Hotter and Faster: How to Fight a Modern Fire Underwriters Laboratories New York firemen tested the efficacy of immediately applying water directly to the source of the fire in an experiment this week. The New York Fire Department is experimenting with new techniques better-suited to fighting the fires of modern households. For generations, firefighters" first priority on arriving at a burning home was to "ventilate" the house - opening the roof and smashing the upper windows to let smoke escape. They had, on average, 17 minutes to get anyone inside out of the building before they succumbed to smoke inhalation. But modern construction and furnishing materials are changing the game for rescuers. In today's fires, the synthetic materials used in walls and furniture burn hotter and faster, leaving firemen with only four or five minutes of rescue time. Today's firefighters need to fight much faster - and update their strategy. To that end, the New York City Fire Department - the largest in the U.S. with more than 10,000 firefighters - is taking a new approach to figuring out fires: setting a bunch of buildings alight to find out what happens. Their findings may lead the way for fire departments across the nation to re-vamp their practices. Just 800 yards off Manhattan lies Governors Island - a 172-acre teardrop of land that hosts a scattering of historic buildings and a derelict Coast Guard station, currently being redeveloped as a recreational area. To test their suspicions, the FDNY took 20 old row houses that had been slated for demolition, stocked them with modern furniture bought from hotel liquidators, then set fire to each one in a series of controlled experiments. The buildings, previously used as Coast Guard dormitories, were built in the 1980s - just old enough to contain some of the synthetic materials in their construction that fire experts hoped to study. "There's an evolution going on with these types of fires," says John Drengenberg, director of consumer affairs at Underwriters Laboratories, the consumer safety research firm working with the FDNY. Because synthetic fillings in cushions, pillows and mattresses burn much faster than old-fashioned, natural fillings like cotton and feathers, a modern house fire grows far more quickly - often consuming all the oxygen in a room by the time the fire crew arrives on the scene. When firefighters let in fresh air by ventilating a newer building, the infusion of oxygen just makes the fire grow even larger. The firefighting environment for firefighters has changed dramatically over the past several decades. The hazards have increased, the fuel loads have increased, the type of construction has changed. So it's a very different working environment for the firefighters," Dan Madrzykowski, a fire protection engineer for the National Institute of Standards and Technology, explained. NIST is funding the study with a $1.2 million federal grant. PHOTOS: High Park Wildfires Whip Through Colorado This modernization also upends the conventional wisdom of when to introduce water to the blaze. In the fires of forty years ago, smoke rose toward the ceiling, and firefighters were trained to make use of the crucial foot or two of breathable oxygen along the floor. Spraying water too soon on a room full of smoke would drive smoke toward the floor and eliminate that breathable zone that survivors needed. Modern furniture stuffing, however, gives off an acrid black smoke that fills the room from ceiling to floor. Spraying water directly onto the flames, researchers suspect, may cut down on this smoke and actually make a burning home survivable longer. Last week, a few hundred members of the FDNY and UL observers set fire to the Governors Island buildings - each equipped with over a hundred sensors tracking measures like temperature, pressure, and oxygen levels - and used different strategies to put them out. Here's a video of what happened on July 3: The screen is split into four simultaneous views: both sides of the basement, where the fire began, and the front and back of the house. The digital clock shows the time elapsed since the fire's ignition. In the first few minutes of the video, the fire - ignited by turning on an "electric match" left on a chair - leaps to the walls and spreads through the basement. Outside, the firemen stand by, delaying their response to simulate the time it would take to arrive on the scene. In the next clip, several minutes later, flames are blazing out of the back window while firefighters push a hose through the front. The camera closest to the blaze cuts out. Once the crew gets water on the fire, the blaze decreases (and survival conditions improve) right away. Finally, firemen bring a hose through the back basement window as the last plumes of smoke billow out of the building. MORE: Climate Change Plays a Role in Wildfires - But Not the Only One This trial confirmed scientists" expectations: that applying water right to the blaze instead of ventilating the building would make conditions safer and help them put out the fire faster. It's a finding could radically change the order of firefighters" procedures upon arriving on a scene. While scientists have spent months experimenting on dummy houses in controlled laboratory settings, this was their first chance to send real firefighters into actual burning houses in outdoor conditions. "Firefighters don't fight fires in labs where we normally do a lot of our research, so we're trying to bring the laboratory out to them," Madrzykowski explained. Here's an example of why these measurements matter: the air we normally breathe is 21 percent oxygen. In one experiment, firefighters ventilated one bedroom (by opening its door) but hosed down another (without ventilating it). In the bedroom where the door was opened, the oxygen level fell to a deadly 2 percent as it was consumed by the flames. In the bedroom where the door remained closed, oxygen only fell to 17 percent - a survivable level. For New York's Bravest - and the people they save - that number could make all the difference.