Decision tree analysis of thermal comfort in the courtyard of a senior residence in hot and humid climate

Abstract

With global population aging, Taiwan is expected to become a super-aged society by 2025. Senior citizens, who are more susceptible to heat stress, engage in activities in the outdoor spaces of senior homes; the risk of heat hazards for this group requires particular attention during hot and humid summers. This study simulated and analyzed thermal comfort in an outdoor garden of a senior residence and identified key factors affecting thermal comfort by using decision tree classification. Strategies for improving thermal comfort based on these factors were proposed. Simulation revealed that the modified garden design increased the surface area with physiological equivalent temperatures (PETs) of 34–38 °C at 2:00 p.m. from 30.6% to 45%, whereas the area with PETs of 38 °C or higher decreased by 14.3%. The surface area with PETs of 30–34 °C (slightly warm) at 4:00 p.m. increased to 54.1%, accounting for more than half the garden. The modifications improved overall thermal comfort and reduced climate-related risk considerably. These results can be referenced during the preliminary stages of outdoor space design to ensure thermal comfort.