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An Improved Procedure for Developing a Calibrated Hourly Simulation Model of an Electrically Heated and Cooled Commercial Buildling
Abstract
With the increased use of building energy simulation programs, calibration of
simulated data to measured data has been recognized as an important factor in
substantiating how well the model fits a real building. Model calibration to measured
monthly utility data has been utilized for many years. Recently, efforts have reported
calibrated models at the hourly level. Most of the previous methods have relied on very
simple comparisons including bar charts, monthly percent difference time-series graphs,
and x-y scatter plots. A few advanced methods have been proposed as well which
include carpet plots and comparative 3-D time-series plots. Unfortunately, at hourly
levels of calibration, many of the traditional graphical calibration techniques become
overwhelmed with data and suffer from data overlap.
In order to improve upon previously established techniques, this thesis presents
new calibration methods including temperature binned box-whisker-mean analysis to
improve x-y scatter plots, 24-hour weather-daytype box-whisker-mean graphs to show hourly temperature-dependent energy use profiles, and 52-week box-whisker-mean
plots to display long-term trends. In addition to the graphical calibration techniques,
other methods are also used including indoor temperature calibration to improve
thermostat schedules and architectural rendering as a means of verifying the building
envelope dimensions and shading placement. Several statistical methods are also
reviewed for their appropriateness including percent difference, mean bias error (MBE),
and the coefficient of variation of the root mean squared error.
Results are presented using a case study building located in Washington, D.C.
In the case study building, nine months of hourly whole-building electricity data and
site-specific weather data were measured and used with the D0E-2.1D building
simulation program to test the new techniques. Use of the new calibration procedures
were able to produce a MBE of -0.7% and a CV(RMSE) of 23.1% which compare
favorably with the most accurate hourly neural network models.
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Citation
Bou-Saada, Tarek Edmond (1994). An Improved Procedure for Developing a Calibrated Hourly Simulation Model of an Electrically Heated and Cooled Commercial Buildling. Energy Systems Laboratory. Available electronically from https : / /hdl .handle .net /1969 .1 /86260.