An air handling unit dispersed dangerous concentrations of carbon monoxide in the hallways of a residential building
September 30, 2021
Regulated industry sector: Gas - Natural gas system
An air handling unit created conditions which allowed high concentrations of CO to be distributed throughout common hallway areas of a building on two separate occurrences. After investigation, it was noticed that the ducting filters had become blocked. Also, there were unsealed gaps between the filters and the blowers. These conditions allowed the boilers in the mechanical room to produce high levels of CO which were then distributed by the air handling unit into the building.