A guy named Dan Madrzykowski with the National Institute of Standards and Technology thinks that modern homes and buildings are not built the way they used to be. In terms of being eco-friendly and saving on the utility bills, modern structures are much better than what we lived in back in the 1950s and 1960s. In addition, the fuels (i.e., furniture, carpeting, electronics) that we have inside the buildings today are not the same as what we had back in great-grandma’s house.
Unfortunately, when these modern marvels catch fire they do not burn the way firefighters are trained to expect.
Madrzykowski, a fire protection engineer in NIST’s Fire Research Division, has spent five years burning down buildings to prove his point. First, computer models provided insight into fires where firefighters became casualties. Madrzykowski then found buildings slated for demolition and, working with local firefighters, recreated the original fires to validate the computer models by using gas burners with known heat release rates.
Every year, almost 100 firefighters die in the line of duty, and more than 80,000 firefighters are injured. Burns accounted for almost seven percent of firefighter fatalities and eight and a half percent of injuries.
Madrzykowski’s research indicated a solution as simple as firefighters closing the door behind them, either to isolate them from the hazard or to limit the flow of oxygen to the fire, slowing its growth.
Homes and buildings today are built using materials such as polyurethane foam, polyester fabrics and plastic furnishings. To control utility bills, we wrap our homes with insulation to keep out the cold air. When incinerated, these materials break down into their hydrocarbon constituents, filling these sealed interiors with toxic fumes.
Architectural tastes have changed the dynamics of fire fighting as well. Newer buildings have floor plans far more open than older homes. In the old days, a typical room might be as small as 12-foot by 12-foot due to limited spans then available in lumber.
Today, household trusses easily support two-story foyers so quick to fill with smoke and fire. These innovations in materials and design mean that arriving responders today confront flames far more intense than their predecessors regardless of an identical response time.
One of the actual fires that Madrzykowski bases his research on is the infamous 1999 Cherry Road fire that killed two Washington, D.C., firefighters. The fire, which involved a basement fire in a residential home, marked the first time that NIST used a computational fluid dynamics model to investigate a firefighter fatality.
“Due to the intense smoke, firefighters came in the front door not realizing that such a massive fire was getting ready to erupt in the basement as a result of the walkout basement doors on the rear being vented,” Madrzykowski said.
Intense heat traveled up the basement stairway to catch firefighters on the first floor. Ventilation in the basement caused the fire to flashover, going from floor to ceiling in a heartbeat. The intense heat exceeded the tolerance of the bunker gear worn by the firefighters. Two died and one escaped with burns over 65 percent of his body.
A coordinated attack flowing water into the basement doors after they were opened would have prevented the flashover. But firefighters are taught that such action might push the fire and make conditions worse.
“Experiments in the last five years show that this is not the case,” Madrzykowski said. “Early water is a very good thing.”
Likewise, firefighters are taught that living room fires require either an aggressive interior attack or a transitional attack where fire is fought from the outside, then inside. NIST research shows that an aggressive exterior attack is not only better for the firefighters but for occupants trapped inside.
As for interior attacks, research shows that closing doors to decrease the inlet and outlet of air keeps temperatures down until firefighters are in position to fight the fire.
Door control and exterior attack research has been adopted by New York, Los Angeles and other fire departments.
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