• Outdoor heatwaves impact indoor spaces inconsistently across dwelling types. • Novel MSIHw method detects indoor heatwave start/end dates and durations. • Pilot temperature provides a representative basis for indoor heatwave detection. • Long-term risk analysis assesses the likelihood of exceeding recommended thresholds. • MSIHw results are validated against simulations with quantitative analysis. Both monitoring and simulation are essential for understanding the thermal behavior of buildings. When analyzing a wide variety of building types, thermal simulation prevails for obtaining rapid insights into thermal dynamics. While various thermal models can achieve this, most are reduced second-order models; such approximations may lead to inaccuracies, particularly when evaluating the impacts of climate change on residential indoor environments. Furthermore, weather data is often complex to analyze due to its numerous parameters, necessitating many inputs for performing building thermal simulations. This paper introduces the Modal Selection of Indoor Heatwaves (MSIHw) method, a novel method designed to identify indoor overheating periods without relying on conventional thermal simulations or monitoring. The method integrates the discrete modal method, a Simplified Equivalent Outdoor Temperature, and spectral analysis to construct a pilot temperature that tracks nighttime indoor temperature. The MSIHw method was applied to two French archetype houses and two Parisian apartments to conduct a thermal risk analysis spanning 39 years. This was achieved by evaluating the probability of the pilot temperature exceeding a specific nighttime threshold. Results were validated against dynamic thermal simulations, demonstrating 100% sensitivity and precision across 104 detected indoor heatwave events. For the selected projects, the MSIHw method successfully identified all core indoor overheating periods, providing to be reliable and computationally efficient indicator of multi-night indoor thermal risk.
Piñas et al. (Fri,) studied this question.