Ducts are the enclosed channels, usually hidden in ceilings or walls, that carry conditioned air from the AC unit to different rooms; vents are the visible grilles where that air enters or returns from each room.
Ducts: The Hidden Delivery System
Ductwork forms the network of channels connecting the AC unit to every room it serves, and it's almost entirely out of sight, running through ceiling voids, wall cavities or under floors. Because it's hidden, buildup or damage inside the ducts often goes unnoticed until it shows up as a symptom elsewhere, like reduced airflow or a musty smell.
Vents: The Visible Endpoints
Vents, sometimes called grilles or diffusers, are the visible openings in a ceiling or wall where conditioned air enters a room, or where return vents pull room air back into the system to be re-cooled. They're the only part of the duct system most people ever interact with directly, which is why problems are often blamed on the vent itself even when the real cause is further back in the ductwork.
Why the Distinction Matters for Maintenance
A dirty vent grille can usually be wiped clean in minutes, but that has little effect if the ductwork behind it is where the real buildup has accumulated. Understanding this distinction helps explain why surface cleaning of vents doesn't resolve persistent dust or odour issues that are actually coming from inside the duct system.
If this sounds like what's happening with your unit, our AC Duct Cleaning page covers exactly how we handle it, or you can message us directly for a same-day assessment.
Frequently Asked Questions
Can I clean AC ducts myself the way I clean vents?
Vent grilles can be wiped or vacuumed at home, but the ductwork itself requires professional equipment to clean safely and effectively.
Why does dust keep appearing at my vents if I clean them regularly?
This usually means the ductwork behind the vent has significant buildup that's continuously being pushed through, which vent cleaning alone doesn't address.
Are supply vents and return vents the same thing?
No — supply vents deliver conditioned air into a room, while return vents pull room air back to the system to be cooled again; both connect to the duct network but serve opposite functions.