Numerical investigation of different cooling technologies during heatwaves in Catalan Mediterranean buildings

Abstract

The Mediterranean area is particularly affected by heatwaves, which are extremely critical for health and productivity of people inside the dwellings as well as for energy consumptions related to cooling demand. This study numerically investigated the resilience of different cooling technologies in the most common construction in Catalan building stock during present and future climatic conditions, heatwaves. The studied technologies include green roof, blinds, advanced windows, air conditioning and their combinations. Meteorological data of heatwaves for Barcelona city have been created for three time periods, Present, Mid Future and Long Future. They have been modelled using dynamical downscaled Regional Climate Models, climate projections based on IPCC scenarios. Resilience was assessed using indicators that consider the linear correlation between the grade of overheating inside a dwelling and the severity of outdoor conditions. Thermal comfort and survivability have been also investigated, evaluating sensations of building’s occupants related to indoor air temperature and relative humidity. The original building presented acceptable levels of resilience with a resilience index α below 1, while thermal comfort conditions resulted poor, especially during heatwaves, being for more than 60% of the time in Extreme Caution conditions or worst. The application of the different cooling technologies significantly helped in the improvement of resilience and survivability inside the dwelling. However, their performances reduced in the future scenarios, reaching more than 90% of the time under Extreme Caution conditions or worst. Air conditioning resulted the best solution for avoiding overheating, especially in heatwaves constraining it to a maximum of 1.8°C. Combinations of several passive measures resulted necessary for maintaining suitable conditions.