Le condizioni di comfort termico nelle aree refrigerate dei supermarket

Despite the increasing spread of hypermarkets at the expense of small trade retailing, the characterization of thermal comfort conditions of these spaces (which absorb about 3-4% of electricity) have been only scarcely investigated in the past years, and the few meaningful studies addressed to customers and staff have been carried out in Northern Europe. In this paper an investigation about local and thermal comfort conditions for customers and staff of refrigerated areas in a point of sale placed in Southern Italy will be discussed. Results from microclimatic surveys seem to demonstrate that thermal comfort conditions for staff are generally consistent with UNI EN ISO 7730 requirements. To the contrary, the thermal sensation levels predicted for customers are generally turned towards the cold (PMV<0) both in autumn and summer seasons, where in some situations, as near vertical open cabinets, PMV values are even less than -2. Moreover, in very few cases thermal comfort conditions are acceptable. The analysis of the local discomfort has generally shown a very low floor temperature and a meaningful cold air stratification resulting in vertical air temperature difference even of 8-9 °C with highest percentage of dissatisfied. In summer, due to the relatively low air temperature values combined with low clothing thermal insulation levels, the implementation of the IREQ stress index revealed cold stress conditions in five areas (dairy products, cured meats, yoghurt, fish and vegetables) during the summer. To the contrary, in autumn, critical positions are only 3 (dairy products, butchery department and vegetables). Results from this investigation will be integrated with further studies devoted to the effects of the presence of doors on the cabinets and subjective/energy issues of the thermo-hygrometric assessment.