Comparison of ground coupled heat transfer models for predicting underground building energy consumption

Abstract

Underground buildings have gained attentions to alleviate urban land-scarcity. Evaluation of energy performance remains complex and uncertain for underground buildings, where the heat transfer through building envelopes is a typical three-dimensional unsteady heat transfer process. A few models have been proposed to calculate the ground coupled heat transfer (GCHT) through underground building envelopes. This paper evaluates and analyzes the influence of different GCHT models on energy consumption prediction of underground buildings. The models tested include: Ground Domain Xing (EnergyPlus), Basement Preprocessor (EnergyPlus), Foundation Kiva (EnergyPlus), and Frequency Response Analysis (DeST), which are compared under the criteria of consistency of model outputs and computational time. The study reveals that the Ground Domain Xing model can be considered as the relatively accurate GCHT model with low computational cost. One critical factor that differentiates these GCHT models is the ground surface boundary condition used. The study further explores the influence of thermal characteristics of underground building envelopes on annual energy consumption for five climate zones of China using the Ground Domain Xing model. The results show that the better thermal performance of underground building envelopes may increase the annual energy consumption in different climate regions.