Air duct cleaning: Know the facts before making a hire

Air duct cleaning: Know the facts before making a hire
The inside of a silver air duct before cleaning

The inside of a silver air duct before cleaning

Air duct cleaning has been popularized as a solution for alleviating allergies and removing other airborne contaminants. While this may be true in certain circumstances, it is definitely not the case in many homes or businesses. A few simple steps and some basic indoor air quality knowledge are the only requirements needed to make an informed decision for your family or business.

Contamination levels vary greatly in ducting from light/none, to heavy dust, to mold growth. Light dust is nothing to be concerned about, according to the EPA. If mechanical components, such as the blower wheel, and/or evaporator coil, are impacted with debris, then the cleaning of said components will allow more air to flow through the ducting. This action provides an opportunity for previously deposited debris to be released in the ducting under the increased air flow. In this case, duct cleaning may be recommended.

Visual inspection

A visual inspection is the only way to verify whether air duct cleaning may prove useful. The air inspection system should not only include an internal inspection of the ducting, but the blower wheel (the fan that moves the air through your heating and air conditioning system), the plenums, and the evaporator coil.

Simply peering into the air duct from the register/vent opening will give you the least amount of information about the duct system contamination levels, and merely counting the number of register/vent openings will only lead to job price estimations, rather than initially identifying any real indoor air quality problems.

Quality inspections should include real pictures of the interior of your ducting. If the inspection reveals microbial growth inside the ducting, it should be replaced. The problem that created the environment for the mold growth will also need to be corrected, to prevent recurrence.

Know your ducting

Sheet metal ducting: In most cases, there is no microbial growth in sheet metal ducting, as the galvanizing treatment to prevent rusting of the metal is a good antimicrobial surface. The exception, however, is when amounts of debris in the ducting build to significant levels and become breeding grounds, without contacting the sheet metal.

Flex duct: Most types of flex duct do not inhibit microbial growth, so replacements should be done if they are contaminated with mold.

Chemicals: Antimicrobial treatments will not correct the problem, nor resolve the issue short-term, and there are no registered products with the EPA that are considered sanitizers or disinfectants. The issue is with surface coverage, as no one can guarantee a 100 percent embodiment inside air ducts for complete sanitization.

Furthermore, antimicrobial chemicals cannot be applied to insulation or other porous materials, only non-porous surfaces. Last, the contractor applying the antimicrobial can also be restricted by state regulation. For example, the State of Texas requires a licensed air conditioning contractor to apply any antimicrobial into ducting; any other contractor applying an antimicrobial is in violation of state law.

Hire a professional

The best choice a homeowner or business can make for the evaluation and cleaning of air duct systems is hiring a licensed air conditioning/heating company. Air duct cleaning equipment is commonly purchased by carpet cleaners, or start up air duct cleaning businesses, having little or no experience in air conditioning/heating, or of proper air system cleaning methods. Proper training is available but some repair people do not always take the training.

Simply put, just cleaning air ducts will not correct problems, if any exist to begin with. Most non-air conditioning companies will simply remove the vent on the ceiling or floor, and get as far as they can reach. Unfortunately this will not reach 100 percent of the ducting, nor clean the plenum(s), blower wheel, or evaporator coils.

After this kind of so-called duct cleaning, the air conditioning system is turned on, and with it, a swarm of dust/debris may be blown out into the livable/conditioned space. Without a complete air system cleaning, it is very likely the person purchasing the service may have made things worse in the home or business, not better.

Buyer beware

A $69 or $120 whole system cleaning is a bait and switch program. Simply looking at the reality of the work that needs to be accomplished, and the basic business operation, will verify this. There should be a list of business expenses for proper business operation, to the equipment, and the technician. The average drive time to a job is 25 minutes.

The equipment must be unloaded, and the vents removed or sealed. Then the cleaning process starts, followed by the completion, by reinstalling registers. The equipment must then be loaded, and the air conditioning system turned on to verify it still operates. Hopefully the home’s air ducts are left in as good or better condition, upon completion.

About this Experts Contributor: Scott Peterson has been in the indoor air quality and energy efficiency industry since 1993. He represents Diamond Quality Services, providing high quality air cleaning, heating and cooling services to the Dallas area since 2008. You can learn more by visiting the company website.

As of August 6, 2014, this service provider was highly rated on Angie's List. Ratings are subject to change based on consumer feedback, so check Angie's List for the most up-to-date reviews. The views expressed by this author do not necessarily reflect those of Angie's List.

More Like This

Best Fort Worth Contractors of 2010

A HVAC provider, deck and fence restorer and glass company lead by example and top this year's Best of Fort Worth.


What is Angie's List?

Angie’s List is the trusted site where more than 3 million households go to get ratings and reviews on everything from home repair to health care. Stop guessing when it comes to hiring! Check Angie’s List to find out who does the best work in town.

Local Discounts

Daily deals up to 70% off popular home improvement projects from top-rated contractors on Angie’s List!