Thursday, February 17, 2011

How to build a solar hot water heater

   http://gan.doubleclick.net/gan_click?lid=41000000012871747&pubid=21000000000346743                                               





        This post is about a Solar Hot Water Heater I built a few years ago. It is made from scrap lumber and recycled parts and pieces. It worked great for the few years we used it. I gave it to a friend when we became full time RV ers.
In the summer it would preheat our water to our electric water tank to 130 degrees so our thermostat and electric didn't have to work very hard. The 5th wheel had a switch over the sink to shut off the power to the electric tank. We would leave it off while we were gone and would have nice free hot water when we got home. It cut our power bill in half.
       Nice to have 105 degree water going into the house in the winter. The gauge was recycled from a car and aimed at a window in the house so we could see how hot the water was in the tank.
        I added an outside thermometer to see the temp. difference. If these pictures look familiar to you its because I posted them on another site a couple of years ago.
     I plumbed the hose from the top of the solar heater to the top of the electric heater. Bottom to bottom. No pump is required because it is slightly lower than the inside one. Works by thermo siphon.
  I used a foam mattress pad cut into strips and wrapped around the hoses to insulate them, then stuffed them into some old pvc pipe. Foamed around the ends. Worked good down to around 19 degrees. There was enough warm water in the tank to keep it from freezing.
  The Parts !!!!!        I found an old galvanized fresh water tank salvaged from an old camp trailer. I cleaned it up inside and out and painted it flat black 99 cent Walmart cheap paint. For the curve part I found a piece of old perf board that had been rained on, so it already had a natural curve to it.                      
I cut 2 holes to fit the tank legs thru. I found some old used ply-wood from a construction site and cut the curve in them and made a box to put them in.
   This is not the best curve to use but I modified to use what material I had. My goal was to use all recycled materials if possible.
The size of the box was determined by the size of the glass I found in a garage sale. I used some left over aluminum backed foam insulation for the ends. they reflect the sun onto the ends of the tank.
.
     I glued an old 99 cent Goodwill Mylar space blanket to the curved peg board to reflect the sun to the sides of the tank. Bolted the tank into the box. Ready for plumbing.
Test fit for glass and getting the angle to the sun.
     Plumbing was a simple task. Top to top. I put a tee at the top of the tank to insert a Temp.sending unit fron an old car. Another tee at the bottom for a valve to drain the tank. I built a box around the house tank for more insulation.
I had to move the unit away from the house for more sun. If that wall was facing south I could have placed it against the house with very little plumbing and heat loss.
   Unit up and working, Next step was to build a second box around it with insulation in it and foam the cracks.
The insulated box around the house heater. I put a access door in it to reach shut off valves.

http://gan.doubleclick.net/gan_click?lid=41000000012871747&pubid=21000000000346743