Are Your Vents Blowing Dust? Air Duct Cleaning

air duct cleaning

The vents in your home are supposed to keep clean, temperature-conditioned air circulating through the house. Air flows into the system through your intake register and, ideally, is stripped of all dust and allergens by your air filter. 

From there, the air flows through your heater or AC, being warmed or cooled as you see fit, then is blown out through the vents throughout the house. However, if your vents are blowing dust instead of clean conditioned air, something has gone wrong.

Unfortunately, many homes are currently in a condition where the HVAC system blows dust through the vents. This creates more airborne dust and actually increases the chances of dust and allergy sneezing at home.

Too much dust in the air can cause or worsen childhood asthma, and can cause breathing problems (especially at night) even for adults.

Are your vents clean or blowing dusty air? There's one surefire way to find out: The white sheet test.

Performing the White Sheet Test

The white sheet test is an incredibly simple way to discover just how much dust is blowing regularly through your home vents. First, start with a clean white sheet or pillowcase. This test won't damage your sheets at all so it's perfectly safe to use your good sheets.

Hang the sheet so that the air from one of the house vents blows through it. The goal here is to catch the dust that blows out of the vent and trap it on the surface of the sheet. I

n other words, you're turning your sheet into an interesting makeshift air filter. The best way to hang a sheet on the upper part of the wall or ceiling is with small nails. These can be easily removed and shouldn't damage the weave of your sheet when you're done.

Leave the sheet in place for one hour and then take it down. What can see with your eyes will tell you everything you need to know.

Comparing Your Results

The key to the white sheet test is comparing what the vent left behind with the rest of the still-white sheet. There is a small amount of dust in any vent, so you will very likely see a vent-shaped section of the sheet that has at least a thin layer of gray dust. However, some vents are dirtier and blow more dust than others.

The darkness (and grunginess) of the dust layered onto your sheet will tell you just how much dust is being blown through your vents. A great way to get a whole-house perspective is to perform this test in every room and compare the results.

This will show you which vents are dustiest and which rooms are likely more packed with dust and allergens than others.

Solutions to a Dusty Sheet

The good news is that all that dust coming out of your vents can be dealt with. There are actually several solutions to dusty vents and you may want to implement more than one of them.

Change the Air Filter

The first and easiest solution is simply to change your air filter. Most homeowners completely forget about the air filter behind their intake register, so it is in use for much longer than the recommended 6-12 months.

Choose a heavy-duty air filter like Dust Goblin for your replacement so that it will both last longer and block more dust from getting into your ventilation system.

Clean the Vents

Second, try cleaning the vents themselves. Air vents are also an ignored part of home maintenance and while your entire house might be spotless, the vents could still be grungy and covered in dust. That dust is then sprayed into the room when you turn on your heater or AC.

Clear the Ducts

Finally, if your vents are still blowing dust, consider having your air ducts cleaned. If the ducts themselves have filled with matted dust (which is a lot like dryer lint), then every gust of air will loosen and blow out more dust. Clean ducts combined with clean vents and a new air filter are the best way to make sure your home soon becomes almost completely dust-free.


The white sheet test is the number one at-home way to test if you need a new air filter or if your HVAC vent system needs to be cleaned. If you are having sneezing or breathing problems at home, or have noticed excessive dust on your surfaces, then this is the one sure-fire way to know if the problem is with ambient dust or dust blowing directly out of your vents.

For more information about how to stop dust in your house once and for all, contact us today!