Resumen de Geo-climatic potential for advanced natural ventilation comfort cooling approach in mid-rise office buildings in the north-western mediterranean
The objective of this investigation is to evaluate the geo-climatic potential for comfort cooling energy savings in mid-rise office buildings applying advanced natural ventilation (ANV) approach based on the stack-effect. The region of interest is the Mediterranean coastline of Catalonia with selected reference geographical locations—the cities of Barcelona, Terrassa and Tarragona. In the first part of this research is evaluated the climatic potential for natural ventilation (CPNV) for each location, as a theoretical level of availability of natural ventilation (NV) based on the model of adaptive thermal comfort. For a comparison of geo-climatic potentials in a wider regional context, additional reference locations are chosen along the Northern Mediterranean: Valencia, Marseille, Rome, Koper, Split, Athens and Nicosia. Generated results confirm that NV is feasible mainly from April to October while in July and August is considerably limited due to unfavourable climate conditions. The second part of the work examines cooling energy savings of the hypothetical mid-rise office-type building model “A”. Applied building performance simulations (BPS) demonstrates achieved total yearly cooling energy savings in the region of Catalonia between 22% and 51%. The same model positioned along the Northern Mediterranean displays cutting in yearly cooling energy loads in a wider range—from 6% to 51%.The following section evaluates levels of climate change vulnerability applying climate scenarios for the selected time-slices—the years 2050 and 2080. It is indicated that the potential of ANV will be reduced close to zero in July and August in 2080. However, the introduction of selected assisted cooling techniques demonstrates that this impact can be absorbed approximately back to the previously evaluated scale in the horizon of 2050. In the last part of the investigation, the new defined building model “B” displays an improvement of comfort cooling energy efficiency: selected NV techniques are merged in order to take advantage of lower nocturnal outdoor temperatures by passive means, whose potential is reflected on the decrease of active day-time cooling loads. For this purpose, the positioned model in Barcelona achieves the yearly reduction of cooling energy loads by 65% in present-time weather conditions. At the conclusion, under projected climate configurations for 2050 and 2080, in Barcelona Terrassa and Tarragona, the series of BPS displays a higher level of climate resilience and the overall reduction of cooling energy loads within 53% and 59%.
The key-contribution and the novelty of this research is in the performed series of experimental BPS of the building model “A” where are detected ANV system’s weaknesses as a result of estimated unfavourable climate effects. Relative to observed limited cooling performances, ANV is shifted from an autonomous comfort cooling concept to being a part of a complex ventilative system with specific day- and night-time cycles. Such a new established design approach based on dynamic heat storage is associated with an introduction of lower nocturnal and early morning outdoor air temperatures, as being less affected with future regional climate change. An achieved advantageous momentum in energy performances is categorized through strengths and opportunities. Thereby, the building model “B”, the outcome of this investigation, represents the climate responsive building form with an integrated climate sensitive comfort cooling system, which delivers a higher level of energy efficiency—seen as an acquired factor of resilience towards estimated climate change threats. Such a conceptualised hypothetical building prototype may prove to be a beneficial contributor in the current process of rapid deployment of renewable energy sources in the regional building sector, observed as well from the perspective of the ongoing European Union’s energy transition.
