Your air ducts are a vital part of your home’s infrastructure, circulating warm or cool air throughout your property.

But like any system, your air ducts WILL get dirty over time. Dust, mold, bacteria and other contaminants can collect in your system, and will be pushed out all around your home if not properly removed.

Here are 4 signs that your air ducts need to be cleaned:

Visible Mold / Organic Growth

This first point may seem obvious, but it’s still critical. Visible mold growth inside hard surface (e.g., sheet metal) ducts or on other components of your heating and cooling apparatus is a major sign that your system needs to be cleaned. While dirt, dust, and other contaminants can harm your health, mold is a completely separate and more serious issue. If moisture is causing the mold growth, you may need to address how that moisture is entering the system.

Rodent / Vermin Infestation

Mice, insects and other pests often use your duct system as a highway to travel all over your property. In addition to being unsanitary, rodent and vermin droppings can lead to unpleasant odors in your system. If you discover rodent droppings or any other indication that rodents or insects could be living in your ducts, it’s time to clean them out.

Weak / Inconsistent Air Flow

If you begin to notice that air is not flowing consistently from room to room, you may need to get your ducts cleaned. This could be an indication of a blockage. Dirt, dust and other contaminants build up over time and can restrict the flow of air at different locations in the system. If you see dirt and debris around your air vents, there is a good chance that your ducts have some blockage. This can escalate allergy problems and other respiratory illnesses.

Strange Noises

Every home has its own unique creaks and squeaks. However, unusual noises coming from your duct system could indicate a problem. If you hear anything more than the motor to your blower, or a vague “swooshing” noise, your ductwork could be blocked or have debris. If you encounter unusual noises, it’s time to have professionals take a look.