[rrd-users] need help with figuring out how many minutes furnace is on

Haroon Rafique haroon.rafique at utoronto.ca
Wed Nov 7 15:57:25 CET 2012

On 2012-11-06, at 7:22 PM, Steve Shipway <s.shipway at auckland.ac.nz> wrote:

> Simon said:
>> I'd suggest you want a DS for heating which is either 0 (off) or 1
>> (on), and update this as often as you can. And have a separate DS for
>> cooling, again 0 or 1.
> I strongly agree; otherwise this makes higher-granularity graphs very awkward, unless there is a 1cdp=1dp RRA that goes on forever to avoid averaging, which would have other problems, of course.
> If you cannot do the calculation before storage, then maybe define two calculated DSs that that the status DS (0,1,2) and convert to on calculated DS that is heating 0/1 and one that is cooling 0/1 ?  Once you have this, then it is easy to get percentage use time -- just create an RRA that is 1cdp=1day and the average of the heating DS x100 is the percentage time the heating is on that day!  Much simpler to do all the necessary calculations.
> Steve

Thanks Steve and Simon,

I'll redo the DS structure with a separate DS for heating and a separate DS for cooling. Obviously, I didn't think clearly about storing 0, 1, 2 as the mode values straight in the DS.

And to answer Simon's query, it is indeed a variable-speed, modulating, variable capacity (need more buzzwords here) furnace. But, alas, the website JSON data won't tell me what capacity it is running as. (Or I haven't looked hard enough at the correct places). All I get is the state of operation.

Haroon Rafique   <haroon.rafique at utoronto.ca>
Information Security & Enterprise Architecture, University of Toronto

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