A methodology for the practical assessment of natural ventilation designs in industrial buildings with reference to the indoor thermal comfort.

The design of natural ventilation devices in industrial buildings is complicated by the nonlinear interaction between the air flow rate and the indoor air temperature. Designs are therefore usually based on relatively simple calculations of the areas of ventilation openings to provide a specified flow rate at a given indoor/outdoor air temperature difference. However, the practical performance testing required for acceptance of the ventilator design still remains a difficult and dubious task. Although detailed integrated simulation tools for naturally ventilated buildings have recently been unveiled, these tools are not yet accessible to practising building services engineers. In this paper a simplified methodology for the practical assessment of natural ventilation designs with reference to the thermal environment in industrial buildings is proposed and successfully applied. The methodology is based on continuous temperature measurements over a period of time combined with simplified predictions of indoor thermal parameters for extreme environmental conditions. In the development of the methodology there is a strong emphasis on its comprehensibility and ease of use by practising building services engineering consultants. Graphical representation of the results ensures easy interpretation of the data. A complete case study with measurements and simulations is presented to illustrate the  ethodology as it is applied to a casthouse building at a large aluminium smelter.