February 18, 2004
by By Mike McClintock,
Washington Post
February 18, 2004
In houses that produce voluminous amounts of dust and mold, ducts might need cleaning every few years. But in most homes with reasonably modern furnaces and air conditioners, where filters are replaced regularly, a professional cleaning is rarely, if ever, required.
If no one in the household suffers from allergies or unexplained symptoms or illnesses, and if a check under the registers does not reveal large deposits of dust or mold, cleaning is probably not necessary, according to the EPA. You should consider having air ducts cleaned if there is a noticeable buildup of dirt and dust despite regular filter changes, and if there is substantial and visible mold growth inside the ducts even though the appliances are well maintained.
The cleaning decision also can be affected by the type of ducts you have: traditional sheet metal, nonmetal ducts made of fiberboard, or any type of duct (often flexible ductwork) that has some type of internal liner.
Though there are disagreements, the EPA says current research indicates that all types of ducts support microbial growth to approximately the same degree. But there are some distinctions. One is that moisture can be trapped in some insulated duct systems, which have to be kept reasonably dry to retard mold growth. This is not much of a problem in bare metal ducts that have no liner or porous material to trap moisture.
It's also easier to treat mold contamination on bare sheet metal than on other types of ducts. Contractors can use an EPA-registered biocide (often called a sanitizer) on bare metal.
But once a fiberglass duct liner is contaminated with mold, cleaning is not sufficient to prevent regrowth, according to the EPA. One obvious reason: No products are currently EPA-registered as biocides for use on fiberglass duct board or fiberglass-lined ducts. Both the EPA and the Washington-based National Air Duct Cleaners Association (NADCA) recommend replacing wet or moldy fiberglass duct material.
Professional cleaning services
The services to watch out for are called blow-and-go in the trade. Contractors who provide them might not be licensed, probably are not members of any trade association and often spend less than an hour in your house.
Sales pitches for blow-and-go work often include sweeping but unsubstantiated claims about the health benefits of duct cleaning, claims of EPA certification or approval (both bogus) and recommendations for annual duct cleaning, which is unnecessary, as part of your annual appliance service.
Worse yet, contractors using inadequate vacuum collection systems and short-cut cleaning procedures can cause more problems than they solve. According to the EPA, these substandard jobs can release more dust, dirt and other contaminants into the air than simply leaving the ducts alone. Cost and time estimates vary because of the different sizes of houses and complexities of duct systems. But the EPA says that a professional cleaning should cost from $450 to $1,000 and take four to eight hours in a typical three- or four-bedroom house.
Proper procedure, according to NADCA, is to place the system under negative pressure with a powerful vacuum and insert various brushes and cleaners into the ducts to dislodge debris, which flows to the vacuum. NADCA guidelines allow both vacuum equipment that exhausts particles outside of the house, and inside-exhaust systems fitted with HEPA filters.
Duct surfaces can be brushed and directly vacuumed. Soft-bristled brushes must be used for fiberglass duct board and sheet metal ducts lined with fiberglass. Flexible ducts can also be cleaned using soft brushes, but it might be more economical simply to replace them.
Sealants and sanitizers
Duct sealants are designed to coat duct surfaces and prevent dust and dirt particles from being released into the air. But there are some flaws in the concept.
One is that coatings sprayed into an operating duct system do not completely coat the duct surfaces. Another is that sealants might affect the fire-retarding characteristics of fiberglass-lined ducts and could invalidate the manufacturer's warranty. Yet another is that aging sealants could detach from the ducts and contribute to the amount of particles that need to be cleaned.
Sealants should never be used on wet duct liners or as a stopgap measure to cover actively growing mold or to encase debris in the ducts.
Because of these and other questions about safety and overall effectiveness, most organizations concerned with duct cleaning do not currently recommend the routine use of sealants in any type of duct. The organizations include the EPA, NADCA, the North American Insulation Manufacturers Association (NAIMA) and the Sheet Metal and Air Conditioning Contractors' National Association (SMACNA).
On the other hand, sanitizers containing chemicals that retard microbial growth -- mainly mold -- can be applied to the interior surfaces of ducts. However, most duct systems do not require them. If yours does, the system should be thoroughly cleaned before the sanitizer is applied.
