Uncertainty Sources and Calculation Approaches for Building Energy Simulation Models

Abstract To design buildings with high energy efficiency is a primary objective of green building design. Architects and engineers rely on building energy simulation models to calculate the energy consumption of buildings and to assist them in making design decision. However, none of the building energy simulation models is immune to the influence of uncertainties. Uncertainty is associated with building energy simulation models and efficient design of building energy is an important subject in the field of building physics. This paper starts with introducing the concept of uncertainty associated with efficient design of building energy, followed by distinguishing two types of uncertainty, namely subjective uncertainty caused by designers and objective uncertainty rooted in energy simulation models. The focus is placed on identifying different categories of uncertainty sources involved in energy simulation models using EnergyPlus as a representative. Three categories of uncertainty sources are analyzed and the means to quantify them are discussed. Finally, uncertainty transfer involved in the EnergyPlus model is studied. Three approaches to calculate the uncertainty of the output parameter, i.e., the space conditioning load, are proposed.