Solar Hot Water controller

RobPattonDotComRobPattonDotCom Registered Users Posts: 11
Hopefully this is an ok place for this topic.

I'm wondering if anyone has started/built/thought about a pic based solar hot water differential controller. Using a basic stamp or something.

I've got a Goldline GL30, which I'm sure does a fine job, but.

1. I have no way to gather data or show its real activity.
2. Its a hastle to adjust, and its less than accurate.
3. It just lacks the cool factor of something built, with an LCD screen.

Surely this is simple enuf someone has already done it 10 times, I just havent found anyone yet.

Anyone?

Comments

  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: Solar Hot Water controller

    I have built a flat plate collector. It is quite simple, and it works quite well on the Wet Coast. (Not our Northern Ontario house!) I too have used Goldlines in the past, but I think they are out of business.

    I installed a Azel Technology controller http://www.azeltec.com/

    It has a digital display that shows collector temp, tank outlet temp. You can set the differential T from 1C to as high as you wish. It also has a bunch of cool features including adjustable hysterisis. But the best function is the freeze protection. You can set it for what ever temp (low temp) you wish, say 35f and when the probe says 35f, it will turn on to keep the collector from freezing. This makes using a simple, potable water system simple even in climates that have moderate freeze, say 10f overnight. The last collector I built is very simple. It is nothing but ~250' of 1/2 copper pipe in a continuous loop, sitting in a wooden box, with a piece of 1/8 plate steel, on top of 2" of thermax insulation. The whole thing is covered with 2 28x76" patio door glass panes. The controller triggers a small 1gpm grunfos pump, circulating into a salvaged electric water heater, that acts as a preheat for a demand gas water heater. The whole thing cost ~$400 and delivers about 8000 btu on a sunny day in mid winter, (about 40% of 2 peoples use). In the summer I expect it to put out ~40,000 btus,, way more than we would need. ( I also wired the water heater (preheat tank) with a piece of wire that runs outside the house, so that when the owner runs the emergency generator for an exercise cycle, they can load up the genny, and heat water as a bonus!

    There is a 12vdc version from a different manufacturer: http://www.arttecsolar.com/

    I've never used this one.

    Tony

    PS In FL you could heat all the water you could ever need,, real easy, real cheap!
  • RobPattonDotComRobPattonDotCom Registered Users Posts: 11
    Re: Solar Hot Water controller

    Those are getting closer to what I want, but I sure would rather have the data from it be logged/etc so I can add the status of it to the rest of my monitoring screen. It would also be nice to be able to gather temps and run-time of the pump through the day, and be warned ahead of time if the tank temp was below x degrees. Even in FL, we do get some times that solar doesnt do so well. Right now, in fact, I've got the backup electric option on, just in case.

    My Goldline controller is only 3 months old, so they must still be in business.

    If they just offered an LCD screen/serial output option, it would be what I want.
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: Solar Hot Water controller

    Rob,

    Dig a little deeper on the Azel site. I noticed (but didn't read) a bunch of info on zone controllers and pc boards for networking controllers together for hydonic systems. Maybe in that maze there is a network interface that can be adapted.

    As for goldline. I still see them for sale, but I was searching for some information on the thermisters and ran into a dead end. Perhaps I didn't look far enough. Someone told me they were out of business.

    Tony
  • System2System2 Posts: 6,290 admin
    Re: Solar Hot Water controller

    IMC Instruments....Eagle 2 Diff Controller.

    braggs
  • System2System2 Posts: 6,290 admin
    Re: Solar Hot Water controller

    Rob, so what did you end up with?

    braggs
  • LucManLucMan Solar Expert Posts: 223 ✭✭✭
    Re: Solar Hot Water controller

    Search this site for solar thermal differential controllers. They have a few new controllers that are not available yet but are in the works.
    http://www.stecasolar.com/index.php?Solar_electronics_inverter_photovoltaics

    For all kinds of cool solar related stuff.
    http://www.steca.de/index.php?main|cat47eb8aaf4f1cc_0|2
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