Assessing the thermal performance of a rooftop solar chimney attached to a single room

Abstract

The passive design approach can help to maintain comfortable thermal conditions in buildings and reduce energy consumption by minimizing the use of auxiliary mechanical or electromechanical air-conditioning systems. In particular, the implementation of solar chimneys for cooling increases energy efficiency in buildings located in warm climates by decreasing electricity bills and CO2 emissions. This paper presents a pseudo-transient thermal performance assessment of a ventilated room with and without the integration of a rooftop solar chimney for summer and winter conditions in Mérida (México). A global in-house numerical code based on a novel integration of both computational fluid dynamics and global energy balances was developed to solve the conjugate turbulent heat transfer in the ventilated room with the integrated solar chimney system. Numerical results were verified and validated, and they showed a good agreement with the benchmark solutions reported in the literature. The room with the integrated solar chimney improved the ventilation rates by 8–45% in summer and by 1.16–24.89% in winter. Both configurations under analysis fulfilled the requirements of 0.5–2.5 air changes per hour by the ASHRAE Standard 62.1. In general, we concluded that the integration of the solar chimney system showed higher ventilation rates, demonstrating its higher potential as a passive ventilation system in warm climates.