Evaluation of Evaporative Cooling and Mechanical/Natural Ventilation strategies for the design of air conditioning systems for classrooms, considering different climate change scenarios for Viçosa (MG)

Abstract

The design of air conditioning and ventilation systems aims to achieve thermal comfort and Indoor Air Quality (IAQ) with energy efficiency. Thermal comfort directly influences people's concentration and productivity indoors. In schools and universities, environments with densely occupied classrooms, this factor becomes important in the performance of academic activities. In these environments, it is important to maintain indoor temperatures and humidity within ranges that provide thermal comfort, and to promote air renewal in order to guarantee Indoor Air Quality. Considering the scenarios of climate change and global warming, with the tendency for average temperatures to rise and the growing need to save energy, promoting thermal comfort in these environments is becoming more challenging. In this context, this work analyzed how Evaporative Cooling (EC) and Mechanical/Natural Ventilation (MVN) techniques could be used as strategies to promote thermal comfort in a classroom in the city of Viçosa (MG). Based on a survey of the room's hourly thermal load, the capacities of EC and MVN systems to maintain the room's temperature between 22 and 35 ^oC for two relative humidity ranges, between 40% and 60%, and between 40% and 80%, were analyzed. The analysis was carried out for nine climate scenarios, one for today, four for 2050 and four for 2080. All future scenarios considered global warming at different levels. The results showed that EC, based on different climate scenario models, for the present and projected for the future, was able to keep the internal temperature of the room below 27 ^oC for the current climate scenario and below 31 ^oC for the most pessimistic climate scenario for 2050, in all situations keeping the internal relative humidity below 80%.