1) Introduction

There is currently little guidance within current Building Regulations or British Standards available to the design engineer or regulator relating to the design of a ventilation system to serve a loading bay or coach park based on realistic design criteria. Ventilation of enclosed car parks is covered in reasonable detail in BS7346: Part 7: 2006, but that document specifically excludes loading bays and coach parks from its scope. BS5588: Parts 5 and 10 provides limited guidance and BS9999 refers the reader back to BS7346: Part 7: 2006 which specifically excludes loading bays and coach parks from its scope as already mentioned above. Comprehensive guidance is still lacking. As with car parks, ventilation of loading bays and coach parks is usually recommended to control the build up of Carbon Monoxide and other gases during day to day operation and for the extract of smoke and hot gases in the event of fire. Guidance that is currently available suggests ventilating loading bays and coach parks at a similar air change rate to car parks, i.e. 6 air changes per hour for daily ventilation and 10 air changes for a fire condition. The areas in which such commercial vehicles are parked tend to be relatively large, however the rate of air change compared to the potential fire load may be inadequate. New materials used in the construction of commercial vehicles and the size and nature of the loads they carry have further increased the potential fire hazard. The use of sprinklers within loading bays and coach parks to control fire growth is considered essential. The objective of the ventilation system will be to provide improved access by the fire service to tackle the fire and to provide some degree of protection to the building structure. A correctly designed smoke extract system should aid the fire fighting process; no system shall worsen the conditions for access by the fire service. Guidance is also given on measures to protect occupants during evacuation in the event of fire. This document sets out to give guidance to the design of ventilation systems for loading bays, service yards and coach parks and lists the options available to the design engineer. This document should also be of assistance to the regulating authorities in assessing the suitability of systems submitted for their approval.