How to Clean Air Ducts: 9 Steps and When It’s Best to Call a Pro

Before you start work, completely turn off your HVAC system. Depending on your system, you can do this from the thermostat or by switching off the circuit breaker that powers the HVAC system.

Use a screwdriver to remove the supply and return vent covers. The supply vents blow hot or cool air into a room, while the return vents remove the air from the room and send it back to the HVAC unit to be reheated or cooled.

Next, cover the supply vents with paper towels to prevent dust from blowing into the room while cleaning the ducts. Once you've finished cleaning a vent, replace the paper towel.

As you make your way around the vents in each room, uncover the one you’re cleaning while leaving the rest covered.

Once the supply vents are covered, grab the dryer vent brush and attach it to the cordless drill. Insert the brush into the vent and turn on the drill to clean inside the vent and loosen any stuck dirt or debris. Go slow and use caution to avoid damaging your ducts.

Put on your protective gear, including safety eyewear and an N-95 mask. Attach the vacuum extension hose to your shop vac and insert the hose into the vent opening as far as it will go. Turn on the vacuum and draw the hose toward you to remove the loosened debris inside the ducts.

Grab your microfiber cloth and dampen it. Use the damp cloth to wipe the inside of the air ducts as far as you can reach. Rinse the cloth each time you remove it from the vent, and repeat until the ducts are completely clean.

Wipe down the supply registers and return vents with your damp microfiber cloth. Use warm, soapy water to clean any stuck-on dirt and debris. Dry the registers and vents thoroughly before replacing them.

Once you’ve cleaned the ducts, replace your air filter. A clean air filter will help keep your ducts clean for longer. Ideally, you should replace your furnace filter every three months, though thinner ones must be replaced more frequently. Some types of filters, like media and HEPA filters, may last longer before needing to be replaced.

The final step is to turn your HVAC system back on via the thermostat or the circuit breaker panel. Check that everything works as it should, and call a pro if you have any concerns.