How To Clean Central Air Conditioner Vents And Ducts

Vents and ducts for central air condition systems inevitably get dirty and even gross. So you are wondering, how do you clean central air conditioner vents and ducts? In this post, we combine industry professional knowledge and up-to-date research to thoroughly answer your question.

Many folks prefer to hire out the cleaning processes for their central air conditioner vents and ducts. However, most homeowners have the wherewithal and materials to accomplish this task at home. To clean your ducts yourself, follow these steps:

  1. Loosen dust in all accessible ductwork
  2. Remove registers as you clean
  3. Wipe off vent covers
  4. Brush, vacuum, and clean accessible ductwork
  5. Replace registers
  6. Replace or clean air filter

Keep reading the rest of this post for details on how to clean your vents and ducts at home. These directions work for both heating and air conditioning ductwork. We also answer several questions related to this post's topic, including advice on how often to clean your ductwork.

A residential HVAC duct cleaning with a power brush, How To Clean Central Air Conditioner Vents And Ducts

Can I clean my AC ducts myself?

Many home cleaning companies and services offer duct cleaning. However, and as stated above, this is a job that most homeowners and renters can accomplish themselves. For ease, follow the directions outlined below.

The directions contained in this post are applicable to ductwork that is run both underfoot and overhead. However, ductwork that is run in the basement or crawlspace tends to get much dirtier because of the natural effects of gravity.

It is essential to the cleaning of ducts that you provide yourself with light to see. A good trick is to use a high-powered flashlight that you do not mind setting in the ducts to light your way as you clean.

Click here for a suitable flashlight for cleaning your ducts on Amazon.

As you do this step, it is smart to wear gloves and even breathing protection. If you notice pest waste or other hazardous materials, take extra caution during cleaning or, better yet, call a professional to clean the ducts for you.

1. Loosen dust in all accessible ductwork

This step is mostly applicable for homes with walk-in basements where the ductwork is easily accessible. It is also sometimes possible to reach ducts in crawl spaces and attics. However, the difficulty and discomfort of entering these spaces are usually not worth the effort.

Thermostat setting the temperature

To attempt to loosen the dirt within your ducts, first turn on your AC blower fan. On newer thermostats, there is a "fan" setting; you can choose to just turn on the fan. For older thermostats, you might have to turn to AC or heat on to get the fan going.

Once the fan is turned on, tap along your ducts to attempt to loosen any dust. This will help blow all of the dirt closer to the vents (also known as registers). Once closer to the registers, the dirt and dust are much easier to clean.

2. Remove registers as you clean

Often, the vent registers are screwed into the surface on which they are set. If this is the case, remove them with a screwdriver or power drill. Be sure to carefully set aside the fasteners for later reattachment. Other times, the registers are simply set into the flooring and can be removed by hand.

Click here for a multi-head screwdriver sold on Amazon. It is almost certain to have the head you'll need.

For the work of cleaning ducts, you want to be sure to clean both supply and return ducts. Generally, supply vents are smaller and more common, and return vents are larger but fewer.

3. Wipe off vents

As you remove the vents, take the time to thoroughly clean them. Sometimes, this is as simple as wiping them off with a wet rag. Other times, you might want to use a vacuum on the registers to clean off pet hair as well.

Opening up floor vent heater

For seriously grimy registers, you might need to use hot water and cleaning solutions. This can be done in the sink or outside at a hose. Either way, once you are done cleaning your vents, they should be clean as new.

3. Brush, vacuum, and clean accessible ductwork

Now comes the serious work of this project, cleaning out the actual ducts. As you know, ducts are cramped and difficult to access. Because of this, it is ok to just clean what you can reach. Fortunately, areas we can reach also tend to collect the most dirt and debris.

Click here for kneepads on Amazon.

To clean the ducts, use a combination of brushing, vacuuming, and wiping with rags and paper towels. For ducts on the floor, it might be worthwhile to wear kneepads or use a kneeling pad to make the work more comfortable. For ducts in the ceiling, be sure you are capable of safely using a ladder.


First, take your vacuum to the ducts. While a home vacuum with a hose will work, renting a high-powered vacuum will allow you to clean much more effectively and efficiently. Further, industrial vacuums usually come with longer hoses, which allow you to clean much deeper into your ducts.

Click here for a high-powered shop vac from Amazon.

For this first vacuum step, just try to get the easy to suck dirt and debris - we will be scrubbing in a later step. Take the hose and suck up as much as you possibly can. Also, be sure to stick the suction head deep into the ducts to get even the dirt you cannot see.


After the initial vacuum, it is time to take a brush to the dirt that did not suck up with the vacuum. This type of dirt is more common in older duct systems that have not been cleaned for a very long time. Oils stick the dirt to the walls and floor of the ducts.

Therefore, use a brush, like a clean toilet brush or other stiff brush, to dislodge the stuck-on grime. At this point, do not use any liquid cleaners and rely on the physical action of the brush alone.

Reach as deep into the ducts as you can. It might be worth attaching the brush to an extension or extendable pole in order to clean deeper into the ducts. Brush all surfaces that are dirty enough

Vacuum Again

After brushing, it is time to vacuum again. This time, you are trying to vacuum up any dirt that you dislodged in the brushing step. Further, if you have a brush head for your vacuum, this is a good time to spend some time brushing with that head as well.

Hopefully, this vacuum step will get almost all but the most persistent dirt and wetter stains.

Clean with Rag and Cleaner

Now it is time to clean with a rag, water, and cleaner. Usually, there will be some dirt that you just could not remove with the vacuum and the brush. For these tougher areas, use a rag and cleaner. Sometimes, you might want to use the cleaner with the brush as well.

Click here for an all-purpose cleaner from Amazon.

For the dirt removed, take it out of the ducts with your rag or with paper towels. As your rag becomes dirty, be sure to frequently wash it clean in a bucket full of water or a utility sink.

Take your time to get your ducts as clean as possible in this step since this is the last step in the actual cleaning process.

5. Replace registers

Once you have cleaned the ducts as far as you can reach, make sure to replace the vents/registers back where you found them and with the original fasteners.

6. Replace or clean air filter

It is essential to replace or clean your air filter after you finish cleaning your ducts. Often, air filters harbor a significant amount of dirt and hair. If you do not take the time to clean or replace these filters, you leave a lot of dirt in your freshly cleaned duct system.

How often should central air conditioning ducts be cleaned?

Generally, it is recommended that you clean your air conditioning ducts every three to five years. However, if you live in a very dusty place or have many pets who live in your house, you might want to up the frequency of your cleanings.

What happens if you don't clean your air ducts?

If you do not clean your air ducts, the air in your home may start to become unhealthy. Ducts can house pests, mold, and other potential lung irritants.

Will cleaning my air ducts make my house smell better?

If the ducts smell, then cleaning them will help your home smell better. Often, ducts harbor food particles, pest waste, and other organic materials that will begin to rot and release an odor. If this is the case, cleaning your ducts will help with in-home odor.

How much does it cost to clean HVAC ducts professionally?

In most cases, it costs between $450 to $1,000 to have your HVAC ducts professionally cleaned. This price depends on duct condition, size of the system, and local wages.

How often should you clean your AC filter?

You should clean your AC filter at least every two months or when your filter begins to get dirty. If you have disposable filters, also be sure to change them out every two months of regular AC use.

In Closing

In this post, we answered the question of how to clean AC central duct systems. These directions include all you need to accomplish this task at home. To conclude, we answered a few questions related to the topic of this post. Good luck!

Read these great HVAC Seer articles to learn more about central AC systems maintenance:

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