Wednesday, June 19, 2024

Why Do My Ac Vents Have Mold

Black Dust On The Air Vents

Cheap and Easy Way to Kill Allergy Causing Mold from Air Conditioning System

If you see black dust on the surface of an air vent that cant be easily cleanedit is likely a species of mold or mildew, and an early sign of black mold in the air vents. If mold is inside your air duct system, the spores can get blown to the vents, and eventually end up as a black dust.

Also, mold can start growing on the air vents themselves because dust accumulates on the surface which is a food source. Cleaning the visible mold on vents is recommended because the mold may release spores into the air, possibly causing harmful health issues.

Read Also: How Much Are Home Inspections For Mold?

Is Black Mold On Air Conditioning Vents Dangerous


Remember when we were kids and couldnt wait to grow up? Today, you probably realize that things are a bit more complicated than what you imagined in grade school. As an adult, you likely enjoy many aspects of your life, but you also recognize that theres a lot more involved than just being able to set your own bedtime!

As a homeowner , there are more things to manage than you might have realized when you signed on the dotted line, including overseeing whether your HVAC unit is running optimally. When things go wrong, it can have an impact on your familys level of comfort, health, and finances.

For this reason, its best to establish a routine maintenance plan so that any potential problems can be identified and addressed as soon as possible. One unpleasant issue that regular maintenance might reveal is the appearance of black mold in your ventilation system. This is one problem you definitely dont want to ignore!

What is Black Mold?


Youve probably heard the term black mold, but many probably dont fully understand what it is. Black mold, or Stachybotrys chartarum, is a greenish-black mold that grows on materials such as fiberboard, gypsum board, paper, lint, and dust when there is moisture from water damage, excessive humidity, water leaks, condensation, water infiltration, or flooding.

How to Spot Black Mold

Aaron Amat/

Health Impact of Black Mold

  • Difficulty breathing
  • Nausea
  • Vomiting and/or diarrhea

How To Prevent Musty Mildew Smells From Car Ac

Your first task of action should be to locate the drain tube in your vehicle and ensure that it is functioning properly. You might want to bring your vehicle into a trusted dealership or repair shop to prevent causing further damages to your vehicle.

If the drain tube appears to be in proper working condition, you can rule this problem out and look at killing off the mold currently within your cars AC system in addition to preventing new mold from forming in the future.

Here are some ways you can do so

  • Turn off the AC 2-5 minutes before you shut off your vehicle but leave the fan on. This will allow the entire AC unit to dry much more thoroughly every time you use it.
  • Clean or replace your AC filters. Dirty air filters reduce airflow through your AC and help moisture remain inside the unit. Be sure to replace the AC filters as often as recommended by the manufacturer of your vehicle.
  • Spray an antiseptic into the exterior air vents . Be sure your AC is set to the setting that pulls air from outside in, so that the spray is pulled into the ventilation system and can directly work at killing of mold and bacteria.
  • Car ac smells bad? Try changing your air filter as it can collect debris that can introduce mold or act as an additional food source for mold.

    Read Also: How To Clean Mold On Refrigerator Seal

    Dealing With The Black Dust Surrounding Your Air Vents

    Have you ever wondered what the black dust is on the ducts and ceiling or the black stuff pouring out of your air conditioner vents is? And not only that, but are you wondering if it is hygienic and safe to allow it to stay there? It is black mold, and it is definitely not good for your health to allow it to stay there. So it would be best if you got rid of it as soon as possible.

    Black dust coming from your air vents may cause many different health problems, including difficulties with breathing, throat irritation, continuous sneezing, and eye irritation. Black dust surrounding air vents is a bad sign. Although this dust might look inconsequential is is a severe threat to your well-being and good health. So today, we will be discussing how to get rid of the black dust surrounding your air vents.

    How Does It Happen

    Black Mold On Ceiling Vents

    Mold is common in dark, damp, dirty places, which provide the perfect environment for it to thrive. Unfortunately, AC systems meet this description perfectly. Mold spores naturally traveling in the air attach to damp areas and grow there. AC technicians often find mold on the exterior of air conditioning systems and ducts rather than the interior. Some problem areas for mold are:

    • Supply plenum
    • Trunk line

    Also Check: How To Remove Black Mold From Shower Tile

    Signs Of Mold In Air Vents

    In most cases, youll feel mold in your vents before you actually see it. Breathing in the contaminated air can result in a range of physical symptoms, which can vary from person to person. The most common red flags include:

    • Itchy and irritated eyes
    • Impaired concentration

    In addition to these health concerns, you might also smell the mold itself.

    Is there a persistent, musty odor present in your home that you only notice when the A/C is running? If so, it could point to the presence of mold nearby.

    There are many behind-the-scenes issues that could lead to mold in your air vents. Sometimes, it develops in the aftermath of a flood. Other times, it can signal an operational problem with your HVAC system. Either way, its important to address it as soon as possible to avoid further complications.

