How to Get Rid of Smell in HVAC Ducts

Unscrew the register mounted to the floor using a screwdriver. Lift the register and look at it. If the register shows signs of liquid staining it is likely that something may have be poured into the vent. Moisture combined with dirt often creates an opportunity for bad odors. Set aside the register for cleaning.

Shine a flashlight into the vent opening. In most cases the duct will go straight down for about 12 inches and then T-off into two or more directions horizontally. Wear rubber gloves and remove any pieces of debris, toys, paper, fabric or other materials you may find. The duct should be clean tin metal and nothing else.

Vacuum the duct immediately below the opening. Make sure your nozzle end is securely attached. Snake the vacuum hose into each horizontal duct as far as you can reach to suction material beyond your view. Repeat until no debris is visible. In new homes many builders forget to cover the vents and they can be full of building debris.

Spritz a hand-held mop head with a 50-50 mixture of distilled white vinegar and water. Run the mop into the horizontal ducts to the length of the mop handle. This will pick up additional dust and the vinegar will kill bacteria. Spritz around the immediate vent. Scrub with a scrub brush and wipe with rags until your tin ducts look clean. Be careful of hanging screw heads and sharp metal side edges.

Wash your duct cover at the kitchen sink using a scrub brush and vinegar/water mixture. Make sure the cover isn't dented, is clean, the paint is intact and the regulator lever is functional. If necessary, sand and paint the register cover using a spray paint in a well- ventilated or outside location. Allow the paint to dry before installing the cover. Hang a potpourri bag to the underside of the register cover. Repeat this process for all vents in the house.

Add scent to your room by hanging a potpourri bag to the underside of the register cover. Tie a potpourri fabric bag to the end vent of a register cover away from the regulator lever using a ribbon tied around the bag. This will allow air passing over the bag to flow scent into your room each time the furnace or air conditioner turns on. Repeat this process for all vents in the house.

Check all of your ducting for openings, loose tape, or evidence of damage at least twice yearly. Change your filters monthly or as suggested by the manufacturer.