Jess McDiarmid
Northern News Services
Published Wednesday, January 23, 2008
YELLOWKNIFE - City council has unanimously accepted a recommendation allowing Giant Mine to be used as a test site for a residential fire suppressant.
It's a move that could have far-reaching implications for areas without readily accessible water such as Old Town.
Following this Latham Island fire in June 2007, then-fire chief Reid Douglas began looking at alternatives for fire suppression in areas like Old Town and Kam Lake that don't have ready access to piped water. - NNSL file photo |
On Monday, council gave the O.K. for the National Research Council to test a residential sprinkler system that uses compressed air foam instead of water in an abandoned house at the mine town site. It's designed for use in communities that lack piped water supplies, as many do in the North.
"This potentially provides improved fire protection for our residents who find themselves in that situation," said Coun. David Wind at the meeting. "I want to applaud administration for taking this initiative."
Compressed air foam, also called CAF, has been used in fighting fires for decades. Research into using it in sprinkler systems has been ongoing for more than 10 years but actual testing of the residential system began in 2005 as a joint project between the NRC and the Canada Housing and Mortgage Corporation (CMHC).
According to the CMHC, instances of fires in the North are eight times greater than the national average. Yellowknife became involved in the project following the Latham Island fire in June last year when a blaze destroyed a duplex on Morrison Drive in Old Town. According to city documents, firefighters' failure to put out the fire before it gutted the building was partly attributed to a lack of water supply.
Then-fire chief Douglas met with the NRC last fall to discuss compressed air foam and possibilities of its use in sprinkler systems for the city.
George Crampton, a senior technical officer with the NRC, said the initial systems would likely cost about $50,000 -- too expensive to be feasible for single-family homes but possible for multi-unit dwellings and public structures. And as technology becomes more available, the cost of a system would decrease.
Neither public safety director Dennis Marchiori nor acting fire chief Darcy Hernblad returned messages asking for comment on the system's potential for use in Yellowknife.
Crampton said researchers have been trying to land a house in the North for about two years to test how the foam works in cold conditions.
Although CAF has been used in fighting fires since the 1940s, it took years of research starting in 1993 to design a sprinkler system that is compatible with the foam.
Twelve years later, technicians in the national fire research program at the NRC constructed an average-sized room at its Almonte, Ont., burn testing facility and filled it with standard furniture and items that would be found in a house. They installed water and CAF sprinkler systems in order to compare the two.
And they lit it on fire.
They were surprised with the results, said Crampton.
"The test system actually proved to be more promising than we'd thought," he said. "We didn't have one dud in all those test scenarios, which is unusual."
Water sprinkled for 10 minutes would extinguish the outside of a burning sofa, once it was turned off, foam inside the furniture would still be smouldering.
"Once the water application stops, the fire builds up again and breaks out," said Crampton. Within five minutes, flashover -- the most dangerous time of a fire, when an entire room combusts -- occurred.
In places where a fully-loaded fire department can be expected in a matter of minutes, it's enough, he said. But in the North, that's often not the case.
The CAF system, however, dropped seven to 10 cm of foam in 10 minutes, "blanketing" the fire. In a room with a smouldering couch left for hours, the fire never spread, nor did room temperature exceed 60 C, while 300 C is when flashover occurs. The fires eventually burned out. They also found that CAF was far more effective in putting out grease fires than water. Because the substance is carried through dry pipes, freezing is less of a concern.
Crampton said they hope to begin testing by April with the Yellowknife fire department on-scene to help.
A system could be available within the next couple years if tests go well, said Barry Craig, an architect and senior researcher at CMHC.
They're confident the system works but it needs further testing, particularly in cold climates.
He added that CAF cools fires more than water, and doesn't steam, so is safer for firefighters. It also reduces the amount of damage caused by eliminating water and the foam can be vacuumed up after a fire.
"The amount of damage is quite minimal," he said.
