How to Make Air Ducts Smell Better and Eliminate Odors

One of the major functions of air ducts is to deliver fresh air and remove stale air. Common causes of foul smells in the air ducts include dead animals, mold and mildew growth, urine, and clogged filters. Mold and mildew growth, for example, could cause allergic reaction symptoms. It's vital to know how to make air ducts smell better.

The following steps help make the air ducts smell better:

  • Using baking soda
  • Cleaning or replacing the air filters
  • Eliminating contaminants from the air ducts
  • Maintaining a clean evaporator coil
  • Draining the condensate line
  • Cleaning the HVAC regularly
  • Hiring a professional air duct company

Let's discuss each of the above, so read the entire article.

man holding his nose, looking down, as he wonders how to make air ducts smell better

Types of Air Duct Odors

Various smells signify an underlying problem in your air ducts. Some could be minor, but others are severe and require experts to address quickly.

Rotting Carcass Smell in Air Ducts

If there's a hole in the air ducts, pests will easily access it. Once the pests are trapped there, they may die and rot, resulting in a rotting carcass smell in your home.

Wear your gloves and turn off the HVAC system. Remove indoor vent covers to remove dead pests from the system. Put the carcasses in a plastic bag, especially if they're rodents because they can infect you with diseases.

If the carcass is in a hard-to-reach area, use a wire hanger to pull it out. Disinfect the area to avoid contamination.

If it seems impossible to remove the carcass, especially if it's in the final rotting stage, contact a professional to clean the ducts and fix any openings to prevent pests from reassessing it.

Air Duct Electrical Smell

A clogged or dirty air filter emits an electrical smell. Please turn off the system and inspect it. Clean the system if it is dirty or contact the professionals to clean it.

Oily Smell from Vents

If the HVAC oil burner system is faulty or there's oil leakage, you'll sense an oil smell in the air ducts. Call a professional to address the issue; it's complex.

Bad Egg Smell

A bad egg smell may signify a natural gas leak, which ONLY a professional should address.

As you wait for the professionals to arrive, open the windows and the doors, vacate the house, and then walk away to a safe distance.

Moldy Smell in Air Ducts

Mildew or mold growth in the HVAC system emits a moldy smell. You can use oil cleaner to clean the electrical coil if it's infected by mold.

Mold growth in the air ducts causes allergy symptoms. So, clean the HVAC system or contact a duct cleaning professional company, mainly if it has spread to other areas of your home.

Hot Gas Smell from Air Vents

When the accumulated dust in the HVAC system heats up, it smells like hot gas. It's normal but should not last for an extended time. If it does, contact a professional for an HVAC inspection.

Urine Smell in Air Ducts

Whether from pets, rodents, other animals, or human children or adults, the ammonia-like smell of urine in your vents and registers can be overpowering and affect everyone's health. There are some ways to get urine smell out of air ducts yourself, but a professional air duct cleaning service is always your best and safest bet.

before and after of inside a dirty and clean air duct vent which previously smelled
Before and after Zerorez cleaned this air duct vent

How to Make Air Ducts Smell Better

A musty smell in the air ducts signifies mold and mildew growth. A deep cleaning is necessary. Deep clean the air ducts if you know how to clean them safely and correctly.

Have the cleaning solutions, approved air duct odor eliminator, and everything else needed for the task beforehand. Turn off the system before beginning the work.

Wear the following protective clothing to safeguard your health:

  • Gloves
  • Long pants
  • High-quality face mask
  • Long-sleeved shirt
  • Work boots or closed toes shoes

NOTE: If you don't know how to clean air ducts or you haven't cleaned them before, please hire a professional.

Here are workable tips on how to remove musty smell from air ducts: DIY!

Solution #1: Use Baking Soda

You can temporarily fix a musty smell by using baking soda. Strategically place baking soda in the duct to absorb the musty smell.

