Duct cleaning? Fret no more.
"It should be on an as-needed basis," says Laureen Burton, a chemist/toxicologist within the indoor environments division of the Environmental Protection Agency. "There still is not a lot of data that supports any real benefits from having ducts cleaned, under most circumstances."
In 1997, the EPA issued a comprehensive publication, "Should You Have the Air Ducts In Your Home Cleaned?" (epa.gov/iaq/pubs/airduct.html). There was a need for it then because some air duct cleaning companies were touting the health benefits of cleaning.
"And the data just doesn't support it, whether (cleaning) was good or bad," Burton says. "No data says it's really beneficial, nor does it say it creates more havoc."
The EPA is currently updating the document, primarily because it is 14 years old.
"But it turns out," Burton says, "the need for updating has to do more with new ways of getting information out. The old PDF on a computer is not the only way to get information out today. The information itself, very little has changed. When I looked up studies, I found there have been couple more done, but they have the same information. They don't see any great need, or harm, in cleaning ducts."
Even John M. Schulte, the executive director of the National Air Duct Cleaners Association (nadca.com), preaches caution. He says to make sure your air handling unit has a quality filter, one recommended by the manufacturer, and "change it religiously" every two months.
"Using a good filter and changing it regularly are definitely good things to do," says Schulte, whose trade organization developed the first standard for the industry, in 1992, and has about 1,000 member companies in 30 countries. "That's why the manufacturers put them on in the first place. But if you look at filters, they're not 100 percent. . . . Some filters aren't too good. You can buy them for less than a dollar at the hardware store. Those are referred to as bowling ball cleaners in the industry. They'll catch things the size of a bowling ball, but not much else."
But when should a duct-cleaning company be called?
Schulte says it depends on the area of the country you live in or if you're in a construction area.
"We recommend having your system inspected every year or two years. Look in the ductwork, look in the actual unit itself," he says.
The EPA agrees there are times when a duct cleaning is in order.
"If you do look in your ducts and, say, vermin got in there, or they do an inspection and it's really bad, or you see mold growth, then you need a cleaning," Burton says.
Those problems, she points out, are the result of other situations that need immediate correction. Find out how the critters are getting into the ducts and block them, If there's mold, the entire system needs to be cleaned and the source of moisture identified.
But mostly, keep your home as dust-free as possible, have your furnace or air conditioning unit monitored, and use the most efficient filter available, changing it regularly.
As with other home services, do your homework before hiring anybody to look over the system. Get three or four estimates. Check with neighbors for a recommendation. And don't jump at those cut-rate companies that promise a lot for a little.
"They put those coupons out – you get them in the mail all the time – whole house duct cleaning, $49.95," Schulte says. "This is definitely an industry where you get what you pay for. . . . It takes at least 3-4 hours; sometimes it takes longer than that. If you think you're going to have two people come out, with their equipment, using their gas, all for $49.95, that's unbelievable."