Nathan did a really nice job of building and documenting his solar water heating system.
The system is an offshoot of the $1K solar water heating systems with some useful new design features.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiF2hWd1luvxdyTI9_mD_lbsuuuW1AYV0N75q9hpj4tUfCqd1zvE3k0pFc8-u9iqrxakdyTK4yUCh9_AgBqKM8o-Uvdh67XEyzXmsxrw8tfMUr5oMz6A6C8MPZDLAu8SJhjRfaXMOTkYaVT/s400/Nathan1K01.jpg) |
The twinwall glazing is a very nice look. |
The system uses the usual 300 ft coil of PEX pipe as the heat exchanger, but Nathan recoiled the PEX for better heat transfer performance:
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjRR8j2x18NlkpYEnVyW_u7YPJrPuQ_sZ8qwLJxt5cwchQ-QEl91aK5BrHiqqs4jpz2vdlbSgx2aZQBamFcAlGFzkIUrXeTWamj_2hFIBCSqr4DXjKiMlIemUl0I5GwRa-97Kt7sVkdBKsv/s320/Nathan1K02.jpg) |
The 300 ft of PEX is recoiled into a two layer coil for
more water exposure to each coil. |
Be aware that this recoiling can be a challenge -- think about about your method if you don't want to end up imprisoned in a coil of angry PEX.
Nathan also offers details and source code for making an open source Arduino based differential controller.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgt042AUy8uKO4BEsH0Li2hYPA_Ux8zhg3GIK4qN796in4SgCVgPkBq-q_RUONi7FU4EcgyfJ9wzCgLcdp3U42nuSgg6hBQSVE1lZ2yZMK1xyI09p3hUsiRFckMLPKytYwZXSs_W6Tc2UR1/s320/Nathan1K03.jpg) |
Arduino based differential controller. |
Nathan has the Arduino based controller equipped with an Ethernet shield. This allows the Ardduino to log data directly through his router to an free online logging service called
pachube.com -- there is no need to have a PC running 24/7 for this kind of logging, and it gives you access to the data from anywhere -- very nice!
All the details on Nathan's website....
For more on the $1K solar water heater and dozens of other DIY solar water heaters...
Gary