[rrd-users] graphing hvac thermostat?

James Russo jr at halo3.net
Sun Apr 1 02:30:41 CEST 2012


	I'd like to figure out what might be the best way to intelligently graph HVAC thermostat for a project I am working on. I have an RRD file with temperature, cooling setpoint, heating setpoint, cool flag (are we cooling 1/0) and then heat flag (are we heating 1/0).

Anyone have some examples they can share or suggestions on how I might setup the def's to graph what I need. Thinking about a line for heating/cooling setpoints, but I'd like to see some indicating of when we are cooling or heating. I've experimented with using a CDEF and multiplying the temperature by the heating/cooling value, but its not working as I expect. I don't get an instant jump when calling for cool.. It kind of steps up and I assume this is due to the averaging. I would have expected to graph temperature when not cooling or heating, graph cooling in a different color when cooling and same for heat. 

It would be nice to just throw a vline when calling for cool or heat, but I don't think it is possible to capture the "transition" of the values and determine the time to put the vline at. 



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