Impact of climate change on building cooling potential of direct ventilation and evaporative cooling: A high resolution view for the Iberian Peninsula

The current study uses a new methodology where the assessment of building cooling demand savings is obtained through a redefined concept of the Climatic Cooling Potential (CCP). This concept allows for the direct estimation of energy savings in buildings by the use of different passive cooling systems at a large spatiotemporal scale. In this paper, we apply this method to assess the impact of climate change on the future potential of Direct Ventilation and Evaporative Cooling. To do so, a set of high resolution climate simulations for the Iberian Peninsula for present and future climate, performed using the Weather Research and Forecasting model (WRF), were used. Three passive cooling simulations were conducted: the first one employs the hindcast simulation where WRF is forced by the reanalysis ERA-Interim for the 1989–1999 period (hindcast); the second employs the EC-EARTH forced historical run ranging from 1970 to 2000 (historical) and the third also forced EC-EARTH but for 2070–2100 (future). An eleven-year period was extracted from the historical run and validated against the first, the hindcast. The similitude of the results provided confidence on the ability of the EC-EARTH forced runs to correctly simulate climate and thus allowing the assessment of the effect of climate change in the outcome of the passive systems and cooling demand savings in buildings. The results show that the CCP conserves its spatial heterogeneity for both historical and future, but presents lower values for the future due to the increase in temperatures. Nevertheless, this reduction is mostly below 20% over the entire Iberian Peninsula along the annual cycle, for both Direct Ventilation and Evaporative Cooling. This means that even in the context of a changing climate, these kind of systems can still offer valuable reductions on the cooling demand of buildings. Furthermore, most of the reductions in the CCP, caused by the increase in temperatures, can be surpassed by increasing the flow rate or can even be compensated by the increase in Cooling Demand as a consequence of the rising temperatures.