Article by Ryan Sharkey – Fire Alarm Installation Expert
On November 21, 1980 one of the nation’s worst fires occurred at the MGM Grand Hotel in Las Vegas, NV. The fire has been studied and investigated thoroughly and as a result many policy and regulation changes have occurred.
In that particular fire there were 87 casualties. What’s interesting is that only 18 of those fatalities occurred on the 1st Floor, where the fire started and was predominantly located. The others were in the upper half of the building, primarily the 16th-24th floors with smoke inhalation being the main cause of death.
There are many topics to discuss as a result of this terrible incident (such as automatic fire sprinkler requirements, ground-faults, notification appliances, fire/smoke dampers, etc.) but I’d like to focus on Smoke Control (or lack thereof), and the importance of Stairwell Pressurization.
Stairwell Pressurization uses mechanical fans to force air into egress stairwells upon fire alarm activation to create a positive pressure. That positive pressure in the stairwell, when calculated correctly, uses simple physics to keep the stairwell clear of smoke and fire. Particles always flow from high pressure to low pressure meaning if the stairwell maintains a higher pressure than a particular floor when the stairwell door is opened, particles will transfer from the stairwell to that particular floor. More importantly, smoke and fire will not transfer in to the stairwell from that particular floor.
Similar to Stop, Drop, & Roll, it has been drilled into our heads to take the stairs in the event of a fire. Stairwells become the primary, and sometimes only, means of egress from a building during an incident. Keeping stairwells clear is vital to the safety of building occupants. Not only does it help limit the spread of dangerous heat, smoke, and flames throughout the building, it helps occupants safely exit the building, and it assists firefighters coming UP the stairs to battle the fire.
In 1980, the MGM Grand did not have a stairwell pressurization system allowing smoke and heat to travel up the stairwells like chimneys, impeding the egress of many occupants of the upper floors. Although there were many factors that led to the outcome, a stairwell pressurization system could have had a drastic impact in a positive way.
Does your stairwell utilize this pressurization method? Need help finding out?
For expert advice, call Oliver Fire Protection & Security at (610)277-1331 or email us at sales@oliverfps.com and we would be happy to help.