You should consider air duct cleaning if there is substantial visible mold growth inside hard surface (e.g., sheet metal) ducts or on other components of your heating and cooling system. Also if your ducts are infested with vermin, e.g. (rodents or insects); or; if your ducts are clogged with excessive amounts of dust and debris and/or particles are actually being released into the home from your supply registers.

The most effective way to clean air ducts and ventilation systems is to employ Source Removal methods of cleaning. This requires a contractor to place the system under negative pressure, through the use of a specialized, powerful vacuum. While the vacuum draws air through the system, devices are inserted into the ducts to dislodge any debris that might be stuck to interior surfaces. The debris can then travel down the ducts to the vacuum, which removes it from the system and the home.

Heating, ventilation, and air conditioning (HVAC) systems have been shown to act as a collection source for a variety of contaminants that have the potential to affect health, such as mold, fungi, bacteria, and very small particles of dust. The removal of such contaminants from the HVAC system and home should be considered as one component in an overall plan to improve indoor air quality.

Research by the U.S. EPA has demonstrated that HVAC system cleaning may allow systems to run more efficiently by removing debris from sensitive mechanical components. Clean, efficient systems are less likely to break down, have a longer life span, and generally operate more effectively than dirty systems.

The most effective way to clean air ducts and ventilation systems is to employ Source Removal methods of cleaning. This requires a contractor to place the system under negative pressure, through the use of a specialized, powerful vacuum. While the vacuum draws air through the system, devices are inserted into the ducts to dislodge any debris that might be stuck to interior surfaces. The debris can then travel down the ducts to the vacuum, which removes it from the system and the home.

Frequency of cleaning depends on several factors, not the least of which is the preference of the home owner. Some of the things that may lead a home owner to consider more frequent cleaning include:

• Smokers in the household.
• Pets that shed high amounts of hair and dander.
• Water contamination or damage to the home or HVAC system.
• Residents with allergies or asthma who might benefit from a reduction in the amount of indoor air pollutants in the home’s HVAC system.
• After home renovations or remodeling.
• Prior to occupancy of a new home.

NADCA and the EPA recommends every 5 to 7 years. If you have pets, allergies or a source that produces an unusually large amount of dust you may need it done more often.