Ventilative Cooling in Shopping Centers' Retrofit: The Mercado Del Val Case Study

Nearly all retail locations use ventilation and cooling systems to ensure adequate air exchange for health reasons and indoor comfort temperatures. These systems can run for over 2,000 hours per year and we expect that average operating hours will continue to rise across Europe because of the continued trend towards longer opening hours and increased number of opening days. Shopping malls often enclose large open spaces and atria with high solar and internal gains that can drive ventilative cooling. This paper presents the ventilative cooling strategy proposed, analysed and implemented in one of the three demo cases of the project: Mercado del Val, the historic market of the city of Valladolid. Once we determined the climate suitability, we defined a ventilative cooling strategy that exploits openings in the façade and in the skylight to promote stack effect ventilation. Considering that indoor spaces of a shopping centre highly interacts among each other, a multizone based analysis of airflows is needed to evaluate the ventilative cooling strategy effectiveness and to assess potential energy savings. We sized openings area and location on the façade, taking into account design constraints, and we assessed their performances in terms of energy, thermal comfort and indoor air quality. Results show the potential cooling load reduction, with the achievement of acceptable thermal comfort due to the ventilative cooling in the shopping mall. The analysis performed supported the design decision process towards cost effective low energy shopping centre.