New method of equivalent energy consumption for evaluating thermal performance of energy-saving materials in passive buildings

Abstract

To simplify the evaluation of the energy-saving performance of materials in passive buildings, a new method of equivalent energy consumption is proposed. The principle is to integrate the difference between the surface temperature of envelopes and the ideal temperature. This method quantifies the difference between the actual and ideal situation, without the need to combine the results of multiple indices for comprehensive evaluation. The reliability and efficiency of this new method are analysed by taking the top floor room with phase change materials used in Guangzhou as an example. The important parameters including phase change temperature, thermal conductivity, and latent heat, are selected and compared with the optimization results obtained by other traditional indices using the method of equivalent energy consumption. The optimization results of multiple indices are found to be the phase transition temperature of 35 ℃, thermal conductivity of 0.2 W·m-1K-1, and latent heat of 300 kJ·kg-1. The method of equivalent energy consumption is consistent with it in many examples, which proves its reliability. Taking the case of traversing the phase transition temperature as an example, it only takes 7.2 min to obtain the equivalent energy consumption and optimization results. However, when using other traditional methods to optimize the parameters of the same case, approximately 7 h of extra time is needed to process and analyse the data until the conclusion is obtained, excluding the calculation time. Therefore, this accurate new method makes it convenient and efficient to evaluate the energy-saving performance of materials in passive buildings. Moreover, the new method is suitable for different regions, climates, and architectural backgrounds, and researchers can use it according to their own needs.