There's a debate raging on the merits of duct cleaning versus duct sanitizing. Some companies will advertise the two services as if they're the same thing, but there's an important separation that consumers should be aware of, lest they risk causing permanent damage to their ductwork that is serious enough to warrant a full replacement.
"Duct cleaning in a residential home is definitely a no-no. It's a controversial subject because, in the industry, a lot of people want to do it because there's money to be made" says David Russell, the President of Action Air Conditioning. "You can't run a cleaning machine through a duct unless it's a metal duct. Now, if it's a metal duct, like the commercial types, absolutely you can. Because it's metal, and you can't hurt metal."
Before you call in a professional to handle your duct cleaning, make sure you know what type of ductwork is in your home, otherwise the process could end up costing you big.
In Florida, most residential homes use a fiberglass duct system. Scrubbing or scraping these ducts can destroy them, leading to tiny pieces of glass being blown all over the home. People who have fiberglass ducts cleaned with machines that sweep away dirt and grime risk breaking the "vapor barrier", which will result the homeowner breathing in glassy bits once the job is done.
"What duct board is made of is compressed glass, and then a clear coat?shield is sprayed on it—like a clear paint," David says. "And if you rub it and scrub it, you break that off, and then all of a sudden you start to get little pieces of this dusty stuff all over your house. Well, what's happening is you broke the vapor barrier, and now you're getting little pieces of glass blown out through your duct system, and there's nothing we can do other than to replace them at that point. The damage has already been done."
David says he is approached by new customers all too frequently who recently had a duct cleaning and are now noticing their furniture is covered in shiny dust. As for what should be done to remove dust and dirt from ductwork, he actually recommends that people forget about it and focus on sanitization.
"It's like a pool; you throw chlorine in there, and it kills the bacteria. We spray the ducts, which kills the germs," says David. "Dirt in the duct won't hurt you - what hurts you is the microorganisms that live inside the ductwork. What I recommend people do is kill that bacteria; then keep your filters clean and the dust isn't a problem. The dirt would have never gotten in there in the first place if people remembered to use a high-quality filter."
If homeowners want to properly clean out their fiberglass ducts, it can be done for a premium price. The process involves using a machine to clean and vacuum the ducts, which will likely damage the clear coating that seals the fiberglass.
After this, the duct must then be cut open, re-sealed and taped back together. This process is so labor intensive that it's actually cheaper for home owners to replace all of their ductwork, meaning that a full cleaning is something most may want to avoid. Remember that dirt trapped in your system isn't likely to cause health concerns.
If your filters are changed regularly and your ducts are sanitized, then the air quality in your home shouldn't be negatively affected by your HVAC system - and you won't be inhaling fiberglass remnants either, since sanitizing won't destroy anything except germs.