This project will focus on using an Arduino and Cayenne to monitor, and eventually control, my solar hot water system. We recently moved into a house that has an older solar collector system, storage tanks, hot water boiler and radiant heating system throughout the house. I’ve never had a solar system or hot water heating before so this is a new experience. The “mechanical room” is small but packed with pipes, pumps, valves, and tanks. I have begun the process to map out the system so I can hopefully understand how it all works. I was encouraged by gamoxristos project posting as it is very similar to what I am facing. The first sketch of the components is incomplete but will help me get started. I am beginning to make some sense of it and will soon be able to separate the various sub-systems into individual schematics and create some better drawings.
The existing controller is an old analog C-100 System Manager by Independent Energy, Inc. which still works fine but is limited to displaying the temps of the collector and storage tank only. I would prefer to get much more information on how the entire system is operating. I’ll be using an Arduino on this project and I have ordered the following to support the project:
- SunFounder DS3231 RTC Real Time Clock Module High Precision
- SunFounder Ethernet Shield W5100
- SunFounder 5V Relay Shield Module
- DS18B20 Waterproof Temperature Sensors (x5)
My analog controller is set to turn on the circulation pump based on the temperature differential between the collector and storage tank. It turns the pump on when the collector is 20 deg F hotter than the storage, and turns it off when the difference is 5 deg F. It also has a “high limit” feature which is currently set to 163 deg F. If the storage tank reaches the high limit then the circulation pump is turned off.
I plan to monitor the following points in the system:
- Collector Temp
- Storage Tank Temp
- Solar Intensity (not sure how to do this)
- Boiler Status (on/off)
- Piping Temps to/from collector (this is a drain down system and there may be a problem with improper drainage and potential freezing)
Eventually, I would like to replace the analog controller and control the pump from the Arduino.
Waiting for the parts to arrive…