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HEg heat exchange girdle (hr)

ALH_4 Member Posts: 1,790
I wonder if that setup would dump the heat from the solar panels quickly enough to cycle the tank between its minimum and maximum temperatures diurnally? Also it seems the heat loss off the outside of the unit would be harder to control than with an immersed heat exchanger. With an immersed hx, the heat need only pass through one layer of metal. With this setup it has to pass through three layers that are not in perfect contact. If it's an atmospheric tank, I would just drop a coil of copper inside.



  • hr
    hr Member Posts: 6,106
    Turn any tank into a hx tank

    I built this with a bunch of aluminum transfer plates pop rivited together. Segments can be added or subtracted to fit different diameter tanks. A spring pulls it tightly against the tank.

    Either PAP or Onix will be used to gather the ends.

    This could be wrapped around pretty much any tank or vessel.

    Even an old hippie living in a trailer down by the river could build a solar HX with an old 55 gallon barrel :)

    hot rod

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  • Paul Pollets
    Paul Pollets Member Posts: 3,428

    What about a dielectric reaction between the aluminum and the steel tank?

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  • Brad White_75
    Brad White_75 Member Posts: 15
    Only in the presence of an

    electrolyte (including water) will corrosion occur. Condensation from the air would do it but once dry it will stop. Water completes the circuit essentially, the round trip between the metals. Add any impurities such as salt and it speeds up. HR's hands never sweat :)
  • J.C.A._3
    J.C.A._3 Member Posts: 2,981
    Thinking outside the realm....

    Why not? It could work in either direction, if applied properly...

    HR, did you get the email I sent over the weekend? (jetbug) Chris
  • hr
    hr Member Posts: 6,106
    I did get the bug link

    thanks! I'm watching e-bay for it to go up for sale. Figure I could use it to thaw frozen slabs :)

    hot rod

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  • Plumdog_2
    Plumdog_2 Member Posts: 873
    Who you callin an old hippie?

    I represent that remark. You could leave them flat, paint it black and mount it on top of your trailer for collectors.
  • hr
    hr Member Posts: 6,106
    Good points Andrew

    this is mainly for sealed pressurized tanks. Rheem/ Ruud has been making an external HX Solaraid tank for years. I think 100 feet of 5/8" copper wrapped around it. I'm trying to provide a retro fit external that would fit nearly any any.

    I have been coming across a lot of tanks in my area, but none with HXers, mostly stainless stuff from the large food manufacturing industry in our area. Also ASME pressure rated LP tanks of various size. Nice for wood burning boilers and large solar storage capacity.

    I agree the coil in the tank would be prefered. As would two pumped flows to increase transfer.

    hot rod

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  • ALH_4
    ALH_4 Member Posts: 1,790

    Would it work better than the "solar wand" exchangers? I have no experience with the wands, but the surface area and pipe diameter is small from what I can tell. I guess it depends on the use and whether you have an extra threaded port available. Could you copy what Rheem is doing but use lots of pex-al-pex instead of copper to keep the cost down? Although no matter what you use to wrap the tank it will expand some and greatly decrease the contact surface area.

    Economical energy storage is not an easy problem to solve. From what I understand at this point, the best options seem to be to use an indirect water heater for SDHW or a non-pressurized tank with multiple hx's for space heating storage. Heat exchanger performance is so incredibly important to the ROI in solar applications. A solar loop that cannot get rid of its heat could be a real problem. Hope Google doesnt put a bunch of laxative ads on this thread now. ;-)

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