I could not find a discussion forum on this class. Anybody know where it is?
We’ll start our own.
Bathroom Ventilation Ducts & Fans
This article should be required reading for all new inspectors. Improper venting of bathroom fans is so common in my area of the country (Midwest) that I make sure that I can verify where every bathroom exhaust fan vent pipe exhausts from the building. If I can’t, it’s usually because the duct pipe is vented through a soffit vent, routed under insulation, so I state in my report that further investigation is required as all bathroom exhaust fans must duct completely through the building, preferably through the roof if possible. It is very common to see what appears to be bacterial growth on the roof sheathing directly above a bathroom fan which is exhausting through a soffit vent. The moist air is being pushed back into the attic through the soffit vent by wind, causing the moisture to accumulate on the sheathing creating the staining problem.
Central humidification systems are quite common in the Midwest due to our long heating seasons which produce dry air in the home. During my inspections I usually remove the maintenance covers and inspect the water element as well as other components of the unit. It very common to see that the water element has not been replaced recently and that it is almost completely plugged with mineral deposits rendering it ineffective. I liked that the article discussed the potential bacterial growth hazards associated with the introduction of excessive amounts of moisture in the HVAC ductwork. I usually advise my clients about these hazards and always remind them to have the unit properly serviced on a regular basis.