Project Overview

Officially inaugurated in March 2008 and designed to handle up to 30 million passengers per annum, Heathrow’s Terminal 5 is the new home base of British Airways’ fleet. As an essential part of the fire safety and building evacuation regulations, Heathrow’s state-of-the-art passenger terminals were to be equipped with a fully compliant Voice Alarm system capable of commanding an organised zoned evacuation of the general public in the event of an emergency.

Design Targets

All public areas of the buildings were to have a functional VA system in accordance with BS:5839 and BS:60849 and BAA’s Airport standard. A minimum of 0.50 Speech Transmission Index (STI) was required for these areas along with sufficiently high Sound Pressure Levels to overcome the background noise by at least 10dBA.

AMS Remit

Along with the main client and project architects, AMS successfully managed to incorporate a working electro-acoustic solution into the complex architecture of the building interior. The project presented many challenges to the design of the PA/VA system, mainly due to the heavy restrictions with regards to loudspeaker mounting locations in the spaces. In addition, certain areas of the building were expected to have high reverberation times, proving difficult to meet the specification requirements and offer design assurance.

Subjective results

Despite the reported generalised mayhem surrounding the airport terminal during the first weeks of opening, we were relieved to hear that the Public Address announcements sounded very clear and intelligible in the main areas of T5A. Further, we have since received positive feedback from the main client BAA about the good quality of the PA/VA system and the well controlled acoustics inside the building.