Solution #2: Clean the Evaporator Coil

The evaporator coil is responsible for cooling your home but is easily infected by mold and mildew. Use a homemade cleaning solution or buy one from the stores. Never use non-diluted bleach on the coil. Add 10% bleach in clean water and use it to clean the coil.

To correctly and safely clean the evaporator coil, follow the following steps.

  • Disconnect the access panel: Remove the access panel to access the evaporator coil. Follow the user manual for instructions on how to remove it.
  • Vacuum the coil: Brush away the contaminants on the coil (indoor) and other condenser parts using the hose attachment.
  • Repair damaged fins: Using an HVAC fin comb or a screwdriver, repair any misshapen or damaged fins. Loosen the hex screws, and remove the fins.
  • Clean the coils (outdoor): Spray the cleaning solution on the coils and then wipe dry with a clean cloth. Remove the collection pan; spray the cleaning solution on it and then dry it.
  • Reassemble: Reassemble the parts and then turn on the system to test if the musty smell has disappeared.

Solution #3: Clean the AC Condensate

Drain Line Excessive moisture drains out of your air conditioning system through the AC condensate drain line. Once it is clogged, the water ceases to drain. It flows back to the collection pan, creating a conducive mold and mildew growth environment.

Once the water starts pooling in, it causes a musty smell in the air ducts. Use a wet vac with a high suction power to suck out excess water and clogs in the drain pipe.

If there are no clogs or water, contact a professional to inspect the condensate drain or the entire system.

Solution #4: Clean or Change the Air Filter

Air filters keep the air in your home fresh. After some time, dust and other particles build up, blocking the flow of air, which sometimes results in mold and mildew growth.

To clean the air filters:

  • Disconnect the air filters from the HVAC and then use the vacuum to clean all the contaminants. Remove excess dust using a clean, dry dusting cloth.
  • If you can't see anything shining through after cleaning, buy new filters and replace them.
  • Test the system by running it to see if it's functioning correctly and if the musty smell is gone.
  • If the smell persists, contact a professional for help.

Changing your air filters at this point is advisable if you last changed them a long time ago. You can replace your air filters every three months or as the manufacturer recommends.

You can also install air purifiers or air filtration systems to capture airborne particles and neutralize odors. Choose units with activated carbon filters, which are effective at absorbing odors.

male Zerorez air duct cleaning technician lifting off a floor air vent cover in order to clean it and remove the smells

Solution #5: Clean the Vent Covers

Unscrew the vent covers and, based on their material and brand, clean them accordingly. For most brands and materials, you can use warm, soapy water and a cleaning brush to remove persistent residue.

Rinse the vents and leave them in a cool place to air dry, or use a dry towel to dry them completely. Screw the dry vents back and test the system.

Solution #6: Buy Duct Filter Pads

Before you contact a specialist, after everything else has failed, consider buying duct filter pads. Buy duct filter pads that match the shape and size of the duct vents. They

To install them, unscrew the vent covers and place the filter pads underneath, and then screw the vents again.

Run the system to determine if the odor is gone. If not, an expert should offer a workable solution. Contact one.

male Zerorez technician deep cleaning the HVAC system in the ceiling of a home to help remove musty smells from air ducts

Solution #7: Hire the Experts

If the musty smell doesn't cease despite trying the above DIY methods, it's time to contact a professional. Professionals know how to remove odor from air ducts and can help with it.

There could also be other underlying issues that may need trained and qualified air duct experts. Below are signs that you need to contact a professional.

  • Recurring mold and mildew growth
  • Invisible clogs in the ductwork
  • Pest infestation in the air ducts
  • Leaks in the air ducts

You can clean the air ducts yourself. If the problem persists, the pests keep returning and getting trapped, or if there's a bad egg smell, engage an air duct cleaning professional immediately.

The Zerorez® Team is trained and will clean up your air ducts, leaving them smelling better. Call us at 866-937-6739 or schedule a service online from the comfort of your home.

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