On a scorching summer day, you expect to be able to relax and be cool inside your house. But when there’s a terrible smell from your AC, it ruins your day. You don’t know what it is or if there’s anything you can do about it. How do you fix a musty smelling AC?

Generally, a musty, moldy smell indicates bacterial or mold growth somewhere in the HVAC system. This can grow in the drain, evaporator coils, drain line or drip pan of the air conditioning system. It will stink up the whole house. Some of the most likely things to check are=:

• Check if the AC drain pan is full.
• Check for frozen evaporator coils.
• See if there’s moisture in the air ducts or vents.
• Check for a clog in a condensate line, or a dirty line.
• Call an expert to see if the HVAC system is the right size for your house.

Why Are Foul Scents a Concern?

Whether the bad smell is the smell of filthy socks, rotten eggs, must or mold coming from your vents, all scents indicate an underlying problem with your air conditioning system.

In some cases your cooling and heating unit may give off a burning odor at the beginning of a cooling or heating period as dust that has actually built up in the system somewhere burns off. If you smell rotten eggs it could indicate there is a gas leakage or a dead animal in your vents.

A filthy sock smell, or stuffy odor, implies you might have a mold growth. A mildewy smell normally suggests there could be pollutants existing in your air conditioning system. Since your system is a dark and damp area most of the time, it’s a breeding ground for bacterial growth. This indicates your air conditioning is spreading out hazardous mold and mildew spores into the inside of your home. These spores can trigger severe health issues, particularly if one of your family members fights with allergic reactions.

You shouldn’t neglect or ignore strange scents coming from a home HVAC system, be it heating or cooling. The best way to get to the bottom of your odor problems is to call an expert HVAC professional to inspect and service your system.

Reasons an AC Smells Musty

If you’re trying to figure out the issue yourself, or waiting for an HVAC technician to come to your house, you may be able to see what’s going on. You may be able to DIY the problem or help the technician. This could help the work go quicker and better. Here are five typical reasons why your AC has a musty odor.

Full Drain Pan

An air conditioning system removes humid air from an interior. This causes condensation, which then collects in a drain pan. There’s some normal wear with this part of a system. It shouldn’t be full or overflowing however. There shouldn’t be corrosion or standing water, where stuff can stay and grow, such as mold and bacteria. A technician can put in a new drain pan.

Frozen Coils

As an HVAC system brings in warm air, it gets rid of the moisture in the air to cool it, then puts the cooler air out into the home through ducts and vents. Evaporator coils can freeze at times. This hurts the airflow and makes it more likely dirt, allergens and debris are in the airflow. An HVAC pro can thaw the evaporator coils, change filters, clean the parts in the system and make it as efficient as it should be.

Blocked Condensate Line

An HVAC system’s condensate line is a small pipe next to a condenser unit, the big machine outside the house. The condenser line drains water from the drain pan as the system creates, then has to remove, the evaporated moisture.

A backed up condensate line can cause a problem in a drain pan, and all the way back along the line to other components, including the air quality inside. Musty, moldy, contaminated smells can start here and cause problems everywhere.

Moisture in Ducts and Vents

The humidity removed from the warm air as it’s cooled can also gather and stay in the ductwork or vents of your system. This is more likely in hot and humid areas and hot and humid times of the year. The system is having to work extra hard in, for example, a Carolina summer. If you have a system that’s a little inefficient, older, or a little behind on maintenance, these are added factors, too. Excess or standing moisture creates a mess and stuff can grow inside the ducts, which all the air in your home passes through. This might need a technician to check it, then do a pro caliber duct cleaning.

The Wrong Size HVAC

For your AC and HVAC to work efficiently, these systems need to be the efficient, right size for the area which needs to be covered. If the system is too large you might not think this is a problem but it can be. In this case, the air is cycled too fast which means it is leaving too much humidity in it.

If the HVAC system is too small to handle the space, you can get poor or inefficient cycling of the system on and off. This increases energy usage. It can cause added strain, then failure, of parts or the whole unit.

You’ll need to ask an HVAC technician about the size and coverage of your home’s system. A proper evaluation looks at more than simply a home’s square footage. Other factors include climate, region, insulation, number of people in the home and other specific differences.

At South End Heating and Air we specialize in HVAC and furnace repair, call us for a free consult and free estimate. We’ll evaluate your system and help make recommendations for optimum value. After all, we want to keep you cool all summer long and warm in the winter. Just schedule a visit with one of our technicians to talk about how we can help with your heating needs. Would you like to learn more options our techs can help you with? Give us a call 704-684-5339.