Bear in mind that while there are EPA-registered biocides (sanitizers) recommended for bare metal, there aren't any recommended for duct systems with porous surfaces such as fiberglass.
For more information, contact:
Alan L. Wozniak, CIAQP
(800) 422-7873 ext. 802
By Mary F. Pols
Twenty-three years in the same house in Lafayette, California, and Bob Keagy had never gotten his air ducts cleaned.
Sure, he'd changed the filters a couple times. But his heating and cooling system had been chugging along pretty much untouched until the recent winter day when he opened his door and ushered in technicians Dean O'Loughlin and Mike Walker of Pleasant Hill-based Air Duct Cleaning Specialists.
With them came two enormous machines, a high efficiency particulate arresting (HEPA) air filter and a powerful vacuum, which they parked in a hallway while they explored Keagy's house. With 17 ducts throughout the rambling two-story house, O'Loughlin and Walker were looking at least a five-hour job. And Keagy was looking at about an $800 bill, a price he was more than willing to pay if it meant improving his wife's terrible allergies.
His reason for trying air duct cleaning is one of the most common in America.
Our increasingly phobic society, which scrubs its hands with anti-bacterial soap, bathes its chickens thoroughly before cooking and frets about pollution, both inside the home and out, is flocking to air duct cleaning. Roughly 10 years old, it is one of those businesses that materializes out of nowhere and suddenly seems like a necessity to thousands.
The promise is that the process of using giant vacuums and brushes to scour out the ducts and filters of forced-air heating system will remove gallons of dirt, dust and animal dander from the home. It's alleged to help allergy and asthma sufferers, remove smells and make energy systems run more efficiently.
But there's a debate among scientists about how valuable duct cleaning actually is. Is it a fad that will disappear in a few years, or a practice that will someday be as common as getting the house painted? What is certain is that 10 years ago, it is unlikely it ever would have occurred to Keagy and his wife to have it done. The industry was just getting rolling.
If anyone ought to know about the birthplace of the contemporary air duct cleaning craze, it's Tim Hebert, the president of the Wash., D.C.-based National Air Duct Cleaners Association. His theory is that it all started in July 1976, in a hotel in downtown Philadelphia. The American Legion was holding a statewide convention in the city, when suddenly the legionnaires mysteriously began falling ill with pneumonia. More than 180 people got sick and 29 died.
The source of the pneumonia was a strain of bacteria that was unrecognized at the time, and which was later dubbed legionella pneumophilia. It had spread through the hotel's cooling system, flowing into every room in the hotel through the air conditioning.
Hebert credits the outbreak with spurring public interest in indoor air pollution, an entirely new concept to a generation of Americans who had grown accustomed to the joys of air-conditioned buildings in the summer and cozy, air-tight interiors in the winter. What had seemed like sensible energy-efficiency in the 1970s suddenly had a bad side. People started talking about "sick buildings".
At the time of the Legionnaires Disease outbreak, industries had already been using basic air duct cleaning techniques for decades, Hebert said. But the practice was about keeping machines running smoothly, not health.
"Maybe you had a manufacturing process, like say, a cotton thread plant", he said. "You can imagine all the dust in the air. But they'd be concerned from an energy efficiency standpoint, rather than from a health standpoint".
About 14 years ago, Hebert did a favor for a friend and found himself roped into an air duct cleaning job. Or as he refers to it, "duct cleaning". Zipped into a cover-all, he helped his friend jam what amounted to not much more than a vacuum cleaner down a few ducts.
The equipment he used seemed lousy, but the concept seemed solid. For a guy who studied chemistry in college, and who was casting around for a career, this job, while certainly lacking in glamour, seemed like it had some potential. He relocated to a tiny town in south Georgia, just far enough away from his friend so that there wouldn't be competition issues, and set up his own company. He quickly discovered that his instincts were right. The industry was taking off.
Meanwhile, to his north, in Wash., D.C., one of the Environmental Protection Agency's indoor air pollution specialists, a guy named Bob Thompson, noticed that companies were beginning to offer residential duct cleaning. He had an inkling that he was witnessing the birth of a craze.
"I saw this coming all along", Thompson said. "I knew this would be one that would get loose and people would grab at it as a quick fix".
