Page 1 of 2 12 LastLast
Results 1 to 20 of 23

Thread: Homemade solar water system

  1. #1
    Junior Member
    Join Date
    Feb 2008
    Age
    40
    Posts
    154
    Thanks
    0
    Thanked 1 Time in 1 Post
    Rep Power
    144
    Reputation
    17

    Default Homemade solar water system

    Anyone successful made a homemade solar water system?



Look Here ->
  • #2
    Junior Member
    Join Date
    Feb 2008
    Age
    40
    Posts
    154
    Thanks
    0
    Thanked 1 Time in 1 Post
    Rep Power
    144
    Reputation
    17

    Default

    The rough design in my head is as follows:

    - Wooden box with glass on the front.
    - Box is insulated with foam or some sort of insulation
    - reflective surface at the back of the box
    - copper pipes in the air space (painted mat black)
    - insulated pipes to and from the tank
    - an old hot water tank

    Thermal Siphoning Setup (the water circulates itself around)

    - tank needs to be above the solar panel
    - cannot be used in areas that drop below freezing

    Pumped Setup

    - an electric pump circulates the water, so a power source is required
    - a microcontroller would check the temperature of the panel. If it's above a certain temperature then it will circulate (protects the copper pipes when in freezing temperatures, stops the panel acting as a cooling device and stops the pump at night).

    - the temperature of the hot water in the tank is also checked and if above a certain amount the pump will stop also to prevent over heating. Temperatures of 90 degrees C are possible in hotter climates. 50 degrees C would probably be all that's required.

  • #3
    Member
    Join Date
    Jan 2008
    Posts
    257
    Thanks
    18
    Thanked 11 Times in 6 Posts
    Rep Power
    149
    Reputation
    62

    Default

    You've got a pretty good handle on it. I haven't seen any with reflective backing under the pipes. If it's all painted matt black it's gunna absorb the energy from the sun better and keep it captured inside your little hothouse, heating the water more efficiently. The newer ones also have the front glass diffused a bit as well. Not sure why they do it. I know in my job of installing skylights, the opal domes on the tubelights work far better than the clear domes do. The diffused light seems to throw further and more evenly around the room. Maybe I've answered my own question?

  • #4
    Junior Member
    Join Date
    Feb 2008
    Age
    40
    Posts
    154
    Thanks
    0
    Thanked 1 Time in 1 Post
    Rep Power
    144
    Reputation
    17

    Default

    yeah the reflective backing is my own assumption based on various articles and experiments. I have seen one that has a copper back plate painted black which was effective. But I've also read that reflecting the light back onto a different surface of the tubes gives an extra heat increase. Might be worth trying both. I've read that attaching the backing plate to the pipes works well when it's hot but when the sun goes out a bit it acts too much as a cooling device.

    Interesting what you say about the diffused light, sounds plausible to me too.

  • #5
    Senior Member
    Join Date
    Jan 2008
    Posts
    708
    Thanks
    78
    Thanked 121 Times in 75 Posts
    Rep Power
    174
    Reputation
    575

    Default

    http://cgi.ebay.com.au/Solar-Hot-Water-300Ltr-Collector-30-Tube_W0QQitemZ120360172651QQcmdZViewItemQQptZAU_Ho me_Appliances?hash=item120360172651&_trksid=p3286. c0.m14&_trkparms=66%3A2|65%3A1|39%3A1|240%3A1318

    In the long run might be cheaper to buy

  • #6
    Junior Member
    Join Date
    Feb 2008
    Age
    40
    Posts
    154
    Thanks
    0
    Thanked 1 Time in 1 Post
    Rep Power
    144
    Reputation
    17

    Default

    Those systems are excellent, freeze proof, sealed and apparently out perform the standard setup of piping the water through the heating tubes. I just wonder would they get smashed with hail?

  • #7
    Senior Member
    weirdo's Avatar
    Join Date
    Jan 2008
    Posts
    5,458
    Thanks
    4,638
    Thanked 3,134 Times in 1,632 Posts
    Rep Power
    0
    Reputation
    29582

    Default

    Would polypipe be a better alternative to copper? In regards to long term fatigue maybe? (expansion and contraction)
    It's black already which would save having to paint it. You would have to make sure it's UV stable.
    If you use polycarbonate as a cover it would be pretty hailproof. (same shit coke bottles are made of)
    You can even get this stuff in core flute material

  • #8
    Member rickove's Avatar
    Join Date
    Jan 2008
    Location
    Mount Gambier S.A.
    Posts
    261
    Thanks
    5
    Thanked 3 Times in 3 Posts
    Rep Power
    148
    Reputation
    35

    Default

    a couple of setups Ive of seen of solar pool heater kits seem to use the blackirrigation polypipe an they work ok?a kit recently in bunnings stores was similar tho pricey$$.

  • #9
    Member
    Join Date
    Jan 2008
    Posts
    257
    Thanks
    18
    Thanked 11 Times in 6 Posts
    Rep Power
    149
    Reputation
    62

    Default

    poly doesn't have the heat conductivity as that of copper. You'll notice that pool heating covers a whole side of the roof, just to get a couple of extra degrees. Poly pool heaters would work better if they were enclosed but it's a bit impractical.
    I was gunna make a pool heater out of an old solar panel but the chlorine would have reacted with the copper too much.

