Reasons Your Air Conditioning Smells Musty

It can be quite frustrating to switch on your AC after a long day of work only to find that your room is now filled with a bad smell. There is nothing to worry about if your AC is throwing cool air bind with a bad stench that you can’t stand as this problem is very common at the start of the season and there are a couple of reasons for this cause.

The smell can be different and depends on the condition you left your AC in the fall last year. Sometimes it can smell like something is burning or it can be even a smoky or musty smell. All of this depends on the weather and room conditions and having the AC switched off for a long time without proper maintenance is the root cause of this smell.

We will look at the main reasons that cause this smell and how you can get rid of it.

Why Does My AC Unit Smell Musty?

The HVAC system comprises several different components. Therefore, the root cause might not be only your indoor unit or the drain system, it can be one or more components especially if you have a duct system installed. The musty smell is generally due to the growth of mold that is the result of the accumulation of moisture.

If your air conditioning system has been shut off for a long time with the moisture trapped inside, the mold growth is obvious and when you turn the AC on, the air is mixed up with the smell of mold that spreads in your entire room. Hence, it is crucial to inspect each and every area of your AC system to find out the areas of mold growth and moisture accumulation.

The first and foremost common area is your Drain Pan. The indoor unit absorbs the humidity inside your room and thus the excess water is collected in the drain pan before it is drained through the pipe. If the collected water remains in the drain pan for several months, mildew starts to grow which causes a musty and stale smell.

Another area to check is your Evaporator Coil where the mold grows due to the collection of dirt and moisture. The evaporator coils are embedded through the aluminum fins and hence, a lot of area for mold growth. As the indoor unit also uses an air filter, all the dirt, dust, and moisture also get collected there in large quantities resulting in a foul smell. Similarly, the duct system can also suffer mold growth if there is water leakage in the ducts and vents.

How Do I Get My AC to Stop Smelling Musty?

We believe that precaution is always better than cure. Thus, if you don’t want your AC to smell bad again, there are a couple of things you can do that will not cause a musty smell even if you keep your AC switched off for a very long time.

The best way to stop the growth of mold is to get your AC indoor unit cleaned properly. Make sure you get the evaporator coil and drain pan washed with water. This should be done at the end of the season and in the spring season next year as well.

Clean Air Conditioning Unit Filters Often

Similarly, it is also important to clean the air filter that doesn’t need a professional as you can simply take it out and wash it properly before putting it back. However, for cleaning the whole AC outdoor and indoor units, you should always hire professionals as there is a risk of getting an electric shock if you don’t know the proper sequence for cleaning.

How do you clean a moldy air conditioner?

The process of deep cleaning your AC is time-consuming and air conditioning professionals know exactly where the mold can grow and therefore, are experienced in troubleshooting and eliminating the mold totally from the root. Make sure you get all the important steps executed in cleaning your AC.

For the indoor unit, it is fine to clean the air filter but better if you get it changed if it has become dull and clogged to the point where it can’t be unclogged. These filters are needed to be removed before accessing the evaporative coil. To clean the coil, all you need is a good pressure water spray and some detergent to remove any debris or mold.

The next step is to clean the drain line. Certainly, it is the most prone area for mold growth as it is responsible for getting the condensate water to the drain. Make sure you flush the drain line regularly so that nothing stays in the line for a long time.

Lastly, you should dry the indoor unit as much as possible. You can do this with the help of pressurized air and by wiping the insides of the indoor unit with a dry soft cotton cloth. If you use a wet wipe then, do avoid its contact with electrical connections or parts. After cleaning the unit, leave its door open for a few hours to let it dry completely. This will stop the growth of mold quickly for the whole season.

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