Ventilation design for a bus station.

The paper presents the development of a ventilation scheme for a large bus station and passenger interchange in Bilbao, Spain. The main objective of the design was to ensure that pollution free conditions could be achieved within an enclosed waiting area that opened up on to, and was surrounded by, a semi-enclosed pick-up space, where there could be large number of buses with their engines running. Initial thoughts were to use natural ventilation, architectural and other constraints made this impossible so mechanical ventilation became necessary. The application of a multi-cell ventilation model to determine air movements within the whole station, including an assessment of the ability of the system to prevent exhaust fumes entering via open doors is described. This is followed by a discussion of the results of wind tunnel tests on a 1:400 scale model to determine pressure coefficients and likely pollutant levels in the semi - covered areas occupied by buses. The result of these studies was the presentation of the design scheme to the client, and we are looking forward t o his response which should be available by the time of the Conference.