What to know
The honest inventory
- Skin cells and fabric fibres, which make up the bulk of household dust.
- Soil and grit tracked in from outside.
- Pet hair and dander, concentrated on the return side.
- Cooking residue, particularly near a kitchen return.
- Insulation fragments where runs pass through an attic or crawl space.
- Construction and drywall dust, which is fine, travels everywhere and stays for years.
- Occasionally vermin droppings or nesting material, which is a specific finding rather than a general one.
- Where surfaces have been damp, mould growth.
What that does and does not tell you
The EPA's own guidance is worth knowing here, because it is more cautious than most advertising: duct cleaning has never been shown to prevent health problems, and studies have not conclusively shown that particle levels in homes rise because of dirty ducts. What the EPA does list as reasons to consider cleaning are substantial visible mould growth inside the ducts, vermin infestation, and ducts so clogged that debris is actually being released into the room.
It also notes that much of the dirt in ductwork adheres to the duct surfaces rather than entering the living space, which is the part most advertising leaves out.
So why clean it at all
Because a system carrying a lot of material has less room to move air through, because construction debris has no business being there, and because the EPA's own list of reasons — visible mould, vermin, debris actually being released into rooms — describes real situations that turn up in real houses.
Those are specific, checkable reasons. They are a better basis for a decision than a general claim about your air.
What we will not tell you
We will not tell you what is growing in your ducts without testing, because we do not know. We will not tell you that cleaning will make anybody in the house feel better, because that has not been demonstrated and the federal guidance says so plainly.
What we will do is show you what is in there and let you decide.
Where to start
What is actually in your system is a question about your house, and it takes a look rather than a guess.
Our inspection is free, we will show you what we find, and if the honest answer is that nothing needs doing yet, that is what you will get told.