Sensitivity analysis on energy performance, thermal and visual discomfort of a prefabricated house in six climate zones in Australia

Abstract

In prefabricated buildings distinctive construction process and lightweight components affect design strategies and consequences. Therefore, to create more sustainable prefabricated buildings, it is important to understand the effects of their envelope parameters on energy performance and indoor environmental quality. Although previous research have investigated the effects of envelope on energy and indoor comfort outputs, the parameters of lightweight prefabricated envelope are not thoroughly considered. This article quantifies the effects of building envelope parameters on the energy use, thermal comfort and daylighting levels of a prefabricated house built in Australia. A building simulation model was developed and validated by comparing predicted with measured indoor temperatures of the house. The baseline performance for evaluation of energy consumption, thermal discomfort hours and daylight unsatisfied hours were carried out using Transient System Simulation (TRNSYS) tool. Series of regression-based sensitivity analyses (SAs) to identify the most sensitive parameters were conducted by coupling TRNSYS, jEPlus and SimLab. Applications in six climate zones were investigated. The important focus areas found by SA in each climate and their corresponding design responses can be applied across ranges of prefabricated building projects if built in similar climatic conditions. SA results revealed window glazing and shading among the most influential parameters on all targeted performance outputs. The relationship between sensitivity levels to energy consumption and degree days indicated that the type of window has a higher impact on the reduction of energy use in the cooling dominated climates while insulation of wall was found a more effective strategy in heating-dominated climates.