When Thompson talks about duct cleaning, he does so in an unofficial capacity. That's because the EPA has no written policy on duct cleaning. The agency doesn't condemn residential duct cleaning outright, but it certainly doesn't condone it either. Thompson said the reason is that no major health studies have been done on the practice, so there is no proof that duct cleaning is even necessary. In its report, "Should You Have the Air Ducts in Your Home Cleaned?" which is available on the Web, the EPA cautions that, "Duct Cleaning has never been shown to actually prevent health problems". It advises consumers to proceed carefully before signing up for a cleaning, because there are unethical vendors.
Thompson said he would consider getting his ducts cleaned if he lived in an old house, but that personally, he would prefer to spend the money on other home maintenance, such as checking for radon.
"My own opinion is, it's over sold and over marketed", Thompson said. "Definitely, there are times when it can be very valuable, but that is very seldom. Yet it is one of the most sold services and it is so heavily advertised, that it must be a good profit-maker".
"Like anything else, it's buyer beware", he added.
The EPA and the National Air Duct Cleaners Association both say duct cleaning should not be an annual event. If the job is done right, it should last a long time, Hebert said.
"A thorough HVAC cleaning should not have to be performed more than every five to seven years", he said.
Hebert is acutely aware of the proliferation of fly-by-night duct cleaners, who make promises they can't or won't deliver, attach huge fees to their advertised bargain rates and take consumers for a ride. He said a lot of that has to do with the nature of the job.
"Duct work is out of sight, out of mind", he said. "If you pay someone to paint your house, you can pretty much walk by and tell if they did their job or not. You can't do that with ducts".
Unless of course, you are Bob Van Gelder. Last fall, Van Gelder, who owns Air Duct Cleaning Specialists, the company Keagy chose, decided to do a little test. He had been seeing all the advertisements for cheap air duct cleaning — $79! For Your Whole House!" — and frankly, it was hurting his own business. He has been in the business since 1979 and all of a sudden, customers started calling up and telling his salespeople that his prices — which start at $335 — were too high.
So he booked an appointment with one of the companies he had seen advertising bargain rates.
The hapless air duct cleaner from the $79 company, which Van Gelder won't name publicly, was an hour late. He'd gotten lost. He was driving a small truck with a camper shell, no logo painted on the side. Van Gelder checked out the equipment in the back. There was something called a flapper, that spins around and knocks the junk off the sides of ducts. Then there was a rudimentary vacuum. This was 1980s equipment as far as Van Gelder was concerned. Useless.
"It was like a Sears shop vac", Van Gelder said contemptuously. "The only thing he had that was impressive was an itemized sheet with additional prices on it, all the add-ons they bill you for".
He didn't bother having the work done. He sent the cleaner on his way with $10 in his pocket.
After Van Gelder became aware that the too-good-to-be-true companies, as he likes to call them, were affecting his sales, he instructed his salespeople to respond to questions about their pricing with this preamble: "We're aware that there are a lot of attractive misleading prices out there".
But that's not much of a weapon against what Van Gelder says can be out-and-out fraud.
Hebert, the cleaning-association president, knows that legitimate businessmen need protection from the too-good-to-be-true companies. But he says his nonprofit organization doesn't have the money or the staff to do any actual policing of the industry. Since the EPA doesn't regulate air duct cleaning, the lone means of controlling bad business practices is through the Better Business Bureau.
Interest in air duct cleaning industry has run high lately at the Better Business Bureau. Pat Wallace, president of the Bay Area branch of the national organization, said he spotted ads last summer that seemed to make grandiose promises about the services available. He put the topic on his to-do list.
In the meantime, the bureau's Cincinnati branch was working on a complaint about the advertising practices of one company, Florida-based United Air Comfort, also called United Restoration. They had received complaints about bait-and-switch tactics — where what was supposed to be a $59 job ended up costing much more because of add-ons. The ads also made claims about the health benefits of duct cleaning that couldn't be substantiated.
Furthermore, the pricing structure seems to change from ad to ad and week to week, said Jocile Ehrlich, the president of the Cincinnati Better Business Bureau.
"It's very difficult for the consumers to get a handle on what is a good deal here, what is a reasonable deal, because the pricing is all over the place", she said.
Ehrlich said United Air Comfort has altered its ads somewhat to rectify the problems, but that the Better Business Bureau is still not satisfied that the ads are completely accurate and not misleading.
