An experimental investigation on the passive ventilation and cooling performance of an integrated solar chimney and earth–air heat exchanger

Earth–air heat exchangers (EAHEs) and solar chimneys (SCs) can be used to improve indoor air quality and thermal comfort, and reduce the energy consumption of buildings. The ventilation and cooling performance of an SC integrated with an EAHE system (SCEAHE) on a typical sunny summer day is investigated herein, using a full-scale experimental test rig. The SC provides the driving force required to draw airflow through the EAHE pipe, and the air is cooled by the surrounding soil. The experimental results indicate that the buoyant driving force induced by the SC can drive the EAHE during the daytime. The maximum airflow rate achieved during the day was 252 m³/h. Furthermore, an airflow rate of 50–70 m³/h was achieved when the solar radiation intensity was low or zero due to the building thermal mass. Therefore, the combined effects of the building thermal mass and the SC provided 24 h of natural ventilation. The maximum reduction in the temperature of the outlet air compared to that of the inlet air was 12.5 °C. The maximum total cooling capacity, sensible cooling capacity, and latent cooling capacity of the EAHE were approximately 1398.0 W, 892.0 W, and 611.7 W, respectively.