    Why Does Mold Grow On Air Vents

    Mold favors environments with high humidity. When air passes through your air ducts, especially if the air outside is humid, water droplets can form and the moisture can become the perfect spot for mold to grow. Additionally, mold can grow quickly in your air ducts and vents because it can feed on the dirt, dust, dead skin cells, pollen and dander that builds up in your ducts.

    Also Check: How To Handle Mold In Your House

    Problem #: An Oversized Ac

    But I thought bigger was better?

    Well, not when it comes to air conditioners. If your AC is too big for your home, it will short-cycle. Short cycling occurs when an oversized air conditioner blasts your home with cold air, then shuts down quickly.

    If your air conditioner is oversized, it means your AC wont run long enough to remove moisture from your homes air. When that moisture meets dust mold/mildew can form.

    Symptoms Of Mold In Air Ducts

    What should I do about mold in my AC system?

    Black mold can cause negative health effects if its in your home. It can affect the respiratory system and cause uncomfortable irritation. If you have a black mold infestation in your air vents, you and other residents will likely experience some physical symptoms. Some physical signs to watch for in you and your family include:

    Act Now and Remove Mold from your HomeCall a Professional Mold Remediation Specialist or Get Up to 4 Quotes Now.

    • Irritated feelings in eyes, nose, and/or throat. Symptoms may get worse when AC is turned on.
    • Persistent headache whenever you are home, but goes away when you go outside. If anyone in your household is experiencing this symptom, you could have black mold in your HVAC.
    • Allergy symptoms like runny nose, itchy eyes, or rashes.
    • Nausea, fatigue, or dizziness whenever you are inside the home.

    If you, your family, or anyone that frequents your home is experiencing these symptoms you could have mold in your HVAC system. Please contact a professional to check the vents.

    Also read our in-depth article on: Black mold symptoms.

    Read Also: How Does Mold Make You Sick Symptoms

    What Are Sings Of Mold In Air Conditioners

    There are a few signs to watch for if you suspect mold in your air conditioner:

    • Musty smell. Mold spores give off a distinct musty smell. If you have a central AC unit, you might notice a musty smell throughout the house with no discernable source or visible signs of mold. If you have one or more window air conditioners, you might notice this smell in the room where the unit is located. A musty smell coming from an air vent when the AC is running is a clear sign of mold in your air conditioner.
    • Health symptoms when AC goes on. Mold can cause a variety of negative reactions, including allergic reactions and various respiratory problems. If you or someone in your family starts showing these symptoms only when the AC is running, mold may be the culprit.
    • Visible signs. Of course, depending on the location of your AC unit, you may be able to give it a visual inspection, along with the air vents if you have central air conditioning. Look for the familiar patchy spots of mold, sometimes fuzzy and often black or green-black. But keep in mind that mold spores are microscopic and the source of them may be hidden from view. So even if you cant see any mold, it may still be lurking out of sight.
    • Professional inspection. If you suspect mold in your air conditioner, the best way to be certain is to bring in a professional mold inspector. They will be able to determine if there is mold in your AC unit, in the ventilation system, and other parts of your home.

    Signs Of Mold In Home: Is This Mold In My Hvac Vents


    Most home air conditioning and heating systems have or will become discolored with visible mold or visible dust to some degree – but it’s not normal or healthy for your ducts to become excessively moldy or to produce a strong mold odor.


    It’s important to look for signs of mold in home because mold spores from your air conditioning and heating ducts can potentially result in health problems, and even mold odors in the absence of mold spores have been shown to cause health problems. In fact, according to a 2005 study conducted by the National Institutes of Health and cited in Total Health Magazine, one out of every six allergy sufferers’ symptoms can be directly linked to the mold and bacteria found in their air duct systems. Most people are exposed to some mold every day without suffering any side effects, but people with mold allergies can have a reaction if exposed to too much mold, including symptoms such as wheezing, rashes or hives, itchy eyes, and respiratory failure.

    Also Check: How To Eliminate Mold Smell

    What To Do About Black Dust Around Air Vents

    Whats an even better solution to stopping black mold? Keeping it from ever growing in your air ducts or anywhere in your house in the first place.

    You can save yourself money, stress, and health issues by taking steps to prevent mold infestations before they occur. There are a few tactics you can use to stopping black mold from growing in your air ducts and home.

    Why Does My Air Conditioner Have A Burning Smell

    Black mold vent first view

    Burning/Electrical Odors Electrical odors could indicate a mechanical problem with your AC fan or compressor, wiring issues, or electrical component failure. Made with a variety of metals and chemicals, prolonged exposure to these fumes is not healthy.

    Every time your AC comes on, the air leaving your vents stinks with a musty odor. What in the world could it be? Every time your AC comes on, the air leaving your vents stinks with a musty odor. What in the world could it be? Most likely its the smell of mold and/or mildew.

    Solution: Clear the condensate drain line. You can try a DIY drain clean. Or hire a professional to clean it for you. If your cooling system was a body, the air ducts would be the respiratory system. They carry air to your living spaces.