"We're slowly getting there", she said.
In a very brief phone interview, United Air Comfort spokesman Ian Birch said his company changes pricing "like any other company", and that the debate with the Better Business Bureau is behind them.
"Their issues were all addressed and answered some time ago", Birch said, before hanging up.
United Air Comfort has also gained some notoriety in the industry. Asked about United Air Comfort, Tim Hebert gave a long, hearty laugh.
"That's my only comment", he said. "You can say I laughed".
Apparently, the rating hasn't hampered United Air Comfort's business completely. The company is still looking for a few good duct cleaners. In a recent ad in the Times classifieds, "10 immediate openings" were advertised, with "$500 sign on bonus" offered for people with "no experience" necessary.
Local manager Thomas Rivera said the company only hands over that signing bonus after an employee has worked five days a week without missing a day for four months. While it's true no experience is needed, he said, the company provides training to its workers.
United Restoration isn't the only company that is considered questionable, Hebert said. Some of the nation's department stores regularly advertise bargain rates on air duct cleaning. Hebert said he has done inspections of one major chain's duct cleaning work — which he said is subcontracted out — and found it unsatisfactory.
"Their work did not meet NADCA standards", he said.
Ehrlich said one of the lingering issues the Cincinnati Better Business Bureau has with United Air Comfort is its use of a dust mite image in their ads, which she said is misleading. Blown up to hundreds of times its microscopic size, the dust mites crawl across the company's ads, looking like mean, hairless spiders. Next to the mite is a line that says duct cleaning "helps eliminate dust mites breeding in your vents". There is no evidence to support that claim, she said, or at least none she has been shown.
Tim Hebert flatly calls use of the dust mite a scare tactic.
"Dust mites don't normally grow in air ducts", he said. "Dust mites grow in areas that you frequent in your home — your bathroom, your couch, your bed. They are rarely going to grow in ducts, unless you personally are living in your air ducts".
But dust mites can pose a valid health threat. A study released in January by the National Academy of Science's Institute of Medicine, called "Clearing the Air, Asthma and Indoor Air Exposures", points to dust mites, as well as cat and dog dander, as a prime cause in asthma. The study was commissioned by the EPA's indoor air pollution division.
Dr. Thomas Platts-Mills, a professor of medicine at the University of Virginia who worked on the study, said it showed that indoor pollutants and allergens are more important contributing factors in asthma than outdoor pollutants. But whether that indicates a need for air duct cleaning is unclear, he said.
"We know there is stuff in there and we think it makes sense to remove it if someone has symptoms of asthma", he said. "But there are no good standards for the techniques in cleaning. There are some people who clearly just apply a little vacuum cleaner to it. And there are people that use a strong vacuum and remove a lot of stuff. The problem is, we don't know, did they remove 95 percent of what's in there, or only 5 percent?"
"I think it's an area where extraordinarily little science has been done", he said.
Like Hebert, he emphasized the fact that those who want to rid their houses of dust mites shouldn't bother with duct cleaning, since the creatures don't live there. But dog and cat dander, as well as fungi, do accumulate in ducts. Here's the tricky part.
"The problem with that is, maybe the ducts are cleaning the air", Platts-Mills said. "And maybe then, if you go in and clean it, you may disrupt some stuff".
Back at the Keagys' house, Pam's allergies seem like they are just a bit better. But she isn't sure what to attribute it to because she's doing every little thing she can to improve her situation. She is on some new treatments and it is the off-season for grass pollens, which she thinks cause most of her problems.
"If it had an effect it would have been one more step in eliminating molds and pollens in the house", she said.
But she doesn't have any regrets. She is grateful for even a bit of relief.
Bob Van Gelder said about 25 to 30 percent of his customers suffer from respiratory problems, like Pam Keagy.
"They are the ones who really respond", he said.
Despite the "too-good-to-be-true" companies proliferating the business, he is — not surprisingly — still a dedicated believer in duct cleaning. And he thinks anyone who sees the results of a good duct cleaning will agree with him.
"When you see the garbage that comes out", he said. "Oh, it comes out so dramatically. It's like emptying a vacuum cleaner".
"This industry is in its infancy", he added. "People are just waking up to this".