Today we discuss a question which our team gets often. What is the best way to clean air ducts? This question will be answered, and some incorrect methods used to clean ducts will also be discussed. Cleaning the air ducts on a central air system consists of these key steps. Making access into the air ducts, placing the entire air duct system under negative pressure, loosening the dirt and debris from the air duct interior and into the negative pressure collection unit, and the application of antimicrobial sprays if applicable. Over the years, our team has encountered different methods of cleaning being used.  We have seen issues with these cleaning systems and tactics. Lets take a minute to review these methods.

* Rotating Brush On The End Of A Vacuum Hose*

This is a process of cleaning air ducts by which a hose with a high speed spinning brush on the end, is shoved into the vent or return. The hose is pushed through the duct as far as it will reach.  This process is repeated through every vent and return to clean the air duct system, however, we see several drawbacks with this method of cleaning. First, a high speed spinning brush can catch (frequently encountered), construction material in its bristles. Debris such as nails, staples, drywall cutting blades, ect. are now being slung around at high speed with the brush head. This debris has the potential to cause major damage to flexible and fiberboard ducts, before being noticed by the operator.  Getting the spinning brush caught onto the electrical wires found in return ducts is another consideration. Bulky brush on hose equipment is also ineffective at maneuvering the bends often found in air duct systems. If stuck at a bend and pushed to hard to clear the turn, damage to the air ducts is also a real possibility. Finally there is the lack of vacuum power, which is usually the equivalent of a shop vac. This equipment can not properly prevent recontamination of already cleaned ducts, completely remove all material loosened during air duct cleaning, and certainly cannot be relied on to effectively clean the large plenums/ trunk lines of an air duct system.

* Vacuum Hose And Blown Air*

This cleaning method relies on pushing a 1 1/2"-2" vacuum hose into the vent or return. Next an air line is pushed through the duct in hopes of pulling the material back into the vacuum hose. As with the last method of cleaning, we run into the issue of insufficient vacuum power. The small diameter hose using a shop vac. style vacuum, or carpet cleaning machine cannot offer enough suction to properly pull all loosened material from the air duct system. And again, we run into the problem of not enough vacuum power to properly clean the large duct plenums, and cross contamination due to the lack of a constant negative pressure pull. Second we have the problem of incorrectly and ineffectively, loosening the dirt and debris from the duct sidewalls. Compressed air alone will remove some build up, however it doesn't provide adequate results on systems with moderate to heavy build up, or hard stuck on dirt and debris typically  found in air duct systems.

* Negative Pressure Cleaning*

The method used by Specialty Air Ducts is the negative pressure cleaning, which provides the best results and is known to produce the best results in the air duct cleaning industry. First the entire air duct system is placed under negative pressure/ constant vacuum pull, at a location near the furnace or air handler, using a Power Vacuum system. Next pneumatic whip agitators are sent through the vent and return branches one by one. The pneumatic whip system creates a brushing action, while not using a conventional brush with bristles, and doesn't spin while doing its job. Instead it relies on pneumatic pressure to power tentacles on a very slim and semi flexible rod which can be snaked through the entire length of  most all air ducts. This loosens all material while blowing the dirt and debris into the negative pressure stream for collection. The process is repeated through all vents and returns, and an antimicrobial, sanitizer, or deodorizer may be applied to the air duct system. All material collected in the plenums will be agitated and pushed or pulled into the negative pressure collection unit. Included in our cleaning methods is hand brushing and vacuuming of all vent and return covers or diffusers. All access points created to complete the service, are to be sealed air tight upon completion of the cleaning.

Our company has heard of other methods but to keep the article brief we covered the most commonly used processes. We understand choosing an air duct cleaning service can be a confusing task. Not all companies are cleaning air ducts using the same methods or equipment. Whether you are planning to hire us for the cleaning or are just gathering information, we hope that this article has been informative. Our purpose for answering this frequently asked question is to enlighten consumers on the proper method for air duct cleaning. Our goal is to help you make an informed decision when hiring an air duct cleaning company, and for you to have actual data by which to compare when shopping for this service.