Air duct cleaning is a misnomer. In actuality, they should clean the entire HVAC system. Failure to clean all components of the system can cause the decontamination of the entire system, thus minimizing the benefits of cleaning.
Just as you wouldn’t clean only half of your living room floor, you also would not want to clean only part of your HVAC system. NADCA recommends cleaning the entire HVAC system, including the following components:
- Air ducts
- Drain pan
- Air plenum
- Blower motor and assembly
- Heat Exchanger
- Air filter
- Air cleaner
Breaking Contaminants Loose
Properly cleaning, HVAC systems requires removing the sources of contamination. Source removal begins with the use of one or more agitation devices designed to loosen contaminants from the surfaces within the heating and air conditioning system. Examples of agitation devices include: brushes, air whips and compressed air nozzles or “skipper balls.” Agitation can also be achieved through hand-brushing or contact vacuuming.
Collection of Contaminants
During cleaning, we place the entire HVAC system under continuous negative pressure (a vacuum) to prevent the spread of contaminants. The continuous negative pressure allows very fine particles to be removed from the system as they become airborne, ensuring that it does not release these particles into the living space when the system is turned on after cleaning. This negative pressure also serves to extract the loosened contaminants, which are collected and removed from your home.
HVAC system cleaning is not a complex process, but each job is unique. Where possible, we should make access to duct interiors through existing openings such as supply diffusers, return grills, duct end caps, and existing service openings. Cleaning technicians may need to cut access holes in the Ductwork to reach inside with various cleaning tools. The creation of these service openings, and their subsequent closure, requires craftsmanship and professional skills.
There is a wide variety of equipment available to HVAC cleaning professionals. Both truck-mounted and portable vacuums can be used to stop the spread of contaminants and get the system cleaned to the NADCA Standard.
Antimicrobial chemicals include sanitizers, disinfectants and deodorizers that can be applied to nonporous surfaces in HVAC systems to address microbial contamination and help control odors. Only chemicals registered with the United States Environmental Protection Agency (EPA) can be used. These products should only be considered after mechanical surface cleaning has been performed and if the need for such treatment has been deemed necessary. Review the NADCA White Paper on Chemical Applications in HVAC Systems for more information.
HOW DO I FIND WHERE MY DUCTS ARE LEAKING?
The first step to stopping leaky ducts is to locate the source. The best place to start is with any exposed ductwork you can see. If you have removable tile ceilings (usually found in finished basements), remove the tiles and look for ductwork to inspect. Look for poor connections at joints, holes caused by wear and tear, and loose, crushed, or tangled ductwork to find the most likely culprits.
If you don’t find any obvious signs of leakage, use the smoke test to locate problem areas. Turn your unit to its fan setting and light a stick of incense (or a candle). Pass the smoke from the incense over the exposed ducts in your home, starting with the places where your ducts connect to the main unit and the areas where two ducts are joined. If the smoke is blown away from the joint or pulled into it, you are experiencing duct leakage.
HOW DO I FIX THE LEAKING DUCTS?
Once you locate where your ducts are leaking, there are some simple solutions for fixing the problem.
- Seal your joints. Seal any holes, loose connections, or leaky joints with duct mastic sealant or metal duct tape. Unlike traditional, cloth-backed, rubber duct tape, these sealants are long-lasting and provide the sealing strength you will need to stop leakages long-term.
- Inspect your registers and vents. Are they well-connected? If not, tighten your wall vents and seal any gaps between the duct system and register connections to ensure you are not losing valuable air. Creating tight connections where your system delivers air to your rooms will help you avoid duct leakage and keep your system running efficiently.
- Insulate your ductwork. Wherever possible make sure your ductwork is insulated, especially if it’s in unconditioned areas like an attic or garage. Insulating your ductwork will reduce opportunities for air to escape your system and provide better HVAC system efficiency, saving you hundreds of dollars over the life of your system.
WHEN DO I NEED AN HVAC PRO?
If you follow these tips and your energy bills are still higher than average, or if you just don’t feel comfortable crawling through your house looking at your ductwork, use the “Find A Contractor” link on HVAC.com to have our team connect you with a trusted, licensed local HVAC professional from our contractor network that is focused providing you the best customer experience possible.