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How Can I Clean My AC Ducts?

Updated on July 6, 2022 by Joseph D. Nielson

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Home DIYer tidies up his HVAC unit after cleaning his home air ducts

At a minimum, your home should be a clean, clear, hospitable environment. You shouldn’t just feel safe in your home – you should feel refreshed, revitalized and happy. After all, our homes are meant to be sanctuaries that keep our families protected from the bustling, restless and polluted world outside.

But when was the last time you looked at your AC vents up close? Often, when HVAC systems go unaddressed for long periods, you’ll find all sorts of gunk and grime built up on the edges of your AC vents. And that gunk is just the tip of the iceberg – if that’s what the exterior looks like, can you imagine the state of the ducts themselves?

It’s normal to be worried about your AC ducts. It’s also normal to wonder, “what can I do to address the problem?” The first step is to research the best air quality monitors to ensure that the air in your home is clean. The next step is to take matters into your own hands.

You’ve come to the right place. In this Fresh Home Guide article, let’s explore everything related to cleaning your AC ducts: should you do it, should you call a professional, and how can you clean your air ducts using common household tools?

Should You Clean Your AC Ducts?

Is air duct cleaning worth it? The short answer is: yes.

The slightly longer answer involves contradictory opinions on the degree of efficacy for cleaning AC ducts, based on the various types of cleaning available. Back in 2019, The Washington Post published an investigation that called into question some air duct cleaning practices, but conceded that certain interventions (i.e., filter replacement, which we’ll discuss below) have an appreciably positive impact on air quality.

Other research shows that any type of air duct cleaning will have a positive impact on air quality and energy efficiency, citing the buildups of dust and mould in HVAC systems. According to the research, if those nasty micro-particles go unaddressed, home air quality can become poor – perhaps even dangerous.

Why Clean Your AC Ducts?

There are several reasons to clean your AC ducts. The primary reasons centre on indoor air quality, but some people clean their ducts for efficiency as well. Here are a few of the most commonly cited reasons for cleaning air ducts:

  • One or more of your home’s residents has asthma or allergies that are exacerbated by dust particles
  • You have pets in your home that contribute to overall dander and dust. This pet dander may find its way into your HVAC system.
  • Someone in the home smokes, contributing to indoor air pollution. If someone smokes indoors, you certainly want your HVAC system working in tip-top shape!
  • You worry about black mould, mildew or bacteria in your ducts affecting indoor air quality.
  • You want to prolong the functional lifespan of your HVAC system.
  • You want better energy efficiency in your HVAC system.
  • You’ve recently remodelled and are concerned about construction debris.

If you recognize yourself in one of the reasons above, you may consider cleaning your AC ducts. The next logical question to ask is: should I do it myself, or call in the experts? Let’s explore!

A woman doing yoga pauses after breathing in some dusty air

DIY versus Professional Duct Cleaning

Should you try DIY air duct cleaning? If you go through a professional operation, is duct cleaning a waste of money? These are all fantastic questions.

In many ways, the relative benefits of professional versus DIY duct cleaning are the same as any other household chore. You have to weigh your options according to personal preference, perceived personal ability, budget, and motivation. You also want to ensure you have the right tools on hand; for instance, you’ll want an air purifier and humidifier running if you’re going to be loosening mould and dust particles.

Here are a few scenarios to consider:

  • If money is no issue, and you prefer to have your ducts cleaned quickly by someone who’s done the job hundreds of times before, choose a professional air duct cleaning service.
  • If you’d rather not spend much money, and feel that your capability and know-how are high enough to execute a thorough AC duct cleaning, choose the DIY route.
  • If you are on the fence about your budget and abilities, we still recommend giving DIY duct cleaning a try. What is there to lose? If you do not feel that you’ve done an adequate job, then you can call in the experts.

Now, let’s say, for sake of argument, that you’ve chose the DIY route. What’s next? How can you clean your AC ducts without the help of a duct-cleaning professional? In the following sections, we’ll list a few ways to get the job done.

Roll up your sleeves, slip on a tight-fitting pollution mask, and let’s get started!

