Ventilative cooling strategies to reduce cooling and ventilation needs in shopping centres

Because of the customer need of best possible comfort condition and satisfaction, shopping centers are conditioned by means of basic HVAC systems, often without considering the potential of natural ventilation to contribute to air change rate, and to reduce the cooling demand. Mechanical ventilation systems are also preferred to natural ventilation because more controllable and reliable since they are not affected by the uncertainty of natural forces.
However, atriums or in general common areas within a shopping center can suite the ventilative cooling purpose. In fact, on one hand they present more relaxed ranges of interior conditions respect to retail zones and, on the other hand, they can exploit the airflow driven both by thermal buoyancy and by wind pressure because of the big volumes involved. The use of ventilative cooling strategies can be beneficial in reducing both cooling demand and electricity consumption for ventilation.
The paper investigates the feasibility of ventilative cooling strategies as retrofit opportunities in shopping centers. Ten shopping centers, representing the retail stock among Europe have been analyzed under two aspects. First, we evaluated, according to the climatic cooling potential, the feasibility of natural or hybrid ventilative cooling strategies depending on internal gains; secondly, we identified the most suitable ventilative cooling strategies according to the architectural features of each shopping center. Then combining the results of the two analysis, we identified the most suitable ventilative cooling strategies according to different internal load. As last step, we proved the beneficial effect of the ventilative cooling strategies proposed in one of the reference shopping center. By means of dynamic simulation, we verified their effectiveness in terms of cooling need and ventilation consumption reduction. The results shows a cooling demand reduction between 41% and 49% depending on the lighting gains. The electricity consumption for ventilation is as well, decreased or nullified depending on the ventilative cooling strategies, linked with the lighting internal gains values.