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How to Improve Basement Air Quality

Last updated May 16, 2022

This post may contain affiliate links.

Author avatar Danny Ashton

Danny as been writing about air purifiers for 10+ years. He is a major fan of home technology, which makes him the perfect person to test and evaluate products for HouseFresh

Basements are great for extra living space, but there is a downside. There is limited airflow, and it’s difficult to move out the stale basement air or regulate its temperature. What’s worse is that basements can sometimes smell musty or even attract mold. 

The good news is that you don’t need to live with bad smells or mold. There are many ways that you can improve the air quality in your basement, and that’s what we’ll be looking at in this article. 

The Main Issues Surrounding Air Quality in the Basement

To get a clear picture of the problems you’re dealing with in your basement, consider the main issues surrounding air quality in the basement: dampness, dust, and musty smells. 

Let’s go over each one in more detail so that you know what you might be up against. Don’t worry! We’ll also go over how to improve the air quality in your basement so that you can eliminate these problems. 


Moisture and dampness are the biggest culprits when it comes to poor air quality in basements. A moist environment can cause fungi to grow, which can rot flooring or damage your walls. Dampness can also lead to health issues for inhabitants of the house.

Generally, dampness occurs in basements because water vapor enters from outside as a result of rain or ground seepage. Most houses are built with a drain tile system that prevents groundwater from flooding the basement, but this system does not always prevent vapors from entering.

  • Pro tip: If you want to keep your basement dry, making sure that there is proper ventilation is key. Ventilation will allow excess moisture to escape and help prevent condensation on surfaces like concrete floors and walls, which leads to mold and mildew buildup.


Another common basement air quality issue is dust. Dust is a mixture of dirt, human and animal hair, skin cells, pet dander, lint, fabric fibers, paper particles, and other materials that are small enough to be carried through the air.

The problem with dust is that it can cause allergy symptoms and respiratory problems. In fact, excessive exposure to indoor dust can even cause more serious long-term health problems like asthma.

Musty Smells

If your basement has a musty smell, chances are good that the dampness has begun to foster mold or mildew. Mold is a fungal growth, often green or black in color and ranging from slimy to furry in texture. It can grow on almost any surface and thrives in humid conditions.

5 Tips to Help You Improve Air Quality in Your Basement

There are many ways that you can combat the problems listed above and improve the air quality in your basement. Let’s go over a few of the best ways to do just that. 

1. Improve ventilation

Ventilation is an essential factor in creating good basement air quality. A basement with poor ventilation is more susceptible to mold and mildew, which are both detrimental to the health of your family. 

You can improve ventilation by adding a fan that blows air out of the basement or by using natural ventilation to remove stagnant air from the basement.

2. Use an air purifier

An air purifier can help you clean up the basement’s air and make it healthier. Air purifiers work by continuously fanning the room’s air through a filter to remove pollutants such as mold spores, dust mite allergen, pet dander, and smoke. 

The best air purifiers have HEPA filters that can trap at least 99% of particulate matter 2.5 microns or larger (about 1/100th the width of a human hair). For high-performing air cleaning, look for an AHAM-certified unit with a Clean Air Delivery Rate (CADR) rating higher than its room size.

Air purifiers are particularly helpful if your basement suffers from excess moisture because they can reduce mold spores in the air that may be causing allergies. Also, make sure that you keep your furnace in good shape, as this will prevent moist, conditioned air from entering the basement during the winter months and reducing humidity levels.

Our favorite air purifier for the basement: Coway Airmega 400 Smart Air 

The Coway Airmega 400 is, without a doubt, one of the best air purifiers you can buy for your basement. It features Hyper-Captive air filtration, along with a true-HEPA filtration system, a pre-filter, automatic filter alerts, and even has a smart mode that detects air quality and runs autonomously to ensure optimal air quality in your basement at all times.

3. Control the Moisture

The next step is to control the moisture in your basement. This is because high levels of humidity can cause mold and mildew to grow, in turn causing health problems such as asthma and allergies. You should maintain a consistent temperature, not too hot or too cold, and use a dehumidifier.

