Free-cooling potential in shopping mall buildings with plants equipped by dry-coolers boosted with evaporative pads

Shopping malls are often characterized by high internal thermal loads due to occupancy, lighting, electrical devices, and solar radiation entering through the large skylights. The aim of this study is the evaluation of the energy saving reachable adding a cooling evaporative pad upstream a dry cooler. In particular, two different cooling plant configurations has been investigated: a cooling plant with a chiller equipped with a dry cooler (C-DC), that can be used as condenser of refrigeration system or to work with free-cooling mode and the previous system equipped with an evaporative cooling pad upstream the dry cooler (C-E-DC) in order to enlarge the range of temperatures suitable for free cooling. A building model of a typical shopping mall and two cooling plant has been modeled by means of TRNSYS simulations carried out in several European cities. Simulation results show that the C-E-DC configuration allows a greater energy saving amount than C-DC configuration for all the cities considered. It can be noted that the locations with a hot or moderate climate have a higher reduction in chiller electrical consumptions. Further investigations will be carried out taking in to account more extensively the moisture content of the air for the different locations considered.