The drawbacks are almost always about who you hire
Air duct cleaning has a poor reputation in some circles, and it's earned — but the problem is the operators, not the service. The $49 "whole-house special" advertised on a door hanger is the source of nearly every horror story. These crews work fast, skip the equipment that actually matters, and sometimes do more harm than good.
When cleaning is done without continuous negative pressure, agitating the ducts simply relocates dust from inside the system into your living space. When a rushed technician forces a brush through fragile flex duct, they can tear it. And when there was never any real contamination to begin with, you've paid for a service that delivered nothing measurable.
How to avoid every one of them
Ask three questions before booking: Do you use truck-mounted or high-powered HEPA-filtered negative-pressure equipment? Do you follow NADCA standards? Will you show me before-and-after photos from inside the ducts? A legitimate contractor answers yes to all three without hesitation.
Avoid any company that quotes a flat "whole-house" price sight unseen, pressures you into add-ons on arrival, or can't show you a license. Proper duct cleaning takes two to four hours — not twenty minutes.
When duct cleaning genuinely helps
The EPA and NADCA agree that cleaning delivers the most value when there's actual contamination: after construction or renovation, visible mold growth, documented pest activity, or unexplained allergy and asthma symptoms. In Florida's humid climate, biological growth inside ductwork is common enough that periodic cleaning is reasonable preventive maintenance.