HI-85-17-1 -- A Comparison of Traditional Degree-Day and Variable-Base Degree-Day Predictions with Measured Consumption of 20 Houses in the Denver Area PDF

The heating consumption predicted by the traditional modified degree-day method and variants two of the variable-base degree-day method is compared with the weather related portion of metered gas consumption for 20 houses in the Denver Metropolitan Area. The average consumption predicted by the traditional method was 1.82 times the metered use, and the average prediction of the VBDD approaches was 1.45 and 1.44 times the metered use, respectively. The average balance temperature of the 20 houses was calculated to be 59 .8 F (15.4°C) and 56.5 F (13.6°C), respectively, while regressed billing data indicate an average of 57.5 F (14.2°C). The discrepancy between calculated and metered consumption appears to be due to calculated values of BLC/n which are systematically larger than empirical values and to incomplete gain utilization.

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