Building cooling energy uncertainty and life cycle economic performance: A stochastic air conditioning behavior model based comparative analysis

Abstract

This paper investigates the energy and economic uncertainty of residential apartments using a stochastic AC behavior model and evaluates the appropriateness of existing building standards/codes-based AC setting in predicting energy and life cycle economic performance of energy-saving measures (e.g. wall insulation) in hot summer and cold winter zone of China. Monte Carlo simulation, distribution fitting and statistical tests were used to conduct relevant analysis. Results show that cooling energy uncertainty at different temporal scales is significant ranging from 8.59% (annual) to 70.22% (hourly) while standards/codes-based AC setting does not provide uncertainty information. The widely used simple assumption that the relative values of the energy-saving effects in actual are the same as those in thermal simulation (standard-based AC setting) is incorrect and there is a significant overestimation of cooling energy saving by standard-based AC setting. Further life cycle economic analysis of adding wall insulation shows that standards/codes-based AC setting may overestimate net present value (NPV) by about 1243.82% and lead to an inappropriate design decision when comparing different energy-saving measures. Therefore, existing building standards/codes-based AC setting may lead to biased energy and economic prediction of energy-saving measures and recommendations on future building standard and policy improvements are provided.