I am designing a compact home on a high elevation in Colorado. There will be a finished basement apartment on a concrete slab and I was thinking of spiraling PVC pipe through the slab to heat it. Instead of converting solar to electric and incurring transformation loss in the process, I was curious if some of my solar farm cells can be dedicated to directly heat the water in the tank before it is recirculated through the floor pipe as more efficient. What types of setups/equipment is available?

1 Answer 1


A common design in my area is a heat exchange tank upstream of a traditional gas or electric water heater. They use ethylene glycol (antifreeze) that circulates by thermosiphon action from a solar panel to the tank. The illustration below shows a more complicated (with pump and controller) version. So, you heat a tank of water with a coil full of antifreeze that is naturally heated and circulated.

enter image description here

  • Did you design this illustration yourself or where did you get it? (Ya know, give credit where credit is do...) Jan 26, 2016 at 14:50
  • I did not draw this and in all honesty I don't remember where I grabbed it (off the internet) from. I have experience in home plumbing and my neighbor had a solar thermo-siphon system when we bought our house next door. I thought it was a brilliant set-up and studied it carefully. Alas, through neglect it became unusable for them and I first bypassed it then removed it for them. I still wistfully plan on a homemade system of my own. Jan 27, 2016 at 3:10

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.