Thermal Comfort Measurements in a Hybrid Ventilated Office Room

Global climatic warming trends are becoming more and more obvious. They are characterizedby longer and more intense heat wave periods as witnessed in extreme by the summers 2003and 2006. This situation asks for mechanical cooling applications in office buildings. Is itpossible to reach good indoor environmental conditions using hybrid ventilation strategiesonly? This question has been investigated by measurements in the Forum Chriesbach, a newlow energy office building located in Dbendorf, Switzerland. The ventilation concept of thisbuilding is based on an earth-to-air heat exchanger system for hygienic air supply during daytimeand a passive night cooling strategy by stack ventilation through window openings in thefaade and towards a large atrium with roof outlets. Outdoor and indoor climatic conditions aswell as internal heat loads have been measured in an office room over the summer heat waveperiod 2006. The measured data shows, that the hybrid ventilation system is able to hold theoperative room temperatures during the heat wave period 2006 in the acceptable comfortrange of 0.5 PMV and to meet the requested indoor air quality limits (CO2 < 1000 ppm). Itthus confirms the thermal simulation results made by the project design team.