Dynamic thermal performance of pipe-embedded building envelope utilizing evaporative cooling water in the cooling season

Abstract

An active pipe-embedded building envelope, which is a kind of external wall with cooling pipes embedded, has been developed recently to reduce heat transfer through building envelopes in summer. However, the method presented in previous studies was not good enough to analyze the thermal performance of this kind of building envelope during the whole cooling season. In this paper, a comprehensive numerical model is employed to simulate the conjugated heat transfer through a pipe-embedded building envelope in the whole summer. The model has been validated by the experimental data and then employed to a case study. The performance of the novel envelope in different orientations in three typical cities in China is analyzed with the cooling water produced from evaporative cooling. The results show that the cooling pipes are effective in the three typical cities in China, especially in Beijing where the reduced heat gain in the cooling season reaches 17.4kWh per square meter of wall. And the reduction rates of overall electricity consumption are 51.9% and 58.9% in Shanghai and Guangzhou, respectively. The embedded pipes are more suitable for orientations with more sunshine such as the roof and west wall. The study will help develop a comprehensive understanding of the dynamic performance of pipe-embedded envelopes utilizing evaporative cooling.