the oil companies used something like this on the Alaskian Pipeline from a friend of mine who worked on it for over two years. He said they used them on the pipe supports across the tundra to keep the heat from from the pipe being conducted into the ground and melting the permafrost around the supports.

                That's why I say somebody holds the patent and has it tucked away in a file drawer somewhere.
                ---------------
                Light is faster than sound. That's why some people seem really bright until you hear them speak.
                ---------------
                “If I had my life to live over again, I'd be a plumber.” - Albert Einstein
                ---------
                "Its a table saw.... Do you know where your fingers are?"
                ---------
                sigpic http://www.helmetstohardhats.com/

                Comment


                • #9
                  Re: transporting heat - conduction/radiation

                  could you use refrigerant? I've never heard of this, very interesting. This sounds similar to Michael Faraday's discovery of air conditioning.
                  Buy cheap, buy twice.

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