    Also Check: What Can Get Rid Of Black Mold

    Incorrect Ac Size For Home

    For your AC system to work correctly, it needs to be the correct size for your home. If its too large, the air gets cycled too quickly, leading to a lack of dehumidification and an increase in excess moisture. If its too small, it will turn on and off constantly, leading to premature failure.

    Ask your HVAC technician to check if your air conditioning unit is the correct size. HVAC unit sizing is about more than your homes square footage. Your service technician will also consider the number of people who live there, your homes insulation type, and your needs based on your local climate.

    Where To Look: Ask your service technician to evaluate your system.

    Do Sealants Prevent The Release Of Dust And Dirt Particles Into The Air

    Manufacturers of products marketed to coat and encapsulate duct surfaces claim that these sealants prevent dust and dirt particles inside air ducts from being released into the air. As with biocides, a sealant is often applied by spraying it into the operating duct system. Laboratory tests indicate that materials introduced in this manner tend not to completely coat the duct surface. Application of sealants may also affect the acoustical and fire retarding characteristics of fiber glass lined or constructed ducts and may invalidate the manufacturer’s warranty.

    Questions about the safety, effectiveness and overall desirability of sealants remain. For example, little is known about the potential toxicity of these products under typical use conditions or in the event they catch fire.

    In addition, sealants have yet to be evaluated for their resistance to deterioration over time which could add particles to the duct air.

    Recommended Reading: How Can You Kill Black Mold

    Should Chemical Biocides Be Applied To The Inside Of Air Ducts

    No products are currently registered by EPA as biocides for use on fiberglass duct board or fiberglass lined ducts so it is important to determine if sections of your system contain these materials before permitting the application of any biocide.

    Air duct cleaning service providers may tell you that they need to apply a chemical biocide to the inside of your ducts to kill bacteria and fungi , and prevent future biological growth. Some duct cleaning service providers may propose to introduce ozone to kill biological contaminants. Ozone is a highly reactive gas that is regulated in the outside air as a lung irritant. However, there remains considerable controversy over the necessity and wisdom of introducing chemical biocides or ozone into the duct work.

    Among the possible problems with biocide and ozone application in air ducts:

    • Little research has been conducted to demonstrate the effectiveness of most biocides and ozone when used inside ducts. Simply spraying or otherwise introducing these materials into the operating duct system may cause much of the material to be transported through the system and released into other areas of your home.
    • Some people may react negatively to the biocide or ozone, causing adverse health reactions.

    How Do I Know If I Have Mold In Vents


    You may be able to physically see mold spores growing inside your HVAC air ducts. Take the vent cover off and visually inspect the inside of your vent with a flashlight. Look for dark black dots.

    The other telltale sign of mold is a musty, damp smell that may become stronger when your air conditioner or furnace is turned on.

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    Next Steps Of How To Get Rid Of Mold In Air Ducts:

  • Start by turning off the heating/cooling vents.
  • When you can reach the spot, start scrubbing the moldy areas thoroughly with a wet rag or a light brush.
  • Repeat the process for a visibly extensive mold infestation.
  • Dispose of the rags in airtight trash bags. Use six mil or thicker trash bags for discarding them.
  • Once you have finished cleaning the visible mold, it is time to make sure that it never comes back! You need to look for EPA registered mold growth inhibitors for this process. These can successfully prevent mold from growing again after the clean-up. Without the application of inhibitors, the fungus is most likely to come back in the same area within a few weeks.

    It sounds like a time-consuming task when it comes to the process of how to get rid of mold in air ducts and it surely is. You should be especially careful to dry the area after the cleaning. It is also a process that involves high health risks. Experts will always recommend that you leave the task of how to get rid of mold in air ducts to professionals who have the right equipment to ensure maximum safety to you and your family during the process.

    How To Remove Mold From Air Conditioner

    We dont recommend that homeowners attempt to clean a central air unit or ventilation . If, on an inspection of a small self-contained unit, you have decided to tackle it yourself, heres what youll need to do:

  • Wear goggles, a face mask and gloves to avoid exposure
  • Move the unit to a space where you can clean it without cross-contaminating your house
  • Open the unit and remove the filter
  • If the filter is disposable, throw it out
  • If the filter is not disposable:
  • remove all debris and visible mold
  • fully submerge the filter in a mix of 1 part bleach to 10 parts water
  • let soak for at least 10 minutes
  • rinse
  • air dry
  • Use a wet/dry vac to remove all debris from the interior of the unit
  • Deep clean all affected surfaces using a mixture of 1 parts bleach to 10 parts water, adding a spoonful of detergent for extra penetration.
  • Allow at least 10 minutes for the bleach to kill off any last remnants of mold
  • Hose or otherwise rinse off the unit, but avoid soaking the electrical components
  • Allow to dry
  • Reinstall the filter, reassemble and reinstall
  • If youre intimidated by the above work, remember: hiring a mold removal expert is always a safe and sure-fire way of getting mold eradicated.

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