How to Detect and Remove Mold from Your Air Conditioner
Written by: Jason Wall
Mold is a resident's nightmare; it can cause allergy issues, damage your physical well-being, and even ruin your property value. It's particularly alarming when toxic mold grows somewhere out of reach. And in these areas, mold can grow rampantly without detection for a long period of time. One such area is an HVAC system, where mold usually isn't noticed until it appears on vents.
How does mold grow in an air conditioner?
There are a few reasons why mold can grow in an air conditioning system, but the common theme is that excess humidity is the culprit. This might come as a surprise to some, considering that both cooling and heating dehumidify the home. If the air conditioner is used very infrequently − or if the air conditioner is insufficient for the home and produces too much mold-promoting condensation − it could become an inevitable problem for residents for many reasons.
Further problems could be due to water leakages somewhere within or around the HVAC equipment. Any water leakages in a home should be handled as soon as they are discovered, since they're one of the most common and severe causes of mold. And if a home is poorly insulated, cold surfaces within the home can draw condensation and cause widespread mold problems likewise.
How do I detect mold in my AC equipment?
Unfortunately, detecting mold isn't as simple as looking to check. Like fool's gold, there are plenty of substances that can appear like mold, but aren't. Additionally, there are types of mold which are more common and not really dangerous in your system. Finally, several areas of your system will not be visible and might require asking a specialist to show you. Looking to check can provide some confirmation, but the best bet would be to follow your nose. Any musty odors coming from your ducts should raise a red flag immediately. If you observe any moisture in your system, it's nearly guaranteed that you have mold taking residence in it.
If you live in a warm humid area and have the air conditioner on frequently, it's significantly more likely that the source of mold is not within the ducts, but in the equipment itself. This is because running the air naturally keeps the vents dry and cool – not the kind of place that mold wants to call home. And since you're running the equipment, it's likely you're creating more condensation on the air conditioner itself, promoting mold. If you're not cleaning the coils inside of your unit once in a while, I would suggest looking there immediately when you suspect mold issues.
You can also confirm mold by sending a sample to a lab for a small fee, or by purchasing a test kit as available in some stores or online. If your problem is very severe, or if you're having trouble determining the source, the best option would be to cash out for a mold inspection by a professional.
How do I get rid of it?
To ensure that no mold is being blown through the filter, replace or clean it. (If it has a cardboard frame, it likely means you have the replaceable variety.)
Given that the metal of ducts is made of a nonporous material − sheet metal – a mild bleach solution can be extremely effective in cleaning areas that are accessible. Make sure you're only using one part bleach for every ten parts water at a minimum, or your solution might be too harsh and irritate your eyes and nasal passages.
Cleaning your air conditioner is a slightly more complicated process, and only the DIY inclined need apply.
- First, removing the front grille and metal covering, making sure to not force anything and attend to all screws and latching mechanisms. Then, remove the oil plugs from their positions.
- Use a little WD-40 to lubricate the ends of the motor. Drip it very slowly and allow it to spread in an even manner across the surface. Then, brush away and debris and dust from the fins on the front. Do not brush from side-to-side, as this could damage the delicate pieces.
- After allowing it to rest for ten to fifteen minutes, hold the motor carefully with clean rag and run the fins under warm water; be very careful to not touch the coil or any electrical connections.
- Next, remove the plastic covering the rear fins. Cover them in a thin layer of WD-40 and again wait for ten to fifteen minutes.
- After gently wiping off the fan with your cloth, use a vacuum to remove any debris from the machine and surrounding area.
- The final step before reinstalling the machine is to empty the water in the bottom of your AC and allow it to dry for at least four hours.
- Reinstall the system.
Lastly, remember to search for sources of water leakage that might be surrounding your system. Any mold you eliminate today will simply come back tomorrow if you leave a moist environment for it to grow.
Following these steps, anyone can be aware enough to keep their air conditioner free of the hazards of mold growth. Remember to cautiously observe the directions of any chemicals or tools that you use, and consult your air conditioning services provider before engaging in extensive work with your air conditioner if you're unsure of where the mold is, or what steps must be taken to remove it.
Jason Wall is an HVAC technician of more than 23 years who writes advice for professionals and novices alike. He loves spending time with his family, watching baseball, and connecting with others in the HVAC industry. He writes for Griffith Energy Services.
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