San Francisco Federal Building - California (USA)
Rendering of the building.
Schematic representation of the aperture modes. Each floor of the building is divided into two symmetrical sides. The figures show one half of one floor. The black square in the center of the figures is an elevator/service core that creates an obstruction to cross-ventilation airflow.
Predicted comfort temperature and airflow direction for a sequence of warm days (all temperatures in ºC). The gray squares labeled NW-WW signal cross-ventilation airflow entering the building in the NW bay and exiting in the SE bay.
Side view of the velocity field (m/s) in the NW and SW wings, with all operable windows open. The upper figure shows an area of the floor plan where the air can flow over the meeting rooms. The lower figure shows the effects of the service core obstruction, increasing the recirculation flow on the NW side.
Simulation of the final design for the user window flow deflector.
Variation of Ach/h with outside wind speed.
Work Performed
Design of the natural cross-ventilation system: airflow analysis, definition of the window geometry, opening area.
Definition of the building management system control rules.
Relevant Details
Tall buildings such as the new San Francisco Federal building present new challenges to natural ventilation design and energy efficiency.
In this building, wind-driven cross ventilation will be used in most of the floor plan in floors 6-18. The building volume that is cross-ventilated measures approximately: 107x19x52 m, starting at an elevation of 20 m.
The success of the natural indoor climate control system in this building will affect the working environment of a large number of people and may lead to the increased use of natural ventilation in office buildings.
Innovative designs, such as this building, greatly benefit from engineering analysis using state of the art computer simulation.
Detailed analysis of the ventilation performance of this building allowed for fine tuning of the design and gave increased confidence in the building performance, by providing detailed predictions of the cross-ventilation airflow pattern, the maximum velocities in the occupied volume of the workspace, and the ventilation efficiency and ventilation flow rates for variable wind conditions.
The configuration of the ventilation apertures in the façade, the office furniture design and the building management system control rules were tuned as a consequence of this study.
The control of the operable windows is a crucial feature of the design. EnergyPlus coupled with a control routine was used to calculate the effects of different control strategies and to design the control modes for the building.
Project Data
Architecture: MORPHOSIS
Engineering: Arup LA