5 Reasons Why Your AC Unit Smells Musty

The air coming out of your air conditioning unit is supposed to be odorless. However, sometimes you might notice your air conditioner emitting a musty odor a few seconds after you adjust the thermostat to a cooler setting. To fix this, you will probably need to contact a heating and air conditioning service near me. Here, we give you the top five reasons why this happens and what you can do to solve the problem.

Excess moisture in air ducts or vents

High humidity or an unnoticed drainage leak can cause excess moisture that can accumulate inside air ducts and vents. If a musty smell accompanies the air when you turn on your AC unit, there is a good chance it is because of the mold and mildew that have spread inside the ductwork.

In such a case, you need to call an expert in HVAC installation as soon as possible since mold exposure can cause upper respiratory health issues. The solution to getting out the musty smell, in this case, is to get the ducts and vents cleaned and repaired thoroughly.

Frozen evaporator coils

An AC unit absorbs warm indoor air, removes humidity from it, cools it, and cycles it back indoors through the return vents. What is vital for this process if free-flowing air, which means you must have clean filters!

Dirt and debris can block airflow through the filters, causing water drops from humid indoor air to collect on the evaporator coils. The AC unit’s refrigerant continues to cool the air causing these water droplets on the coils to freeze. This is where the importance of changing air filters at home comes in. It is essential to clean or replace the filters at least once every one or two months.

A full drain pan

The humidity that gets removed from the warm indoor air causes water droplets to fall into the drain pan. This part of the AC unit may not function as effectively over time as it suffers regular wear and tear.

An improperly working drain pan can accumulate mold, which leads to a musty odor when you switch on the AC unit. Call an HVAC ductwork installation expert to get it replaced by a new one.

Blocked condensate line

The condensate line is a small PVC pipe right next to the condenser unit, the part of the air conditioner which is located outside your home. It drains water from the drain pan to your landscaping or storm drain. However, since it is small in size, it's also one of the top locations for mold, mildew, and sludge to accumulate. This can lead to clogs and musty odors when you switch on your AC unit.

Wrong AC unit size

You must have the right size AC unit for it to work properly. If it’s too big for the area, the air gets cycled throughout the area too quickly, which means it doesn’t get dehumidified completely, resulting in excess moisture. Turning the AC unit on and off constantly is also a possible issue with the wrong AC unit size, leading to excessive wear and tear and possible premature failure.

To sum up

These are the five reasons why your AC unit might give out a musty odor. It is important to pay attention when this happens as it can be harmful to your health. You can prevent it from happening by using some of the methods given above. However, if the problem persists, you can contact a heating and air conditioning service near me. They will be able to help you not only with getting rid of musty odors but also with HVAC installation, mini-split AC installation, and HVAC ductwork installation.

At Cardinal, we live and work in our community and always strive to make it better. We know the value of hard work and honesty and strive to give every customer the best experience possible.