Cost effective solution for water heating

[jasonmanning]

If I need to heat up the water of swimming pool which is on another side of my house (approx 250 w), what should be the ideal way. I am thinking to go with simple solar thermal system. The size of the pool is 15X30

Apart from solar thermal (which may cost me $3000+), what could be other alternative

[Mary B]

Get a large 1,000 foot roll of black pex tubing. Zig zag it across the ground or roof and pump water through it.

[MattM]

Pushing water through the system might not be cheap.  If you could use passive heating to collect the heat then your exchange could remain separate from the pool-side water supply and the energy to move water is drastically reduced.

[TomT]

If they elevate the tubing.
Could you not use a back flow valve to create a siphon effect type of circulation?

[dbcollen]

a siphon only works when the water ends up lower than where it started.

[MattM]

The other consideration is preventing steam entrapment via a safety valve.

[TheEquineFencer]

If I need to heat up the water of swimming pool which is on another side of my house (approx 250 w), what should be the ideal way. I am thinking to go with simple solar thermal system. The size of the pool is 15X30

Apart from solar thermal (which may cost me $3000+), what could be other alternative

Someone mentions using black pipe. That will work...if you have enough of it, no pump is needed. One end needs to be at the bottom of the pool, the other near the top. As the water inside the pipe starts to heat, hot water rises, it'll start a thermal siphon and circulate on it's own. if the tubing/pipe is too long the water itself will slow due to the water friction itself. Use a lot of shorter runs tied to a larger "manifold" pipe for the main flow.

[Bossrox]

I heat my cabin hot water with a solar collector with pex pipe looped thru it & use a small thermostatic controlled pump to dump it in a standard water heater. You could do something similar with a 500 ft loop of 3/4" black pipe in a box painted black. youtube has some vids on that. Only for winter you'd need to compressed air flush the collector to get out the water.

[MattM]

I don't see why heating water through an elevated syphon would not work.  Heated water could return to your pool from the top of the tank.  As it returns to the pool it can suck the cold water back up to replace it.  May have to prime it every so often, but otherwise should work.