Influence of greenery configuration on summer thermal environment of outdoor recreational space in elderly care centers

Greenery can improve the outdoor thermal environment in elderly care centers during heat wave in summer. However, it lacks quantitative results and rules. This study investigated the summer outdoor thermal environment of four representative elderly care centers in Tianjin to establish the thermal demand of seniors. The different thermal effects of greenery types (GTs) were revealed in elderly care centers. To improve the quality of the outdoor recreational space, this study utilized numerical simulation to quantitatively establish the influence of tree-shrub coverage rate (TSCR) on the thermal comfort of seniors. The results showed that the thermal neutral physiologically equivalent temperature (PET) of elderly people was 27.0 degrees C in summer, and the thermal acceptance range of PET was 23.6-36.8 degrees C. Shrubs overall could significantly increase the tree's ability to improve the outdoor thermal environment. Furthermore, this study proposed different TSCR strategies. TSCR of the elderly care center should be greater than 31.5% to obtain great thermal acceptance for the elderly in summer; when the TSCR of the elderly care center could not reach 31.5% due to the reality, TSCR = 10.0% was the efficient strategy to improve outdoor thermal comfort. This research provided a scientific reference for the greenery configuration plan of elderly care centers in summer.