  • #10
    Senior Member Mods's Avatar
    Join Date
    Jan 2008
    Age
    51
    Posts
    595
    Thanks
    260
    Thanked 261 Times in 132 Posts
    Rep Power
    205
    Reputation
    2305

    Default

    Quote Originally Posted by weirdo View Post
    If you use polycarbonate as a cover it would be pretty hailproof. (same shit coke bottles are made of)
    You can even get this stuff in core flute material
    Not sure that's correct, as I know it polycarbonate, and polyethelene are very different materials. Polycarb is extensively used as roof covering and for bulletproof materials (due to it's softness), polyethylene is more widely known for its use in plastic shopping bags (and coca cola bottles ).
    However both would probably serve the purpose in this instance - however they are different.

    Cheers.
    When I was a kid, I used to have an imaginary friend. I thought he went everywhere with me. I could talk to him and he could hear me, and he could grant me wishes and stuff too. But then I grew up, and stopped going to church.

  • #11
    Senior Member
    weirdo's Avatar
    Join Date
    Jan 2008
    Posts
    5,458
    Thanks
    4,638
    Thanked 3,134 Times in 1,632 Posts
    Rep Power
    0
    Reputation
    29582

    Default

    Quote Originally Posted by Mods View Post
    Not sure that's correct, as I know it polycarbonate, and polyethelene are very different materials. Polycarb is extensively used as roof covering and for bulletproof materials (due to it's softness), polyethylene is more widely known for its use in plastic shopping bags (and coca cola bottles ).
    However both would probably serve the purpose in this instance - however they are different.

    Cheers.
    Coca cola bottles are definitely made from poly carbonate.
    Poly ethylene is a softer plastic.

  • #12
    Member
    Join Date
    Jan 2008
    Posts
    257
    Thanks
    18
    Thanked 11 Times in 6 Posts
    Rep Power
    149
    Reputation
    62

    Default

    even so, the coreflute stuff acts as an insulator. It has two layers separated by an air gap. You would loose performance. I have seen the coreflute panel itself being used as a solar panel.

  • #13
    Senior Member Mods's Avatar
    Join Date
    Jan 2008
    Age
    51
    Posts
    595
    Thanks
    260
    Thanked 261 Times in 132 Posts
    Rep Power
    205
    Reputation
    2305

    Default

    Quote Originally Posted by weirdo View Post
    Coca cola bottles are definitely made from poly carbonate.
    Poly ethylene is a softer plastic.
    Some (like water cooler bottles), but every containter which is labeled with 'PET' - surprisingly is an acronym for Polyethelene
    A quick google of the two plastics will steer you on the right track If you cbf'd doing that then maybe peruse these links




    I did a bit more googling - it seems that cc use p/carb on 5l and above re-usable drinking containers, and PET on all the stuff below (500ml/1.25ml/2l/etc..)
    Anyway, OT - enough said.


    Cheers.
    When I was a kid, I used to have an imaginary friend. I thought he went everywhere with me. I could talk to him and he could hear me, and he could grant me wishes and stuff too. But then I grew up, and stopped going to church.

  • #14
    Senior Member
    weirdo's Avatar
    Join Date
    Jan 2008
    Posts
    5,458
    Thanks
    4,638
    Thanked 3,134 Times in 1,632 Posts
    Rep Power
    0
    Reputation
    29582

    Default

    I stand corrected Mods

  • #15
    Premium Member
    oceanboy's Avatar
    Join Date
    Jan 2008
    Posts
    16,166
    Thanks
    7,277
    Thanked 8,786 Times in 4,486 Posts
    Rep Power
    3693
    Reputation
    150792

    Default

    You stand erected weirdo!

  • #16
    Banned
    watchdog's Avatar
    Join Date
    Jan 2008
    Posts
    2,966
    Thanks
    136
    Thanked 869 Times in 514 Posts
    Rep Power
    0
    Reputation
    8320

    Default

    Poly pipe is perfect if it is gravity feed. If it is pressure fed the poly will soften & rupture.

  • #17
    Member
    Join Date
    Jan 2008
    Posts
    257
    Thanks
    18
    Thanked 11 Times in 6 Posts
    Rep Power
    149
    Reputation
    62

    Default

    Quote Originally Posted by watchdog View Post
    Poly pipe is perfect if it is gravity feed. If it is pressure fed the poly will soften & rupture.
    There is, of course, high pressure poly. It's got a blue stripe along it's length.

  • #18
    Banned
    watchdog's Avatar
    Join Date
    Jan 2008
    Posts
    2,966
    Thanks
    136
    Thanked 869 Times in 514 Posts
    Rep Power
    0
    Reputation
    8320

    Cool

    Quote Originally Posted by jmc96 View Post
    There is, of course, high pressure poly. It's got a blue stripe along it's length.
    And it is usually buried so not exposed to high temperature or have to carry hot water under pressure. I have been down this path. Its not nice to come home & find the hose has rupured & you've been watering your roof all day.

  • #19
    Member
    Join Date
    Jan 2008
    Posts
    257
    Thanks
    18
    Thanked 11 Times in 6 Posts
    Rep Power
    149
    Reputation
    62

    Default

    fair enough, I'll raise a drink to that.

  • #20
    Junior Member
    Join Date
    Feb 2008
    Age
    40
    Posts
    154
    Thanks
    0
    Thanked 1 Time in 1 Post
    Rep Power
    144
    Reputation
    17

    Default

    Poly pipe would probably heat it sufficiently in north QLD but I'm not willing to spend money to test it. I've heard tales of black poly pipe running the perimeter of a fence and thermosyphoning enough hot water for a house but I have doubts about that setup.

  • Page 1 of 2 12 LastLast

    Bookmarks

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •