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What Happens During an Air Duct Cleaning?

Posted by Kelly on Mar 24, 2015 11:38:00 AM

Air duct cleaning

If you have a mailbox, you’ve probably gotten advertisements, flyers and coupons for air duct cleaning. After seeing some of the before-and-after pictures, you may have wondered if it’s necessary for you house, and if so, if the company advertised is a reputable one. We’re here to tell you what happens during an air duct cleaning so you can make the best decision for your home.

Should I get my ducts cleaned?

Deciding IF you should even get it done is a good place to start because ductwork should be cleaned only “as needed” in residential homes. Basically that means unless they are really dirty, there is no need to clean them frequently. The Environmental Protection Agency (EPA) says that you should consider getting your air ducts cleaned if:

  • There is visible mold growth inside ducts or on other components of your heating and cooling system. 
  • There is a rodent or insect infestation (or dead vermin in the ducts) 
  • The ducts are clogged with dust and debris or particles are released into the home from your heat/cooling registers.

How often will it need to be cleaned?

“A system where the filter has been neglected or with a loose fitting filter may need to be cleaned very 5 to 10 years,” says Keith Hill, manager, technical support, from Minnesota Air. “A system with a good filter that fits well and is changed regularly should need duct cleaning every 15 or 20 years.”

Keith says ‘fitting well’ means that very little air is able to pass by the filter. Bypassed air brings bypassed dirt with it, so it’s important to get a filter that fits snugly.

“To prevent bypassed air, I recommend using a quality filter with foam gaskets around the perimeter if you can find one that fit your furnace,” says Keith. “One trick that I’ve used for years on loose fitting filters is to buy a few rolls of adhesive backed soft foam weather-stripping and wrap the edge of the new filter before you install it.”

What is accomplished during a professional air duct cleaning?

There are multiple ways to clean ductwork, but all companies should remove dust, dirt, and debris from the surfaces of your air ducts, registers, grilles, and air passageways of the evaporator coil and furnace.

“They should also be cleaning the coil drain pan and condensate drain line,” says Keith. “Accessories such as humidifiers, air purifiers, heat recovery ventilators, and UV lamps should be inspected and cleaned as well.”

All duct-cleaning companies should be using a vacuum system to remove the loosened debris and capture it. Some companies use a rotating brush, others use high-pressure air injected through holes in the ductwork to get the job done. Both methods work.

How do I find the right company to do the work?

Choosing the right company to do the cleaning is crucial, because if a service provider isn’t properly trained, it can actually do more harm and cause damage to your heating/cooling system and ductwork. No one wants to pay for repairs or have their energy costs go up after paying to get something done that is supposed to improve efficiency and longevity of your HVAC system.

The EPA recommends all duct cleaners follow National Air Duct Cleaners Association (NADCA) standards. To find a professional certified by the NADCA, click here. The NADCA also has a helpful checklist for consumers before hiring an HVAC cleaning company.

Do I need to move furniture?

The technicians need access to all registers, so if there is furniture in front of a register it will need to be moved. Ask the company you hire beforehand to see if it’s something the technicians do, or something the homeowner needs to do.

How long does it take?

Keith says it should take 3-7 hours for a system cleaning, depending on the system’s size and components. He says the variances in time depend on the size of the home (large home = more ductwork), the number and type of accessories, and the ease of access the technician has to ductwork and components.

What happens if I don't get one done?

Don’t ignore a dirty duct system!

“Besides the discharge of airborne crud coming out of the vents, the system efficiency is greatly reduced, and worst of all you may be reducing the life expectancy of the equipment,” Keith says. “The system needs adequate airflow to operate properly.”

Looking to have your HVAC cleaned up? Check out to find a Factory Authorized Dealer near you.

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Topics: Home Maintenance