Heating, ventilation and air conditioning (HVAC) systems can be a collection site for contaminants that could aggravate your allergies. The removal of these contaminants from the HVAC system and home can improve your indoor air quality. Duct cleaning refers to the cleaning of various heating and cooling system components of these forced air systems, including the supply and return air ducts and registers, grills and diffusers, heat exchangers, heating and cooling coils, drip pans, fan motor and fan housing and the air handling unit housing.
According to the Environmental Protection Agency (EPA), the benefits and possible problems of air duct cleaning is limited. However no evidence suggests that this cleaning would be detrimental, provided it is done properly.
You should consider having your ducts cleaned if:
The most effective way to clean HVAC systems is a source removal method. A service provider will use specialized tools to dislodge dirt and other debris in ducts, then vacuum them out with a high powered vacuum cleaner. The service provider may also propose applying chemical biocides, designed to kill microbiological contaminants, to the inside of the duct work and to other system components. They may also suggest applying chemical treatments to encapsulate or cover the inside surfaces of the air ducts and equipment housings because they believe the treatment will control mold growth or prevent the release of dirt particles or fibers from ducts. However these practices have not been fully researched and should not be done routinely.
Duct cleaning services range in cost from $450 - $1000 per HVAC system, depending on the services offered, the size of the system to be cleaned, system accessibility, climactic region, level of contamination and type of duct material.
Air duct cleaning companies must meet stringent requirements to become a National Air Duct Cleaners Association (NADCA) member. Members must have certified Air System Cleaning Specialists (ASCS) on staff, who have taken and passed the NADCA certification examination. NADCA members must sign a code of ethics to protect the consumer and follow NADCA standards for cleaning.
For a comprehensive post cleaning consumer checklist, visit the EPA. EPA recommends you show this checklist to the service provider before work begins. After completing the job, the service provider should show you each component of your system to verify that the job was performed satisfactorily.
For more information, you may also want to contact: North American Insulation Manufacturers Association (NAIMA) 703-684-0084