Secondly, you should check for any water leakage by looking at the ceiling and walls for stains, peeling paint, flaking plaster, etc. If you see any leaking pipes or cracks in the walls or floor (especially if they are near the ground), get them fixed immediately. 

Also, make sure that your basement floor is insulated and there isn’t any water on it because if there is, it will seep through and increase humidity levels even further.

4. Use a Dehumidifier

You can improve your basement’s air quality by keeping humidity levels at around 50%. Basements are often damp, so the high moisture level can lead to mold and mildew growth. Use a dehumidifier to maintain proper humidity levels. 

Dehumidifiers should be sized based on the square footage of the basement: for example, if your basement is 500 square feet, then you will need a 50-pint (22 L) dehumidifier.

Our favorite dehumidifier for the basement: hOmeLabs 4,500 Sq. Ft. 

The hOmeLabs 4500 is a great dehumidifier for basements because it covers a large area and does an effective job at removing any excess moisture from the air, which in turn prevents musty smells, mold, and mildew from accumulating in your basement. The unit has a sleek design, 50-pint tank, and 24-hour continuous operation mode, with auto-shut-off. You can’t go wrong with this dehumidifier from hOmeLabs.

5. Remove Odors from Furniture and Carpeting

You can use vinegar and baking soda to remove smells from furniture and carpeting. Vinegar is a natural disinfectant, and it also absorbs odors. The acidity of vinegar helps break down the smell-causing particles. 

Simply mix one cup of white distilled vinegar with one cup of water in a spray bottle, then spritz on furniture or carpeting until saturated. Allow the solution to soak for several minutes, then blot thoroughly with a cloth or paper towel to remove moisture. You can also use steam cleaning machines, which are available for rent at many grocery stores or home improvement centers.

Frequently Asked Questions About Basement Air Quality

🤔 Is air quality worse in basements?

So, is air quality worse in basements? Generally speaking, yes. Air quality can be worse in a basement due to the lack of ventilation, which can lead to dampness and mold. That said, there are also plenty of ways that you can improve the air quality in your basement, such as by using an air purifier, a dehumidifier, and improving the ventilation. 

🤔 How do you get the “basement smell” out of a basement?

The combination of ground moisture, water leaks and plumbing issues, humidity, and poor ventilation can mean that basements often suffer from air quality issues. However, there are ways to help improve basement air quality so you can breathe easier and say goodbye to that musty basement smell. The following tips should help: 

  • Get rid of mildew and mold by opening windows and doors during dry weather
  • Use a dehumidifier in places where excess moisture is an issue (like above a sink).
  • Clean up dust regularly with the help of an air purifier. 
  • Maintain good airflow through your home.
  • Use an air purifier with an activated carbon filter to eliminate odors
  • Improve the ventilation in your basement

🤔 How to maintain good air quality in a newly built basement?

When you’re building a new basement, it’s important to make sure that the air quality is safe and healthy in order to protect yourself and your family. Here are the steps you’ll need to take:

  • Control moisture by sealing basement walls, repairing leaks, insulating pipes, and maintaining your gutters and downspouts
  • Fix any cracks in the foundation or interior walls with a rubberized sealant
  • Insulate basement walls and floors with fiberglass insulation
  • Ventilate your basement by using fans or adding vents near doors and windows

Final Thoughts

Basements often suffer from worse air quality than other parts of the home due to the fact that they have less ventilation and a damper, darker environment. However, there are a few things you can do to improve the air quality in your basement, such as operating a dehumidifier or an air purifier, fixing any cracks in your walls or flooring, and improving the ventilation in your basement. 


Asthma and Allergy Foundation of America. (2021). Breathe Easier: Improving Indoor Air Quality in Your Attic or Basement.

Taylor, G. (2022). 7 Health Hazards Lurking in Your Basement. bobvila.comUnited States Environmental Protection Agency. (2022). Introduction to Indoor Air Quality.