Ceiling fans as ventilation assisting devices in buildings : a critical review

Ceiling fans can reduce the cooling demand in an indoor area, improve thermal comfort, and save energy. Despite the numerous potential advantages of applying ceiling fans, the literature shows that the uptake is still limited, due in part to the lack of concise information on the ceiling fan's impacts and methods of evaluating its performance. A critical literature review on ceiling fans synthesises what we know regarding its implications and what is required in the future. Hence, this study aims to critically review the effects of ceiling fans on the indoor environment (i.e., airflow, thermal comfort, and Indoor Air Quality (IAQ)) and energy usage. The results show that thermal comfort and airflow are the most investigated parameters among different ceiling fan implications for indoor areas. In contrast, limited attention is given to IAQ. The findings also highlight a knowledge gap in hybrid ventilation, a combination of natural ventilation and ceiling fans, and its impacts on IAQ, vital during pandemics. The necessity for more studies on the effects of ceiling fans on energy savings for cooling purposes, which is a crucial issue due to the global energy crisis, is also argued. Additionally, this review identifies and outlines the applied methods to evaluate ceiling fan impacts on indoor areas and lays out the advantages and limitations concerning different scenarios. This paper contributes to the literature by providing a summary of available knowledge and future research directions. It also assists building designers with decision making on using ceiling fans individually and/or as a cooling assistant strategy.