Why Does My Air Conditioner Smell Bad?

Does your air conditioner smell bad? Does it downright stink? For Raleigh residents, air conditioning is non-negotiable in the sticky summertime. But if a less-than-pleasant aroma wafts from your unit, you may have a problem.

What are some of the possible causes for a bad smell emanating from an air-conditioning system?

The System Is the Wrong Size

Air conditioners need to be sized appropriately for the space they’re cooling; having a unit that’s too big or too small can cause issues. If your unit is too big for your space, it may not be able to properly dehumidify the air. Mold spores can grow, resulting in a musty smell. If you’re detecting an unpleasant smell, a too-big system could be the culprit.

The Cooling Coils Are Grimy

Your cooling system works by sending air across cooling coils. If the coils are dirty — or if bacteria and other nasties are hanging around on them — a bad smell can result.

The Water Drain Is Clogged

A clogged water drain also can cause your system to smell bad. If the drain becomes blocked by particles of dirt and grime, the water may collect in the drain pan, causing an unpleasant odor. In warm climates — like Raleigh in the summer — bacteria, mold and mildew can grow inside the evaporator coil, adding to the musty odor that can spread throughout your house via the ductwork.

The Filtration System Is Ineffective

Your air filtration system is designed to remove a variety of contaminants from the air in your home. If the filtering system has an issue that’s reducing its effectiveness, a bad odor in your home can result.

The Unit Is Being Used Incorrectly

Certain ways of using your system can contribute to a foul smell in your home. For instance, running the system on low speed all the time can cause inadequate dehumidification, which can lead to the buildup of moisture and the growth of mold and accompanying bad odors.

Keep Your System Smelling Great

Few systems in your home are as important as your air conditioner in the summer, and you don’t have to endure foul odors in exchange for keeping cool. If you’re starting to detect any “off” smells, consider having your system cleaned and fully checked. In the Raleigh area, contact Delta Heating & Cooling at (919) 256-5120 to schedule your service appointment.