To control a domestic solar hot water system, a custom controller was built using the Arduino Duemilanove. It reads temperature inputs from the tank and roof sensors to drive a relay that turns the circulator pump on and off. Temperature readings are sent via serial port to a laptop which records and graphs the temperature data. The graphs and data are sent wirelessly to a web server, that displays the current temperatures and status using a Google Gadget.
The domestic solar hot water system is fully functional. Still some minor things to tweak, but almost there. See live system status here. You can also read some details on the installation of the collectors and the building of the heat exchanger, and there are some construction photos here.
Installation of a domestic solar hot water system. The system was originally installed on a house in the early 1980′s and was in use for around 10 years. The system was removed and not used for the next 15 years. Some parts and components have disappeared. The system is a water-based, open drain-back system. It [...]
Ok, a few quick things since I´m tired and tomorrow we bus to Chile. We left Bs.As. by plane and arrived in El Calafate, AR. Nice airport and a much nicer climate. No military guys stopping us every few hours like on the bus from Iguazu. The hostel was in a very nice setting, up [...]
