The term "Solar Energy" is being bandied about as the solution to all energy problems. It can help, but that is all.

I have reduced my Gas bill to nearly zero in the summer, by using a solar water heater I made out of 2 inch plastic pipe. Friends have suggested I give construction details, so here it is.

First: I do all my bathing in solar heated water. So the only gas heated water I use is for washing washing a few dishes, and laundry about once a week. This photo is my bathtub. It is a 150 gallon RubberMaid cattle trough.

• Plastic "Rain Gutter" is hanging near the top, to carry the over flow to the 30 gallon garbage can.
• In the garbage can is a submergible sump pump. Its' outlet is going to three garden hoses.
• The water goes into the tub through the drain which is to the right of the garbage can.
• On the back of the chair are two plastic U-pipes which I made to syphon the water from the tub to the garbage can when I want to drain the tub.The larger one made from 1 1/2 inch pipe works best.

To fill the tub I run the water from the garden hose faucet through the heater which is 8 twenty foot length of two inch PVC plastic pipe. I join two lengths to make a 40 foot pipe, then I use a U bend to connect to another 40 foot pipe. To make it possible to drain I don't permanently connect this to the second "40 foot U-pipe"; but instead connect these with a short piece of garden hose. These just lay in the dirt along my back fence in the sun.

A group of detailed photos of my simple solar water heater follow.

The 2 inch U-bends are part of a P-Trap. If you can't find U-bends use two elbows. Ideally, one of the elbows would be a "slip-slip street elbow".

The pipes and the U-Bend should all be glued together before painting them black. Wal-Mart has "Black-satin" paint in spray cans made for painting plastic. For the 80 feet of pipe I used two cans.

I put the pipes up on cinder blocks to make them easier to paint.

I connect to the pipes with ordinary garden hose connections.

Incidentally, in this photo you can see against the fence the old ABS black pipe I first used.

For this use I do not recommend ABS pipe because it is somewhat porous and water seeps through the walls. It leaks in a few spots where I suspect there was to much "filler" put into the plastic when the pipe was made. ABS is sold for drain and vent use where there is little or no pressure and oozing through the wall might be tolerated.

White PVC is sold and used for carrying water under pressure. I have not seen any leaking through it. But, I am told PVC does deteriorate when exposed to the sun light, which is another reason to paint it black; which significantly increases the absorption of the heat.

I want the male hose connector (the outlet) to be at a high point so air bubbles will get drawn out of the pipes. So, I used an elbow before reducing for the male hose connection.

• 2 inch Street elbow.
• Bushing 2 inch to 1 inch. I could not find a 2 inch male to a 3/4 female threaded bushing. Later I found them at Lowes.
• 1 inch male to 3/4 inch female threaded bushing.
• 3/4 inch threaded street elbow.

The connection on the right will be the outlet. The elbow is to make the outlet be the highest point.

This photo is before I put the hose fittings in, but after I had glued the fittings in and painted the pipes black. I didn't paint the fittings, because if there were leaks I would have to cut the pipes off and replace the fittings. The paint would probably interfere with the cement.

If you haven't worked with larger PVC pipe, I should warn you: the cement dries quickly. So you need to work fast, and be liberal with the cement. It seems to lubricate the joints and make them slide together easier.

Here the new section of pipes, is nearly complete. It is made of four 20 foot lengths, with a U-Bend.

Against the back fence you can see some of my older pipes. They were black ABS, but ABS leaks through the side. The new pipes are PVC painted black. Black absorbs more heat, and the paint hopefully will reduce the deterioration caused by the sun light.

Unfortunately the wide angle lense makes the distant sectiions of the pipe look shorter and smaller. The white past the 2nd blocks is the middle join of the twenty foot sections of pipe.

A close up of the middle joints, joining the two 20 foot lengths together.

I did not paint right up to the fittings just incase one leaked and I had to saw it off and make a new joint.

Here, I have moved the new PVC pipes near the older ABS pipes, and put the hose connections on and connected the hoses.

Because I have them, I am still using the older ABS pipes. The oozing through the sides is not too bad. I have used them for about five years.

The older ABS block used three U-Bends. This worked OK but it is nearly impossible to drain all the water out. I would recommend using only one U-bend and use removable connectors so the pipes can be drained. Unless you have lots of help it is almost impossible to move the pipes when they are full of water.

I have room against my back fence (which runs east & west) for more than 40 feet of nearly level pipes. The newer ones, made with PVC, are just 40 foot U-tubes.

To get more hot water I made a second set. Giving me a total of 160 feet of new pipes, plus 80 feet of the older ABS ones.

This photo shows the U-bends of both. The latest is the one painted all black.

They work well and gave me enough hot water I was able to fill the 150 gallon tub with 90 degree water when the out door temperature was below 60 degrees, but with full sunshine. Yes, it is cold when I get out of the warm water! It makes one hurry to dry off.

Here both are against my back fence and all connected together.

In the upper left you can see part of a 4 inch ABS pipe I made a few years ago. It was an experiment, but 4 inch heats too slow. I have moved it against my west fence so it gets the early morning sun. Supposedly it pre-warms the water early in the morning for the main pipes. It gets the first water from the faucet, and doesn't hurt anything; but I wouldn't recommend larger than 2 inch pipe.

Summary

The water simply comes from an outside faucet and the water goes through the pipes and into the tub. After the hot water has been pushed out of the pipes, colder water follows. Surprisingly, it doesn't seem the hot and cold water do much mixing in the pipes. The water comes out hot and quite suddenly turns cold.

I drain the tub every time I use it. This way I never have to use filters or chemicals. Nor do I have standing water to breed mosquitoes.

Obviously, the pipes need to be where they get full sun most of the day. In the summer in San Jose, CA where the temperatures rarely get over 90 degrees, you need about one foot of black two inch plastic pipe for every gallon of tub. This will give a tub full of water around 90 - 95 degrees by about 10 AM. And another tub full every couple hours. In the spring and fall when the days are not as hot, you may want more pipe.

The pipes need to be emptied, to move them and in colder climates to prevent freezing. I found zig-zagging four pipes using three U-bends, makes them almost impossible to drain. I believe with one U-bend the water will eventually drain out if propped up to have a slight slope. With the pipes joined to make a 40 foot straight run this may take a while. So far I have not tried to drain either of these.

As to the cost: I paid about $15 for each of the 20 foot lengths, four of them was $60. Connections, paint, glue, and connecting hose; probably made the cost near $100 for 80 foot of heater. The tub was around another $100, the same for the sump pump. Garbage can, cinder blocks (one layer high would be enough) and carpet are probably another $100. I think this adds up to about $400. Adding another 80 feet of pipes for another $100 could be done later. More pipe provides more hot water, and takes less time to get a tub full of comfortable warm water. But with more pipe you will want to have an easy way to add cold water when the pipes still have hot water in them.

Be warned, the water can get hot enough to scald you. And, water that just feels warm will kill lawn grass. Through a simple sprinkler, it cools enough before it hits the ground to prevent any damage.

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