Resilient passive cooling strategies during heat waves: A quantitative assessment in different climates

The frequency and severity of extreme weather events like heat waves are rising, posing significant challenges for buildings and their cooling systems. To safeguard occupants from potentially hazardous indoor temperatures, buildings and their cooling systems must be designed and managed to withstand these conditions and thus be resilient. This study assessed via building simulations the resilience performance of selected individual passive cooling strategies for five different climates (ASHRAE climate zones 2A, 3A, 3B, 4A, and 6A) and three heatwave periods (historical, future mid-term and future long-term). Resilience performance was assessed with three criteria: heatwave impact (degree C h above a reference standard effective temperature), absorptivity rate (degree C/h), and recovery rate (degree C/h). Strategies such as solar shading, cool envelope materials, advanced glazing, and ventilative cooling could each reduce the heat wave impact and the absorptivity rates in all studied climates at different levels of efficiency. As the heat waves became more extreme, the performance declined at different rates depending on the climate. Some strategies were more suited to specific climates such as cool envelope materials in climate 2A. Most strategies could not speed up the recovery rates from the heat waves except for ventilative cooling in climate 3B. With careful design to maximize the benefits of favorable wind conditions, every climate could benefit from ventilative cooling strategies to speed up recovery from heat waves.