What duct cleaning does and does not fix

Duct cleaning has a reputation problem, and it was earned. The category has enough operators promising health outcomes and enough three-figure coupons that turn into four-figure invoices at the door that a careful homeowner is right to be suspicious.

So here is the honest division, from a company that only does cleaning and does not sell equipment.

A fixed cleaning interval, quoted as though it applied to every house. Interval depends on the house, the occupants and what has happened in it, and anyone who gives you a number before asking about those is reciting a script.

A price advertised per vent that no house ever ends up paying, or a headline figure that grows once somebody is standing in your hallway. The way to avoid this is to get the number after the system has been counted, not before.

A health outcome. "Improves indoor air quality" sits close to a claim that cannot be supported for a specific house. Removing dust from ducts is a real thing to do. Curing a condition is not something a cleaning company can promise.

Chemical treatments and fogging added on the day. Ask what it is, ask why, and be comfortable saying no to something that was not in the quote.

There is usually a reason, and it is usually obvious: you have just moved into a house someone else lived in, there has been building work, surfaces go grey again days after cleaning, or you take a register off and find the lip packed.

If none of those is true and the system was done recently, you probably do not need it yet. A company willing to tell you that is the one worth calling when you do.