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Abstract: Buildings are huge energy consumers and are responsible for a large part of greenhouse gas emissions in the world. Among building energy efficiency measures, solar shading plays a significant role in reducing building energy consumption, especially in hot summer and cold winter zone of China. This paper carried out a field measurement of shading performance of movable shades installed on the south-facing facade of a residential building in Ningbo city of China. The field tests show that external movable solar shades have a good shading performance that can reduce solar transmittance to about 8% and keep indoor illuminance at about 1000 lux with little fluctuations, indicating a suitable level for indoor environments. A building simulation study on energy, indoor thermal and visual performance of movable solar shades was further carried out. Several important indexes were adopted to give an in-depth analysis, including energy performance, room base temperature, transmitted solar radiation, PMV-PPD and its distribution as well as Discomfort Glare Index (DGI). Results show that movable solar shades used for south-facing windows not only reduce building energy demand by 30.87%, but also improve indoor thermal comfort by 21% in summer as well as reduce dramatically extremely uncomfortable risks by 80.4%, and meanwhile the visual comfort condition is also improved by 19.9%. [Copyright &y& Elsevier]

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. Image 1 • An air conditioning (AC) behavior model was used for energy and economic analysis. • Monte Carlo simulation was combined with statistical test for energy prediction. • Indicators were proposed for uncertainty and convergence quantification. • Cooling energy uncertainty is significant at different temporal scales. • Energy and economic savings are over-predicted by standard-based AC setting. [ABSTRACT FROM AUTHOR]