Some studies have shown that poor indoor air quality and health issues may be directly related to mold and other irritants lurking inside your heating and cooling system. The good news is that periodic inspection can prevent your air ducts from causing air quality issues in your home.
Contaminants that get inside of duct work will be distributed throughout the building. More than just dust and dirt can accumulate in air ducts. Pollen, pet dander, dead insects and insect and rodent feces are common elements found in air ducts that can cause problems, especially for persons with asthma or allergies. The most harmful toxin commonly found in air ducts as well as air conditioning systems is mold.
Inspecting Air Ducts
A proper inspection of your HVAC system should include the air ducts as well as the mechanical components of your heating and cooling system. For this reason, it is recommended that a professional air duct cleaner performs the necessary checks. However, a home owner can perform a very basic inspection by removing their air vents and registers and using a flashlight to inspect their air ducts. Depending on the size of the home and complexity of the duct work, a home owner may only be able to inspect a portion of their duct work in this fashion. Air vent cleaning contractors have special equipment to inspect the entire duct work system.
What you are looking for is moisture, an overly musty or earthy smell or unusual spots on the surface of the duct work. Mold in air ducts will usual be in the form of little black and white spots or points. Some types of mold can release toxins into the air which can jeopardize the health of residents. If you suspect there is mold in your air ducts it is best to call a professional air duct cleaner for confirmation.
Some dust in air ducts is normal but excessive dust and debris can be harmful. It is not uncommon for insects or rodent to get into the duct work of your home. You may not see the insects or rodents but they may leave feces behind which can be hard to differentiate from normal dust or dirt. Insect and rodent excrement can release harmful toxins and your air conditioner or heater will distribute them throughout your house. If you know you have had rodents or insects in your air ducts or if you suspect they may have been in your duct work it is recommended that you consult a professional air duct cleaner.
When Air Duct Cleaning is Needed
Air duct cleaning is generally not necessary unless a specific condition is present. However, if residents of the home have known health issues such as asthma or allergies they may benefit from regular cleaning since they are more sensitive to airborne dust, pollen, pet dander, etc. In these instances, proactive periodic inspection and cleaning by a professional air duct cleaner, keeping doors and windows closed as much as possible, using high quality air filters, not having pets in the home, not smoking in the home and changing your air filter often can help.
If a homeowner is concerned about dust and debris in their duct work they can clean their registers with a vacuum or wash them with soap and water. They can also use a broom, mop, Swiffer on a pole or similar tool to clean the ducts that they can reach from the register opening. Be sure to clean both the supply and return duct work and registers as well as the near the air filter.
If mold is present and you decide to consult with a professional air duct cleaning company and they concur that mold is present be sure to have them explain how they verified that it is mold. It is best to have to the mold analyzed at a lab.Visual identification is not perfect and a lab can determine how toxic the mold is.
Also ask them to determine what caused the mold so you can prevent it from happening again. If mold is present, an air duct cleaning company may suggest treating the mold using chemical biocides. The EPA says there is some controversy about the health impact of using these biocides in air ducts so proceed with caution. Do your research and consult with your air duct cleaner or get the opinion of other air duct cleaners.