Night Ventilation as a Key Strategy for Enhancing HVAC Energy Efficiency in Educational Buildings: A Case Study of Energy Savings

Abstract

Educational buildings frequently face issues with overheating and high energy consumption associated with HVAC systems, amid rising global temperatures and increasing demands for thermal comfort. Night Ventilation (NV) has been recognized as an effective passive or semi-passive cooling technique that utilizes cooler outdoor air to discharge the building's thermal mass during the night, thereby creating a 'cool reservoir' for the following day. This article presents a case study on the implementation of night ventilation strategies in an educational building, aiming to evaluate energy efficiency and the impact on thermal comfort. The study analyzes the interaction between night ventilation rates, building thermal inertia, and the energy consumption of HVAC equipment during occupancy periods. The results demonstrate that an optimized night ventilation strategy can significantly reduce peak cooling loads and the number of thermal discomfort hours. Furthermore, the paper explores the economic cost-benefit ratio by comparing the energy consumption of fans during the night with the savings generated by the reduced use of HVAC systems during the day. The study emphasizes that, although night ventilation cannot always independently ensure full thermal comfort, its integration as part of a hybrid cooling system is a feasible and energy-efficient solution for educational buildings.