Snow inside air handling unit blamed for carbon monoxide detected in Ottawa high-rise building

The Ottawa Fire Services says firefighters responded to a call for a natural gas odour inside a building on Norman Street Monday night. (Jean Lalonde/Ottawa Fire Services)

Snow build up inside the air handling unit is being blamed for causing a carbon monoxide scare at residential building in Ottawa’s Little Italy.

The Ottawa Fire Services says 9-1-1 received a call from a resident of a building at 98 Norman Street at 6:24 p.m. Monday, reporting an odour of natural gas in the building.

When firefighters arrived on the scene, they began evacuating the structure from the ninth floor down to the first floor.

“Firefighters, along with members from our HazMat Team, detected readings of carbon monoxide (CO) throughout the structure with peak readings of 120 parts per million (PPM) at the roof where the air handling unit was,” officials said.

“The source was confirmed to be caused by snow build up inside the air handling unit affecting the proper operation and causing CO throughout the structure.”

• Firefighters respond to 80 calls for carbon monoxide following heavy snow in Ottawa

The air handling unit was shut down and firefighters ventilated the structure. Officials say the air quality was monitored and CO readings returned to 0 PPM before residents were allowed to return.

There are no reports of injuries.

Firefighters responded to 80 calls related to carbon monoxide and natural gas odours across Ottawa between Friday and Monday, with calls linked to snow-covered furnaces and hot water vents.

“The problem here is that the vents are often close to the ground and it’s critical that the furnaces are able to let their exhaust out,” Dan Kirvan, Chief of Special Operations with the Ottawa Fire Services, told CTV News Ottawa Monday afternoon.

“When there is snow really close or blocking them, CO comes back into the house.”

Ottawa received 69 cm of snow between Wednesday and Sunday.

The Ottawa Fire Services is reminding people to take time to remove snow covering hot water/furnace vents outside.