Uncertainty Quantification in Building Energy Study: The Case of Local Wind Speed

• Activity Number: 469
• Type: Contributed
• Date/Time: Wednesday, August 3, 2011 : 8:30 AM to 10:20 AM
• Sponsor: Section on Physical and Engineering Sciences
• Author(s): Huizhi Xie*+ and Yeonsook Heo and Godfried Augenbroe and C. F. Jeff Wu
• Companies: Georgia Institute of Technology and Georgia Institute of Technology and Georgia Institute of Technology and Georgia Institute of Technology
• Keywords: Building Energy ; Computer Experiments ; Simulation ; Uncertainty Quantification

Abstract

EnergyPlus is a computer code widely used in simulating building energy consumption. The calculation of local wind speed in EnergyPlus, as an intermediate step of building energy consumption prediction, inherits uncertainty from the microclimate conditions caused by varying urban surroundings. This study aims to quantify the uncertainty of local wind speed calculation through the uncertainty quantification of wind speed profile exponent and boundary layer thickness. For a given terrain, different urban surroundings are generated using space filling design coupled with random sampling. The outcomes of EnergyPlus are compared with those of a higher fidelity model (meso model) for each surrounding. A predefined measure of discrepancy is minimized to obtain a set of point estimates of the exponent and boundary layer thickness for each surrounding. From these estimates, the distribution of the two parameters can be estimated using smoothing techniques. The distribution of local wind speed induced from that of the two parameters will be utilized for further calculation in EnergyPlus. This is one of the first uncertainty studies in building energy.