Substantial mould growth can be hidden within your home’s ductwork and inside the other components of your heating and cooling system. The debris accumulation within your ductwork can be perfect breeding ground for other indoor air contaminants, like bacteria, fungi, and dust mites.
This can lead to significant respiratory issues for asthma and allergy sufferers. Ductwork also can be infested with vermin, such as rodents and insects. It gives them an entry point to every room in your home.
According to the Canada Mortgage and Housing Association (CMHA):
A thorough duct cleaning done by a professional duct cleaner will remove dust and debris-pet
hair, paper clips, children’s toys and whatever else might collect down there. Ideally, the inside
surface will be shiny and bright after cleaning.