A lot of people want to suck my duct

I often work from a home office. For the most part it’s quiet and allows me to work uninterrupted, but there is one thing guaranteed to break my concentration: telemarketers. On a typical day I get between 1-3 calls from someone trying to sell me something. Some of these are rather benign — charities, blood drives, and the like, and I can hardly fault them for disturbing my day for a worthy cause. Some are service providers I have a business relationship with (phone, cable, etc.) doing customer satisfaction surveys, which I only object to when they turn out to be merely a pretext for an upsell pitch. But the majority are the type of telemarketers most of us dread, aggressively pushing products I don’t need. Of these, two stand out as particularly persistent.

The first are the computer optimization services, promising to make my Windows PC faster and more efficient by tuning the machine and removing viruses and malware. How did they know I had a Windows PC? Many suggest they’re associated with Microsoft itself — or almost do so, as you can pick up the weasel phrasing when you slow them down a bit. Of course, having always had a Mac, I know immediately that this is just a cold reading technique, no different than a psychic suggesting I’ll get news from a relative whose name starts with “J”, knowing most of us have a Johnny, a Jimmy, a James, a Jerry, a Justin somewhere in our family. Though even if I didn’t recognize it as such, there’s still no way I’d let a stranger touch a machine with so much personal data on it.

The second class of persistent telemarketer seems, at first, much more innocuous — air duct cleaning services. Whether I need my ducts cleaned right now or not, I can’t fault them for asking, and if I only got an occasional call I’d probably think nothing of it. But I get several of these a week, enough that I quickly started realizing something must be fishy.

After all, no other class of periodic home service calls with such relentlessness — I almost never hear from eaves cleaners, lawn mowers, or rug shampooers, for example. And even if my ducts were dirty, don’t I have a filter on my furnace that should stop any (or at least the vast majority of) dust from making it into my house? And if it didn’t, wouldn’t the inside of my registers be caked with dust? Where’s my screwdriver?

As it turns out, my instincts seem to be correct here, at least according to the US Environmental Protection Agency. In their brochure, “Should You Have the Air Ducts in Your Home Cleaned?” they make two key observations.

  • Studies fail to show that home dust levels increase because of dirty air ducts, as most of the particles simply cling to the duct walls. Most household dust is caused by cooking, cleaning, smoking, or bringing it in from the outside.
  • Further, there’s no evidence duct cleaning prevents any health problems.

While the EPA doesn’t call duct cleaning a scam outright, they’re pretty clear that there’s usually no benefit, and they limit the number of scenarios in which it’s appropriate, i.e.:

  • if there’s visible mold in your ducts;
  • if there’s a vermin infestation in your ducts; or
  • if you can see excessive amounts of dust actually being released into your home from your registers. Even here they note that the mere presence of dust on the registers is normal, easily cleaned by the homeowner, and does not indicate a problem.

They also warn against scam-like behaviour on the part of the duct cleaner, e.g. those “who make sweeping claims about the health benefits of duct cleaning”, stating that “such claims are unsubstantiated.” Additionally, they cite risks beyond your wallet — both from incompetence (poorly performed duct cleaning can release more dust into your home than none at all) and from the use of chemical biocides, which kill bacteria and mold, but are often inappropriate for use inside air ducts.

The EPA is a government agency, so it’s no surprise they’ve chosen their words carefully. I’m not under such official restrictions, so am in my unofficial capacity calling bullshit. Caveat emptor folks.


Photo courtesy of mikecogh via Flickr under Creative Commons.

12 Responses to “A lot of people want to suck my duct”

  1. Two of my children are asthmatic; the older one quite severe. When they were young, we lived in a house with a forced air furnace. Every fall we cleaned the ducts as well as we could using the vacuum cleaner hose. We then put filters on the vent louvres as well as replacing the filers on the furnace itself.

    Filters are not expensive and are easy to replace. You can also get a very good approximation of the dust in your system by checking the filters. It’s been over 20 years since we lived there, but I don’t recall the filters ever being very dusty.

  2. Scott Gavura says:

    We’ve had our forced air ducts cleaned once, after buying our house and following some minor renovations that left loads of dust everywhere.

    Regarding the biocide spray, this was an aggressively promoted upsell once they were in my house.

    I told the provider that if there was in fact mold growing in the ducts that passing a cloud of gas over it for a few seconds was unlikely to kill it. When I asked for some information on just what this product was, he could only tell me it was “all natural” and 99.9% effective. Sigh.

    • Dianne Sousa says:

      I would think you would still need to physically clean the ducts out, even if the biocide was effective at killing the mold, no?

      I know that for hard surfaces like ducts and painted walls, you should simply scrub up the mold with soap and water. There’s no need for disinfectant of any kind. Further, mold needs moisture to grow, so if it’s in your ducts you need to fix the moisture issue or else the mold will just grow back.

  3. Shawn Brooks says:

    The ones that call me always seem to be lurking about “my neighbourhood”.
    But they aren’t very good at answering, “Oh, where are you, what street is your team on?”

  4. Jeff says:

    I know it’s slightly off-topic, but you might find it useful to sign up for a phone service that lets you block numbers. I use (and quite like) Ooma, which has a “community blacklist” feature that prevents vast swaths of telemarketing evil from reaching you.

  5. Ken says:

    Well I get a call at least once a week from the same guys asking me if I want my ducts cleaned.
    I keep telling them that I live in an apt building and we have no ducts so please take me off the list. Yet the still persist.
    I have taken it a step further and ask to speak to a manager, and the line goes dead.

  6. al kimeea says:

    we get called fairly often for the ducts – whyaducks? – and once in a while for the PC cleansing – wifey always says something like ‘my IT professional husband is right here. Let’s ask him’ they always hang up

  7. jrkrideau says:

    And from a Canadian source: http://www.cmhc-schl.gc.ca/en/co/maho/gemare/gemare_011.cfm

    They are not terribly positive on duct cleaning although I like the one about lunch bags in the ductwork. :)

  8. Silverblaze says:

    An elderly lady friend of mine, who does not own a computer, responded to one of those calls about cleaning up her Windows by saying. “Oh I already have someone that comes to clean my windows!!” :-D

  9. Luke says:

    I’ve been saying BS to this duct cleaning service for years. If there’s dust in your ducts it’s either already blown out or not going to. And it’s filtered for crying out loud. This business uses the cliche health scam method of scaring you about things you ‘can’t see’.

  10. Jason says:

    We had ours done once after the house was built because the builder left drywall dust everywhere. I set out specifically to *not* use one of the several cleaners who cold-called us.


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  • Erik Davis

    Erik is a technology professional based in Toronto, focused on the intersection of the internet and the traditional media and telecommunications sectors. A reluctant blogger, he was inspired by the great work Skeptic North has done to combat misinformation and shoddy science reporting in the Canadian media, and in the public at large. Erik has a particular interest in critical reasoning, and in understanding why there’s so little of it in the public discourse. You can follow Erik's occasional 140 character musings @erikjdavis