How to Clean Your HVAC Return Vents

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Your central air and heating system (HVAC) is equipped with supply and return vents. While both types of vents could use some cleaning from time to time, you should pay special attention to the return vents.

Supply vents blow hot or cold air out, while return vents pull the air in for recycling into your heating and cooling system. If your supply vents are on the floor, stuff can fall into them, but when the system is running, they push air out, which tends to keep things like dust bunnies away. Return vents, on the other hand, suck air in when the system is running and tend to get a lot dustier a lot faster.
How to Find Your Return Vents
If you don’t already know which vents are the returns, there are some easy ways to find them:
Return vents are generally larger than supply vents. Return vents don’t have adjustable louvers like supply vents often do. You don’t want to block off or close them because they’re pulling in air, and they can’t do that if they’re blocked. They’re sometimes located in the ceiling but, typically, are near the floor.
Not sure if you’re looking at a return or supply vent? When your HVAC system turns on, place a piece of paper by the vent. If the paper is sucked to the vent, it’s a return. Your house will have at least one return vent.
Why Should You Clean HVAC Return Vents?
Keeping your return vents clean helps your HVAC system run more efficiently, but there’s more to it than that. Clean return vents reduce the allergens in your home and keep the furnace filter cleaner, longer (so it can trap more dust and allergens).
Cleaning Return Vents
So, how do you clean those returns, and how often should you do it? Here’s a breakdown of what you should do and when you should do it.
Things to Do Monthly
Every month there are some things you can do to help keep your HVAC system running smoothly:
Change the Filter: In larger homes, the filter is typically located at the furnace itself. In smaller homes and apartments with only one large return, it’s often located there for easy access. The filter should be changed monthly when your HVAC system is in use. If a filter doesn’t have a place to write the date on it, put it on your calendar, so you’ll remember to change it when it’s time. Clean Out the Vents: Turn off your heat or A/C and cover furniture if your vents are in the ceiling. Vacuum your vents with a dust attachment, and then use a microfiber duster to loosen anything missed by the vacuum. Avoid using water and cleaning products, as they smear the dust around and turn it into a paste. What to Do the Rest of the Year
There are some things you can do less often to keep your return vents clean. Aside from the filters and basic vacuuming, twice a year, you can do an extra deep clean, including:
Cleaning the Vent Covers: Again, turn off the heat or A/C. Completely remove the vent covers and wash them in the sink in hot, soapy water. Be sure to use a microfiber cloth and only soak them for a short time. Also, don’t rub too hard, or the paint might start to come off. Removing Oil From Vent Covers: If you burn a lot of candles or have vents in the kitchen, you’ll need to remove grease during your deep clean. Rubbing alcohol cuts grease quickly and doesn’t require a lot of rubbing.
If the intake covers don’t fit in the sink, take them outside to clean them or use your bathtub—put an old towel down in the tub first, though, to protect it from being scratched by the metal edges of the vents. No matter where you wash them, be sure to dry the vent covers completely before reattaching them.