Enhancing ventilated roof performance: A study on Maisotsenko indirect evaporative cooling for school buildings

Abstract

A ventilated roof consists of generating a series of ducts inside the roof of a building through the creation of openings near the rain gutters and on the ridge. Although in pitched roofs airflow is often buoyancy driven, for horizontal roofs or to enhance performance, forced convection becomes necessary. This study explores the use of a commercially available M-cycle evaporative cooler as a multifunctional solution for thermal management and ventilation in school buildings. By integrating the M-cycle with a ventilated roof, the study focuses on optimizing air renewal and cooling through the use of product air, while the working air, typically wasted, is used to ventilate the roof cavity. By employing an approach that combines psychrometric, analytical, and CFD models, it is demonstrated that, on a traditional roof configuration with cavity on top, the M-cycle can reduce solar gain by up to 68% when working air is used to ventilate the cavity. Furthermore, it is shown that the positioning of the ventilated cavity plays a crucial role, providing the best results when facing indoors. In such cases, it contributes to a solar gain reduction of up to 94%, leading to the development of a radiant cold surface that actively assists in cooling the room. These findings provide a first insight on a sustainable solution that can be applied beyond the specific case study, improving indoor climate control and reducing environmental impact.