My wife & I bought one of those large Above Ground Wal-Mart pools. It's 14 feet in diameter and 3 and a half feet deep. I prepared a nice place outback and put up the pool. Well It's July and I think the water is too cold to stay in it for a long time, so I decided to build a Solar Pool Heater for the weeks of cloudy days and to extend the swimming season an extra coupla months in the Spring and Fall.
I had seen this on the internet before and it's not difficult or expensive. In it's simplicity, all you do is run the Filter water through some Black Pipe that's sitting out in the Sun. My only cost was the Pipe & Valves, Black Paint, Wood for Frame and some hardware, About $100.oo in all for the parts.
The water pump comes with the pool and has 1 inch fittings with 1 1/4 flextube. I decided that I would have 80 feet of Black Pipe with 10 feet of regular PVC coming and going to the pool. This is a total of over 100 feet, so I wanted to oversize the pipe to 1 1/2 inches to help overcome the friction and reduce the Head that the pump can see. Also when I'm shopping for the 90 degree corner fittings, I found that pipe 1 1/4 inch and under had hard 90 degree angles, but corners 1 1/2 inch and over had long rounded curves that would help reduce the Friction Head involved with the water changing direction 90 degrees every so often.
Being so concerned about the extra friction of 100 feet of pipe, I decided to split the flow into into 2 pipes through Y connections so the flow would decrease to Half in these areas. If you want to follow the flow in the picture, the input to the heater is the pipe crossing to the right closest to the camera, and the output is the lefthand pipe at the open 90 degree fitting.
After constructing the unit I placed it on top of a metal shed that is adjacent to the pool. The shed is silver so any sunlight that passes through is reflected to the underside of the pipes to increase efficiency. This is not a great picture but you can find the heater on the shed because a bird is sitting on it.
I figure that in the hottest part of the year I won't need the heat so I have installed a coupla valves that will allow me to Bypass the heater after the water goes through the filter.
Today was the day that I installed it all and I have it actually working at this time. When I first turned it on, some very warm water came out as the first water absorbed the heat stored in the pipes. It was late in the day around 5:PM in the evening so the Sun was getting pretty low in the sky. I don't have any thermometers in this project so all I can do is feel the pipes and water. Although it was late afternoon Sun, I could easly feel that the watter returning to the pool from the heater was somewhat warmer than the water that was already in there. I can't wait for the Noonday sun tommorrow for a better test.
I read somewhere (not sure if it was here) that someone was taking the pool water into the house and using it to cool the house which in turn heated the water for the pool, now that's efficiency!
--------------
This story was originally posted on 7-8-03 and is here with comments
http://www.fieldlines.com/story/2003/7/8/19177/93125
I'm just moving it to my Diary as it seems that People really do read those Diarys
--------------
)}- W o o f -{(
