Everything takes time and money. The solar pool heat project is no different. I have put together a system based on the old copper collector and a new stainless steel heat exchanger.
This is the system design.
I purchased a solar control system way back in Arizona when I thought I would add it to the black plastic solar heat that I installed for our pool there. I never did that but still had the controls.
A new purchase from Amazon was a 155000 btu heat exchanger in stainless steel so that the salt water would not corrode the copper. I had no idea the item would be shipping from China. I wish that Amazon made that more obvious in their listings.
These heat exchangers are specifically for pools or other water warming or chilling functions. There is a series of tubes that run inside the shell. The tubes transfer heat from the collector system to the water that runs through the shell. The exchanger should work in a thermosiphon system installed above the top of the collector.
In the basic plumbing diagram above there are two three way valves. I purchased a heavier duty Hayward valve for the controller and valve mechanism. The second valve could have just been a tee but I liked the idea of another shutoff if needed. The larger Hayward valve is usually set to have the cold to the collector off but it would open automatically when sensors read a warm panel temperature and cold pool temperature.
The cold pool water input uses pool hoses and the hot water output is mostly PVC pipe. At the bottom I used pool hose because the water should just be warm when it reaches the pool hose. Just before the pool hose there is a Fernco sump pump check valve that will prevent water from reverse siphon.
The big problem with the install is the constant leak where the valves for the solar system attach to the pump. It turns out that the Intex pump has a metric connection while the PVC plumbing is NPT. So I am waiting for a conversion piece that I will be able to attach instead.
I am hoping one of these edges will accept a slip PVC connection to hold the dual valves even though they are set up for a hose connection. Then I should be able to reinstall the valves without a leak.
I also ordered a new salt cell holder from Intex and a new O-ring for the salt cell. I’m hoping these new parts will stop the current leaks at the salt cell.