Uncertainty analysis in building simulation with Monte Carlo techniques

From a modeling perspective, the thermal characteristics of buildings must be described with the help of parameters that often cannot be estimated with high accuracy. Results from simulations relying on erroneous parameter values can lead to inaccuracies which are hard to quantify, and small perturbations to a sensitive parameter can influence the results significantly. By examining the impact of uncertainties, it is possible to increase simulation quality, and thus inferences from the results. In this paper, the uncertainty associated with model parameters of a building using a solar thermal collector for heating and domestic hot water is analyzed. The influence of the uncertain parameters and variables on the solar fraction is quantified through the use of Monte Carlo simulations. The relationship between uncertainty analysis and sensitivity analysis is examined, as well as a practical methodology suggested to support the building design process and related decision making.