Author Topic: Solar Pool Heater  (Read 9223 times)

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Offline WooferHound

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Solar Pool Heater
« on: February 02, 2012, 03:26:00 pm »
My wife & I bought one of those large Above Ground Wal-Mart pools in 2003. It was 14 feet in diameter and 3 and a half feet deep. I prepared a nice place outback and put up the pool. Even in July the water was too cold to stay in it for a long time, so I decided to build a Solar Pool Heater to extend the swimming season an extra few weeks in the Spring and Fall.

 I had seen Solar pool heaters on the internet before and it wasn't difficult or expensive. In it's simplicity, all you do is run the pumped filter water through some Black Pipe that's sitting out in the Sun and return the water to the pool. My only cost was Pipe & Valves, Black Paint, Wood for Frame and some hardware, About $100.oo in all for the parts in 2003.

 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 backpressure that the pump can see. Also when I was shopping for the 90 degree corner fittings, I found that pipe 1 1/4 inch and under had hard 90 degree angles, but 1 1/2 inch and over had long rounded curves that would help reduce the Friction and pressure involved with the water changing direction 90 degrees at every turn.

 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 follow the flow in the pictures you can see a couple of sections that are split to create slower flow in those areas.

 After constructing the unit I placed it on top of a metal shed that was adjacent to the pool. The shed is silver so any sunlight that passed 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 is pumped through the filter.

In 2005 I moved to a new house and of course we took the pool heater with us. We got another Above Ground Pool that was a lot bigger and held twice as much water. I mounted the heater on the privacy fence and this time it was all below the level of the water when the pool is full.

I used the same hookup as the first time, where the water is pumped through the filter pump, then through the heater and back into the pool. Next year I plan on using 2 separate pumps, one for the filter and another for the pool heater. This will give me a little more control and I will not need the bypass valves anymore. I have also installed a way to drain the pipe for the Winter.

All I can say is that it works pretty good. I don't have any temperature measurements and I have no idea how much heat I'm gaining through the system. In the middle of the Summer I need to turn off the heater as we don't like the water to get much over 86f (30c) degrees. The water flows better when the unit is below the water level like in the second installation.

 I read somewhere 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!

There are more pictures of this in my photo gallery here . . .
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Offline bj

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Re: Solar Pool Heater
« Reply #1 on: February 02, 2012, 05:04:17 pm »
   Pretty slick  Woof
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Offline frackers

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Re: Solar Pool Heater
« Reply #2 on: February 02, 2012, 05:09:12 pm »
I have had a similar (although larger - 38ft x 15ft) pool for some 8 years but it was put in-ground by digging a large hole!! The spoil heap has made a perfect place to put the solar.

Its some 50 square meters of a sandwich (from bottom to top) of 40mm polystyrene sheet, black weed cloth weave, pipes, 100mm air gap polytunnel house plastic cover.

The pipe is a neoprene ribbon, each section being 4mm bore and 14 pipes wide (looks like overgrown ribbon cable!!). 63 lengths  between manifolds at the top and bottom of the panel 5m apart giving about 1.6km of pipe (just over a mile!!). It extends the swimming season from 1 month (just about warm enough) to 7 months of the year with a minimum water temperature of 24C. A separate pump and controller looks after the maximum - like you, more that 30 is uncomfortable (although I did override it once to get to 40C - very dodgy temperature to try and swim in!!.

The panel is above the pool so it has an automatic drainback by having a foot valve at the top - this seals under pump pressure but opens to allow in air when the pump stops and hence the water drains back to the pool - automatic frost protection :)

Robin Down Under (or are you Up Over!)