Pool diverter to DIY solar heating system

[Paxcou]

I am anticipating my next spring project. We have decided to not invest in a gaz pool heater, or heat pump. We are going to build this winter a solar pool heater system as many have done already. The design could use a pool diverter valve. However the flow rate in the diy solar system will be lower than the one coming out from the pool pump. My idea is to use the valve to let 25% of the flow to take the direction of the solar system to join back the 75% of the flow coming from the pump then in the pool.

It will use this idea but not opening 100% to the heating system: Heater Bypass - Further Reading

Any suggestions or advice ?

 

[needsajet]

Personally, I'd recommend you get a kit with everything you need, and save money by doing the work yourself. That will have all the ins and outs covered in the instructions.

You'll probably need around 1/2 the flow of your pump, assuming you have a 1.5 HP pump. The pump will need enough head to reach the tipping point in your heating system, and there's every chance it has that. You'll need to consider drainage for freeze protection, possibly during your heating season, depending how you use the pool. Drainage is also done to prevent too much stagnant water staying in the system day to day, when the system is not in use.

You can control it manually, turning on when sun is out, off for clouds or end of day. You'll get more heat (unless you're perfect) by using a controller that senses pool and roof temperature. My system turns on and off several times per day, especially in spring when I want the most out of it.

For any exposed pipe, I highly recommend CPVC (the black pressure pipe). You can paint regular PVC pipe, but it doesn't last especially well in the sun, and when the system is off for whatever reason, regular PVC can barely handle the heat, and sometimes doesn't, leading to leaks.

Don't get sucked in by any ideas about long runs of half-inch polyethylene pipe. The friction loss on long runs of small diameter results in dribbles of water, not the 30+ GPM you're going to want.

Good luck with the project. It will be great to extend the swim season and also to have warmer water!

 

[Paxcou]

Thanks for your answer very detailed. I realized my answer was not posted. Really appreciate the time you spend to answer me with a great level of details.

 

[needsajet]

Happy to help. Cheers