Quantifying Fenestration Effect on Thermal Comfort in Naturally Ventilated Classrooms

Abstract

This study seeks to evaluate thermal comfort in naturally ventilated classrooms to draw sustainable solutions that reduce the dramatic energy consumed in mechanically ventilated spaces. Passive ventilation scenarios are generated using alternations of openings on the windward and leeward sides to evaluate their effects on thermal comfort. Twenty-eight experiments were carried in Bahrain during winter inside an exposed classroom, the experiments were grouped into five scenarios namely: “single-inlet single-outlet” SISO, “single-inlet double-outlet” SIDO, “double-inlet single-outlet” DISO, “double-inlet double-outlet” DIDO and “single-side ventilation” SSV. The findings indicate that single-side ventilation did not offer comfort except at high airspeed, while comfort is attained by using cross-ventilation at ambient temperature between 21.8–26.8 °C. The temperature difference between monitored locations and the inlet is inversely proportional to the number of air changes per hour. The DISO scenario accomplishes the lowest temperature difference. Using cross-ventilation instead of single-side ventilation reduces the temperature differences between 0.5–2.5 °C and increases airspeed up to three folds. According to the measured findings, the DISO cross-ventilation scenario is a valid sustainable solution adaptable to climatic variation locally and beyond with zero-energy consumption and zero emissions.

Towards an Adaptation of Efficient Passive Design for Thermal Comfort Buildings

“…That represents the comparison between before and after optimization for the best case (circle shape), which shows that there is a significant difference between the temperature and air velocity in the different cities. From the same Figure 9a, we noticed a significant difference in the air temperature, especially in Alexandria city, where at points P10, P11, and P12, the temperature values are improved by decreasing about 3.1%, 3.2%, and 3.1%, respectively, where the 3.1% reduction is an acceptable value according to some references [95,96]. From Figure 9b, we inspect a high noticed achievement difference in measuring the air velocity that appeared in Alexandria city also, where at points P10, P11, and P12, the air velocity values are improved by increasing by about 466.7%, 122.2%, and 200%, respectively.…”