Solar water heating

Discussion in 'Solar and Geothermal Water Heating Forum' started by molo, Jul 6, 2007.

  1. molo

    molo Member

    Messages:
    854
    Location:
    cold new york
  2. Rancher

    Rancher Guest

    I've used a couple of kinds of solar hot water heaters over the past 25 years, what's the question.

    That's currently how I provide my hydronic floor heat.

    Rancher
  3. Pewterpower

    Pewterpower New Member

    Messages:
    262
    Location:
    Tampa
    I love mine. I have two huge panels on the roof and a 120 gal tank. It has an elect backup, but in 10 yrs I don't believe that it has ever been needed nor have I ever run out of hot water. The only time the water has ever been slow to heat was on the 4th cloudy day in a row. Luckily, I'm in FLA so the sun is intense and that doesn't happen that often.
  4. Mikey

    Mikey Aspiring Old Fart, EE, computer & networking geek

    Messages:
    2,736
    Location:
    Central Florida
    Works great in FL

    I have a single collector and an 80 gallon tank. The house and surrounding trees aren't positioned well for solar, so I was hopeful but not overly optimistic. It was first installed in November, as I remember, for about $3K after tax credits and incentives. During the installation and testing, somehow we neglected to turn the power back on, and it ran for a month or so without electricity. After a few days of cloudy weather, showers got a little tepid, so I checked things and turned the power back on, but I doubt it's being used much.

    I'd like to make the collector adjustable for the varying elevation of the sun, and provide for "docking" the thing during hurricanes, but that's a ways down my list right now.
  5. Pewterpower

    Pewterpower New Member

    Messages:
    262
    Location:
    Tampa
    The hurricanes have always worried me, too. But in 10 yrs that we've had the panels, we haven't seen a hurricane. Several Tropical storms, though. But no damage at all. Those things are anchored to the roof pretty damn good.
    Btw, how did it work so long with no power? Don't you need power to run the recirc pump?
  6. got_nailed

    got_nailed DIY Senior Member

    Messages:
    277
    I have 2 closed loop 50 gallon tanks. I use them as pre heat tanks. They feed a 30 gallon hot water heater. During the winter it’s to cold out side for them to work so I feed water in off my wood boiler.

    I bet he didn’t turn the power on to his hot water heater. But because he was testing the system the pump was on.
  7. molo

    molo Member

    Messages:
    854
    Location:
    cold new york
    I'm in a cold climate (new york state), but we get 3 months of warm weather, and them some occasional warm weather for may and september. Look at this roof, it faces south and gets HOT!. I would like to set something up, anything, to collect this heat. I don't want to spend much, and can build, or have built, components if I need to.

    Any Ideas?

    Thanks for the input
    Molo

    Attached Files:

  8. Pewterpower

    Pewterpower New Member

    Messages:
    262
    Location:
    Tampa
    Oh, he meant the the power for the electric backup. Gotcha. ;)
    As far as a cold climate goes, I can't help you much....... but I do know that frozen water is the last thing in the world that you want in a solar collector. As the water expands into ice, it will tear it to shreds. But they do have a relief valve that prevents it from freezing by blowing out water, thereby keeping it moving (and warm). I remember the first time mine did that, I was freaking cuz I had water pouring off my roof... :D
  9. got_nailed

    got_nailed DIY Senior Member

    Messages:
    277
    Milo
    Your cost to pay back is not worth it for you. Save your money.
  10. passive solar panels---air type

    I have already posted this once somewhere else.


    just build some solar panels that move air through them.

    set up a thermostatic fan and get the heat

    to heat the home..

    either on the roof or on the south side of the house

    read this old link


    http://www.terrylove.com/forums/showthread.php?t=12841
    Last edited: Jul 8, 2007
  11. Mikey

    Mikey Aspiring Old Fart, EE, computer & networking geek

    Messages:
    2,736
    Location:
    Central Florida
    It's pure solar

    Circulation pump is also solar powered by a small PV array. It's kind of elegant in terms of a control system -- water circulates only if there's enough light, which I guess implies heat as well -- but the engineer in me is dying to instrument the hell out of it to see just what's going on.
  12. kelvinwong

    kelvinwong top 1 Solar in China

    Messages:
    3
    Location:
    Jiangsu Province, China
    They are solar hot water heating systems. And I think collector of evacuated tubes with heat pipe in is better than flat plate collectors, for they are no water in the collector no fear of freeze. and evacuated tube collectors is of high efficiency.

    For cold areas, you will need heat exchanger(usually copper coils in the tank) for heating exchanger. Before using, you should filling anti freeize into the pipeline. And that is called indirect circulation system.
  13. Alphacarina

    Alphacarina New Member

    Messages:
    26
    Location:
    Biloxi, MS
    Lots of ideas

    You don't need 'warm weather' to make hot water - You just need lots of sunshine. My system makes lots of really HOT water even on 40 degree days . . . . so long as the sun is shining, and where I live, it usually is

    If the system components were all 'home made' it would probably make 75% less than it does, because nothing beats a high tech collector and a well insulated storage tank - I spent about $2500 on components . . . . and the government immediately paid me back about 1/3rd of that on my first year's income taxes. My system has been up and running now for 4 years and since it provides more than 90% of my family's hot water needs year 'round, I'm getting really near the 'paid for' point so it will all be gravy now for the next several years

    I spent right at $1K for my single 4 by 10 foot AET panel, another $600 for my two Sears PowerMiser 12 water heaters/storage tanks and then another several hundred for differential controllers, pumps, valves, copper tubing and insulation - I installed everything myself

    We'd all like 'something for nothing' I guess, but there are areas where you really do get what you pay for and solar water heating is one of them. I suppose you could spend a few hundred dollars for something which might meet 10 or 15% of your family's needs . . . . and your home-made system might last you a year or two . . . . maybe more assuming nothing freezes and the wind doesn't blow it away, but I would advise you either plan on spending whatever it takes to do it properly . . . . or treat your efforts as an entertainment/learning experience - Which will likely have you spending the $$$ to do it correctly at some point in the near future

    Don
    Last edited: Jan 11, 2011
  14. Mikey

    Mikey Aspiring Old Fart, EE, computer & networking geek

    Messages:
    2,736
    Location:
    Central Florida
    Don, how did you protect the collector from freezing? I'm assuming you're circulating water through it, based on the storage tank(s) you used. I'd also be interested in more detail on your controller -- I've just got a PV array that drives the circulating pump -- simple, elegant, and totally unsatisfying to a retired engineer. I need some knobs, dials, gauges, etc.

    Update -- I'm a little enlightened by your post on the drainback thread, but am still interested in the control system.
    Last edited: Jan 11, 2011
  15. rogerd

    rogerd New Member

    Messages:
    8
    Location:
    India
    You don't need hot weather to get hot water. It is the light in the sunlight that is converted to electricity. When the light hits the panels it is converted to tiny amounts of electricity. So, even if you have cold but sunny days you can get really hot water.
  16. Mikey

    Mikey Aspiring Old Fart, EE, computer & networking geek

    Messages:
    2,736
    Location:
    Central Florida
    That's not how mine works, but the last sentence is true. I get 170° water on 30° days.
  17. paloma

    paloma New Member

    Messages:
    1
    Location:
    India
    Solar Energy is a sunlight that converts in electricity. But we have check whether volt is high while using the solar energy. In winter day how we get a hot water.
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