airflow rates

The new initiatives and regulations towards nearly zero energy buildings forces designers to exploit the cooling potential of the climate to reduce the overheating occurrence and to improve thermal comfort indoors. Climate analysis is particularly useful at early design stages to support decision making towards cost-effective passive cooling solution e.g. ventilative cooling.

This paper presents a study of the potential for the use of natural ventilation systems in Portuguese multi-family residential buildings under winter climatic conditions. The behaviour of various natural ventilation systems is tested in a standard residential dwelling, using the TRNSYS 15 and COMIS 3.1 software programs. This study leads to the conclusion that the use of hybrid ventilation systems can save a considerable amount of the energy normally spent on continuously operating mechanical ventilation systems.

The Spanish Technical Building Code is one of the three royal decrees that were approved in Spain as a consequence of the transposition of the European Directive on the energy performance of buildings (2002/91/EU, 2002). One basic document of the Technical Building Code deals with the limitations of building energy demands. Nowadays, due to the recast of the European Directive on the energy performance of buildings (2010/31/EU, 2010), a revision process of the current regulations has begun, starting with the Technical Building Code, with its first revision envisaged for 2012.

Although it has been used for many years in commercial buildings, the application of demand controlled ventilation in residences is limited. In this study we used occupant exposure to pollutants integrated over time (referred to as "dose") as the metric to evaluate the effectiveness and air quality implications of demand controlled ventilation in residences. We looked at air quality for two situations. The first is that typically used in ventilation standards: the exposure over a long term.