I have boiler which is heated up by burning logs. I've just installed heat meter which I can read by RS-232, or actually meter transmits data periodically to Node-Red, such as current heating power (kW), inlet and outlet temperature (C), flow (m3/h) and total amount of produced energy (kWh). Total energy is increasing number from day 0, cannot be reset.
GOAL: To save & show last 5 heating sessions total amount of energy (kWh).
- How to automatically decide, when new session is started (SOLVED: Flow <> 0)
- Save previous "total" energy to database or file.
- Visualize last 5 values
Easy way to see when heating is stopped is the flow. Boiler charging system pump will be stopped after heating sessions. Next time it will be started at new heating session.
Total produced heat could be something like "current total energy - total energy before current session". Another way could be by reading current power, but resolution might be problem. 5 mins is shortest upload interval I can set into heat meter