How to Clean Your AC Ducts

In this main section of our AC air duct article, we explore a few ways to clean your AC ducts. Before you start, let’s review a few pieces of equipment you’ll need to get the job done safely and methodically:

  • A tight-fitting mask, ideally one that filters fine particulates like mould spores, chemicals and pollution. This Popular Mechanics list of the best masks for woodworking and other DIY projects is a good place to start.
  • Gloves and goggles to avoid any irritants getting in your skin or eyes.
  • A screwdriver to remove vent coverings
  • A bristle brush or drill brush to loosen the stuck-on dust and grime
  • Paper towel to cover the supply vents as you loosened dust
  • A vacuum cleaner to conveniently remove the built-up materials
  • A microfiber cloth and paper towel to spot-clean the ducts
  • A new filter, which you will find by searching “furnace filter” or “air conditioning filter” at your local hardware store (these names are interchangeable).
  • Air purifiers for large rooms, which can help purify any lingering dust or mould after you finish.

The only item above that you will (likely) need to pre-order is the filter. Provided you have leftover N95 masks from COVID, chances are you have the rest of these items already lying around the home. That means you’re good to go – let’s get started!

Remove Vent Covers, Wash, and Cover Supply Vents

The first step is to remove the vent covers with a screwdriver. Submerge the vent covers in soapy water for a couple minutes and wipe them clean.

Next, prepare for cleaning by slipping paper towel over the supply vents. Lifted the unscrewed vent coverings and place a double-thick sheet of paper towel underneath, then put the covering back on to hold the paper in place. The goal here is to ensure that no loose dust kicks back into your home as you clean your vents.

Turn on Your Air Purifier and Loosen the Dust and Grime with a Brush

Check out our article on the best location to put an air purifier before you start this step.  Place your air purifier in a strategic location before loosening the dust, and wait for it to start purifying the air. How long does it take to work? Roughly 30-45 minutes.  

Get into your ducts with a long brush to loosen any stuck-on material. This step isn’t for the squeamish, as you might uncover some unexpected stuff: mould, bugs, and even animal droppings are not uncommon. All the more reason to run your air purifier in advance!

For extra power, we recommend using a drill brush. Use a regular attachment for areas around the opening, and a 30-inch flexible dryer brush attachment to get deep into your ducts.

A homeowner opens a door to find an industrial vacuum cleaner

Use a Vacuum Cleaner to Extract the Loosened Material

When you are finished loosening material with a brush, it’s time to extract all of that gunk and grime as efficiently as possible. The best tool for the job is a high-quality vacuum.

Working one supply vent at a time, remove the paper towels and stick the vacuum hose (or a flexible crevice tool) into the vent and turn the vacuum on its highest setting. Ensure that the “fan” setting is turned on for the HVAC/furnace as you vacuum.

Take your time with this step. Work methodically, moving from vent to vent. Most people try to rush this part of the process (since it can be time consuming), but now isn’t the time to cut corners. You’ve loosened all of the nasty bits; it’s imperative that you now ensure they are safely removed, otherwise your efforts will have the opposite effect!

Wipe Ducts with Microfibre Cloth and Paper Towel

With the bulk of the unwanted material loosened and vacuumed, you can turn your attention to spot-cleaning.

Start by taking a microfibre cloth to the interior duct walls, removing as much left-on material as possible. We like to follow up this step with an optional damp paper towel, which gets every last bit of stubborn grime from the ducts.

Change Your Filters

Even duct-cleaning skeptics can agree on this one: It’s essential to change your air filters for cleaner, healthier air.  

When you are finished cleaning your AC ducts, change your air filters. As mentioned, look for filters labeled “air conditioning filter” or “furnace filter.” It’s also a best practice to replace to include pleated air vent filters in each of the vent covers.

If in Doubt, Call a Professional Air Duct Cleaning Service

Unsure whether your efforts made an impact? Did you get stuck during one of the steps above? Or perhaps, while going through the process, did you find more grime and mould than you were comfortable tackling? In these cases, consider calling a professional air duct cleaning service.

You should be able to breathe a deep sigh of relief when you enter your home. It’s your sanctuary, your comfort zone. If your AC ducts are getting in the way of you breathing easy, roll up your sleeves and follow the tips above. As always, happy cleaning from Fresh Home Guide!

About Joseph D. Nielson

Former journalist and editor for various press groups, I now dedicate my time to reviewing products for the home and family life. When I get time to myself, I enjoy rock climbing, taking my dirt bike for a rip, and most importantly providing my family with the best home possible!