Boiler mishap sets off school alarms

Glacier High School students evacuated the building Tuesday morning after exhaust fumes from the school's biomass boiler set off the smoke alarms.

The boiler gave off an impressive smoke plume, and Kalispell Fire Department responded when the alarms went off, but students and staff were not in danger, Kalispell Public Schools Director of Facilities and Transportation Chuck Cassidy said.

In the shoulder seasons, when the school doesn't need as much heat, the biomass boiler doesn't have to run constantly as it was designed to do, he said. The feeding mechanism is supposed to stop when the system is hot enough.

On Tuesday, the boiler was supposed to turn itself off because it didn't need more fuel, Cassidy said. Part of the system didn't receive the message, however, and the boiler's auger put more wood chips in the firebox.

"All of a sudden, it realized it had a lot of wood and not a lot of heat," he said.

Exhaust fumes and smoke filled the boiler. When on-site technicians opened the doors to check the system, some fumes escaped into the boiler room and set off the smoke alarms.

"I don't think this condition has happened before," Cassidy said. "We have never had it not want fuel and still give it fuel."

When operators first fired up the biomass boiler in October, Glacier High had "several fire department call-outs," he said. Technicians were still figuring out the boiler's venting and ducting systems, he explained.

The fire department was "called out three times before Thanksgiving when we were first starting the system out," Cassidy said. "We haven't had that problem for quite a while."

Despite a few bugs, which were to be expected during this first year of operation, the biomass boiler has benefited the school, he said.

"It has really reduced our natural gas consumption tremendously," he said.

At a school board meeting earlier this year, Cassidy told trustees that the biomass boiler started out burning more gas than technicians had expected.

"We are consuming more gas than anticipated and less chips than anticipated," he told the board. "It should be burning almost all the time, and the gas should only be coming on in an auxiliary manner."

The high gas consumption was largely due to working out the system's kinks during the fall, he said. After about the first month of operation, however, most of the boiler's bugs had been worked out and gas was needed less often.

In October, according to information from CTA Architects, the district spent $11,000 on natural gas at Glacier High. In December, the district spent $4,000.

From July 2007 until January 2008, Kalispell Public Schools spent about $42,000 to heat Glacier - $30,000 in natural gas and almost $12,000 in wood chips. That's about 17 cents per square foot.

In comparison, it cost the district more than $103,000 to heat Flathead High School during the same months in the 2006-2007 school year - about 36 cents per square foot.

The difference between the two schools would be even greater if Flathead had been built according to the same design standards used on Glacier, Cassidy told the board. Flathead doesn't have to bring in as much outside air as Glacier, he explained, which is where a significant portion of Glacier's heating costs come in.

At the end of its first year in operation, the boiler will have provided the district just under $100,000 in savings, Cassidy said. Over 30 years, the district expects to save about $7 million in heating costs with the biomass boiler.

"The bottom line on the dollar savings is the most important thing," he said.

The boiler also contributes to the local economy and the environment, he added. At least half of Glacier High's wood chips come from local slash piles that otherwise would just sit, unused, on the forest floor. Local company T.B. Gray supplies the chips.

According to early estimates, the boiler will use about 2,200 tons of wood chips each year. Glacier has burned 565 tons from Oct. 1 through March 20, Cassidy said.

Reporter Kristi Albertson may be reached at 758-4438 or by e-mail at kalbertson@dailyinterlake.com.