![School Indoor Air Quality](https://upload.wikimedia.org/wikipedia/commons/5/5d/Pine_Bush_Elementary_School.jpg)
Problem: A northern Alberta school was experiencing a strong periodic sewer-like gas smell that made students and staff sick. An investigation of the air handling unit found the humidification drain line to be dirty with a similar odour. When the unit ran, odorous air was drawn from the drain line into the air unit and caused the school odour.
Solution: Replacing the drain line eliminated the sewer-like gas smell.