ronment. The front door was then opened and bedroom
windows were vented, creating a flow path from the
front door through the open bedroom window.
The bedroom door was then closed, blocking the
flow path. Less than 90 seconds after the front door
was opened, and before the bedroom windows were
vented, the temperature at the front door rose from
approximately 75°F to more than 550°F. At the same
time, the temperature in the living room (front and
rear), where the fire had started, almost doubled,
The Governors Island experiments showed that
adding ventilation or being in the exhaust flow path
of the fire reduced potential survival time. Importantly, it demonstrated the viability of closing the
door behind the firefighters once vent, enter, isolate,
and search (VEIS) operations have commenced. The
idea of firefighters entering a burning building and
closing the door behind them is both contrary to
traditional practice and counterintuitive. However,
the experiments definitively show that closing the
door interrupts the flow path, reducing oxygen in the
structure, lowering its temperature, and improving
both victim and firefighter survivability.
Another important and counterintuitive finding
in the Governors Island experiments relates to the
impact of venting on oxygen and carbon dioxide levels
in the open bedroom. Opening the front door and
the windows in the open and closed bedrooms led to
a decrease of oxygen in the air in the open bedroom
from 21 percent to eight percent. At the same time,
the carbon dioxide levels rose to nine percent of the air,
creating a highly hazardous environment for any occupants in that room. Closing the door to the bedroom
almost immediately began to reverse the effects. Within
two minutes, oxygen had risen to 16 percent of the air,
while carbon dioxide dropped to four percent.
The experiments also showed that interrupting
the outlet of a flow path can help slow a fire. In one
experiment, the front door was closed after the basement reached flashover. This interrupted the flow
path that had run from an open basement window
and Bilco door to the previously open front door.
While opening the front door led to flashover in several areas of the home, closing the door reduced room
temperatures by as much as 70 percent.
MORE TO DO
If we are truly concerned about the victim, there
are many more components we need to look at and
adopt. Does your department promote residential
sprinklers? Does your department promote Close
Before You Doze? Are you altering your search techniques to be more efficient? Are you applying water
in the quickest manner possible, regardless of if that is
from the interior or exterior?
Remember, the fire does not know where the water is
coming from! If it comes in the window or down the
hall, the temperatures will be reduced. If we promote
keeping interior doors closed and we promote getting
water on the fire in the quickest manner possible, we
will lower temperatures and decrease gas concentra-
tions—increasing the chance of survival.
Underwriters Laboratories, “Interrupting the Flow Path,” New
Science Fire Safety Article, http://newscience.ul.com/wp-content/
P.J. Norwood is a deputy chief training officer for the East Haven
(CT) Fire Department and has served four years with the CT Army
National Guard. He is a FDIC classroom, workshop, and H.O. T.
instructor; Fire Engineering advisory board member; and Fire Engineering book and video author and served on the ULFSRI technical
panel for the Study of Residential Attic Fire Mitigation Tactics and
Exterior Fire Spread Hazards on Fire Fighter Safety. Norwood is certified to the instructor II, officer III, fire marshal, and paramedic level.
He has lectured across the United States as well and overseas.
Sean Gray is a 24-year veteran of the fire service and is a
lieutenant with Cobb County (GA) Fire and Emergency Services.
He has been a member of multiple technical panels involving
firefighter safety research and is an appointed member of the UL
Firefighter Safety Research Institute Advisory Board. Gray is an
NFPA committee member for fire hose and fire service training
facilities. He recently coauthored a Fire Engineering DVD and book,
The Evolving FireGround. Gray has also been published in multiple
fire service magazines, is an FDIC H.O. T. lead instructor, runs the
Web site stopbelievingstartknowing.com, and delivers evidence-based tactics training courses across the United States. He has a
bachelor’s degree in fire safety engineering and is working toward
furthering his education.
Firefighter door control.