Monitoring Results of a Naturally Ventilated and Passively Cooled Office Building in Frankfurt, Germany

Abstract

Ventilation, cooling and air-conditioning contribute significantly to the energy consumption of many existing office buildings, particularly when primary energy factors are taken into account. “Lean” building concepts however can diminish this energy consumption by natural ventilation and passive cooling strategies. Compared to fully air-conditioned buildings the resulting indoor temperatures float in a broader band during summer and might exceed the boundaries for thermal comfort for short periods. This paper presents the monitoring results of a naturally ventilated and passively cooled bank building in Germany and shows that, even during the very hot summer of 2003, the indoor climate could be held in an acceptable range by only passive means if the rooms were operated properly. The air quality was shown to be high with natural ventilation. Investigations on the night ventilation strategy revealed an incorrect implementation of design parameters in the building management system. Further optimization potential for nocturnal airflow was found by simulations based on recorded data. The low total primary energy consumption for heating, cooling, ventilation and lighting of 115 kWh m-2a-1 confirmed an excellent performance of the building. Monitoring proved to be a necessary and efficient way to optimize the building’s operation.