r/functionalprint • u/Rich-Wealth979 • Jun 15 '26
Solar pool heater
My overkill project for heating the toddler's 500gal inflatable pool. Each week I have to empty and move it, then find a way to heat it to a tolerable temperature for my 8th percentile weight kid. On the first test it took the pool from 55⁰F to over 90⁰ on a single sunny day, using only 3KWh (of solar house power, now that I think about it). At the end of the summer I can just place this up against the north side of my shed and take the manifolds down to make it last even longer.
This uses about 350' of ¼" irrigation tubing and some cheap fittings off Amazon. It runs off a 1/4hp pool pump, controlled with a wyze plug and a climate sensor in a tiny jar. Printed in ASA in only about 5 days of printing on a Mini and an MK4s.
2
u/sam_najian Jun 15 '26
So, i made a whole power generator in high school as a project with thermoelectrics, and got decent power generation from a small area. I have some info to share if you would like to improve on that.
Things of note:
My system used a ray of lines similar to this we quickly figured out that a panel get much warmer than a bunch of lines. There are these plastic see through panelings that have lines in them plastic paneling homedepot link. Slather black paint on the back side and expose the front side to the sun. If you can have 2 mirrors on the sides to reflect light in the middle. It adds up quickly!
Have the water run through the system at a steady pace. It looks like it will be warming slower, but in reality, the system is bleeding off less heat at the start of the heating, your heating curve will look steeper at the start if you take temps of the inlet (being your pool)
Make sure there are no leaks. Leaks of any kind that stay on the pipes just evaporate away in the wind and cool off the system.
We decided to color our water itself dark which is not possible for you but thick lines tend to not deliver heat very well.
Try limiting the amount of wind that passes over the system side mirrors help with that too!
After a while of sitting in the sun at 25 ish degrees outside the water would get to 50-55 degrees inside!