- Author
- Proulx, G. | Tiller, D. | Kyle, B. | Creak, J.
- Title
- Assessment of Photoluminescent Material During Office Occupant Evacuation.
- Coporate
- National Research Council of Canada, Ottawa, Ontario
- Report
- Internal Report 774; IRC-IR-774, April 1999, 52 p.
- Keywords
- evacuation | office buildings | occupants | people movement | lighting equipment | fire safety | fire alarm systems | stairwells | sound (noise)
- Abstract
- A field study was conducted to assess the potential use of photoluminescent material (PLM) as a safety wayguidance system to support office occupant evacuation. The three research partners, the National Research Council of Canada, Public Works and Government Services Canada, and JALITE PLC, worked closely together to conduct this research. The Jean-Talon highrise office building at Tunney's Pasture, in Ottawa, was selected for this study. An unannounced evacuation drill was carried out with approximately 500 occupants on three upper floors under emergency lighting conditions, Floor 10 had been equipped with PLM directional hanging signs while Floors 9 and 11 were untouched. The following experimental design was established for the four identical, windowless, stairwells of the building: one stairwell was equipped with PLM signs and wayguidance lines without any additional lighting during the evacuation; a second stairwell, also equipped with PLM signs and wayguidance lines had reduced emergency lighting at an average of 74 lux; a third stairwell had reduced emergency lighting, to 57 lux ; and the last stairwell was untouched with full lighting. Twenty cameras were used to gather behavioural and time data on the three floors studied and in the four stairwells. Infrared cameras were used in the two stairwells that had the PLM installation. A questionnaire was distributed to evacuees as they exited, to obtain their assessment of their evacuation, the PLM signs and wayguidance system. Results from the questionnaire show that the evacuees assessed the quality of the lighting in the two stairwells with reduced emergency lighting as very good or acceptable. There was no difference in the assessment of the stairwell with full lighting compared with the stairwells with reduced emergency lighting. The majority of evacuees (70%) who descended the PLM-equipped stairwell, assessed the lighting quality as very good or acceptable, a very positive assessment of the system. Video recordings provided a complete account of the movements of every occupant evacuated during the evacuation drill. The time to start the evacuation in this building was highly dependent upon the evacuation procedure, since the occupants were expected to wait to start by the exit door for voice communication messages. The average time taken by the first occupants to arrive at each stairwell was 1 min 12 s, which is longer than results obtained in other office buildings. The average time to start descending the stairwells was over 5 min after the sound of the fire alarm when the Evacuation Message was issued. Overall, the full evacuation lasted some 20 min. The most important finding is the speed of movement of a natural crowd descending the four stairwells under different lighting conditions. Results show that, irrespective of the lighting conditions tested, speeds of movement measured are comparable to mean speed obtained in previous studies of stairwells with full lighting. While the results indicate that the stairwell equipped only with the PLM safety wayguidance system had the slowest speed of movement of 0.57 m/s, this stairwell also had the largest crowd, the highest density and disruption due to the upward movement of 3 firefighters which sloweddown the descending occupants. The stairwell with full lighting was second slowest at 0.61 m/s; it was the second most crowded of the four stairwells. Evacuation in the two stairwells with reduced emergency lighting was faster with 0.70 m/s and 0.72 m/s for the one with PLM and reduced lighting. These stairwells had the fastest overall speed as well as the least amount of people and lowest density. Close examination of these results leads to the conclusion that the decrease in speed in the different stairwells is thus more related to the increase in crowding and the density of occupants than to the lighting conditions. This study's findings show the interesting potential of PLM signage to assist occupant evacuation. Such signage, properly installed, can address certain deficiencies in the traditional approach of emergency lighting associated with power failure or smoke-logging of high-mounted luminaires. In order to obtain the expected outcome though, it is essential to properly install the signs, material and wayguidance components. Setting up a PLM wayfinding system appears as a cost-effective addition to, or even a potential replacement for, traditional electrical emergency lighting, since it does not consume energy, requires no wiring, minimum maintenance, and is completely reliable provided it is installed in locations where sufficient activation is ensured from normal illumination maintained on the evacuation route. The occupants' behaviour, their speed of movement and their subjective appraisal of the material are all in concordance to indicate that PLM signs and safety wayguidance system could be a worthwhile addition improving occupant fire safety in office buildings.