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Heat/cold degree days and Chill hours: Difference between revisions
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Heat/cold degree days and Chill hours (view source)
Revision as of 11:22, 3 January 2013
, 11:22, 3 January 2013→Cold Degree Days: sentence added about matching thresholds
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You may have a thermostat that makes a cooling system come on when the temperature rises above a threshold. | You may have a thermostat that makes a cooling system come on when the temperature rises above a threshold. | ||
Cumulus calculates an integration of the number of degrees above | Cumulus calculates an integration of the number of degrees above a threshold you select over the time that the temperature is above that threshold. | ||
Cumulus reports this by month as part of the NOAA report, in the annual NOAA report, in dayfile.txt, and via cooling degree days web tag. | Cumulus reports this by month as part of the NOAA report, in the annual NOAA report, in dayfile.txt, and via cooling degree days web tag. | ||
If the threshold you select in Cumulus matches your thermostat, the reported value gives you a measure for how hard your cooling system has worked; otherwise it is a statistic that gives you a feel for how hot it has been. | |||
So if for one day in June, successive readings at one minute intervals above the threshold were 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, then it stayed 10 degrees above for 1 hour, before falling in successive minutes to 9, 8, 7, 6, 5, 4, 3, 2, and 1 degrees above the threshold, the total for that day (of 1440 minutes) would be 150 degree minutes reported as 150/1440 or 0.1 degree days. | So if for one day in June, successive readings at one minute intervals above the threshold were 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, then it stayed 10 degrees above for 1 hour, before falling in successive minutes to 9, 8, 7, 6, 5, 4, 3, 2, and 1 degrees above the threshold, the total for that day (of 1440 minutes) would be 150 degree minutes reported as 150/1440 or 0.1 degree days. | ||
