Air Ventilation Duct Cleaning.

Allergies?  Unexplained Chronic Illnesses?  Hopefully not. But ...

Like regularly changing the batteries in you smoke detector, a periodic home inspection of you heating and cooling system is always a good idea.  

 Aesthetically changing the vents, registers and grilles because of room dynamics is one thing, but watch out for the obvious.  Register or "damper" failure due to dust, grit or rust should certainly be looked into.

I hope the information and links below will help you understand and be aware of the "ins and outs" of your heating and cooling system.

A Typical Residential Heating and Cooling System

You should consider having the air ducts in your home cleaned 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. There are several important points to understand concerning mold detection in heating and cooling systems:

• Many sections of your heating and cooling system may not be accessible for a visible inspection, so ask the service provider to show you any mold they say exists.
• You should be aware that although a substance may look like mold, a positive determination of whether it is mold or not can be made only by an expert and may require laboratory analysis for final confirmation. For about $50, some microbiology laboratories can tell you whether a sample sent to them on a clear strip of sticky household tape is mold or simply a substance that resembles it.
• If you have insulated air ducts and the insulation gets wet or moldy it cannot be effectively cleaned and should be removed and replaced.
• If the conditions causing the mold growth in the first place are not corrected, mold growth will recur.

Ducts are infested with vermin, e.g. (rodents or insects); or

Ducts are clogged with excessive amounts of dust and debris and/or particles are actually released into the home from your supply registers.

Other Important Considerations...

Duct cleaning has never been shown to actually prevent health problems. Neither do studies conclusively demonstrate that particle (e.g., dust) levels in homes increase because of dirty air ducts or go down after cleaning. This is because much of the dirt that may accumulate inside air ducts adheres to duct surfaces and does not necessarily enter the living space. It is important to keep in mind that dirty air ducts are only one of many possible sources of particles that are present in homes. Pollutants that enter the home both from outdoors and indoor activities such as cooking, cleaning, smoking, or just moving around can cause greater exposure to contaminants than dirty air ducts. Moreover, there is no evidence that a light amount of household dust or other particulate matter in air ducts poses any risk to health.

EPA does not recommend that air ducts be cleaned except on an as-needed basis because of the continuing uncertainty about the benefits of duct cleaning under most circumstances. If a service provider or advertiser asserts that EPA recommends routine duct cleaning or makes claims about its health benefits, you should notify EPA by writing to the address listed at the end of this guidance. EPA does, however, recommend that if you have a fuel burning furnace, stove, or fireplace, they be inspected for proper functioning and serviced before each heating season to protect against carbon monoxide poisoning. Some research also suggests that cleaning dirty cooling coils, fans and heat exchangers can improve the efficiency of heating and cooling systems. However, little evidence exists to indicate that simply cleaning the duct system will increase your system's efficiency.

If you think duct cleaning might be a good idea for your home, but you are not sure, talk to a professional. The company that services your heating and cooling system may be a good source of advice. You may also want to contact professional duct cleaning service providers and ask them about the services they provide. Remember, they are trying to sell you a service, so ask questions and insist on complete and knowledgeable answers.

Consumer Checklist
	Learn as much as possible about air duct cleaning before you decide to have your ducts cleaned by reading this guidance and contacting the sources of information provided.
	Consider other possible sources of indoor air pollution first if you suspect an indoor air quality problem exists in your home.
	Have your air ducts cleaned if they are visibly contaminated with substantial mold growth, pests or vermin, or are clogged with substantial deposits of dust or debris.
	Ask the service provider to show you any mold or other biological contamination they say exists. Get laboratory confirmation of mold growth or decide to rely on your own judgment and common sense in evaluating apparent mold growth.
	Get estimates from at least three service providers.
	Check references.
	Ask the service provider whether he/she holds any relevant state licenses. As of 1996, the following states require air duct cleaners to hold special licenses: Arizona, Arkansas, California, Florida, Georgia, Michigan and Texas. Other states may also require licenses.
	Insist that the service provider give you knowledgeable and complete answers to your questions.
	Find out whether your ducts are made of sheet metal, flex duct, or constructed of fiber glass duct board or lined with fiber glass since the methods of cleaning vary depending on duct type. Remember, a combination of these elements may be present.
	Permit the application of biocides in your ducts only if necessary to control mold growth and only after assuring yourself that the product will be applied strictly according to label directions. As a precaution, you and your pets should leave the premises during application.
	Do not permit the use of sealants except under unusual circumstances where other alternatives are not feasible.
	Make sure the service provider follows the National Air Duct Cleaning Association's (NADCA) standards and, if the ducts are constructed of flex duct, duct board, or lined with fiber glass, the guidelines of the North American Insulation Manufacturers Association (NAIMA).
	Commit to a preventive maintenance program of yearly inspections of your heating and cooling system, regular filter changes, and steps to prevent moisture contamination.