I didn’t want to have my home’s air ducts cleaned but my wife saw a coupon in one of our local papers that advertised a “$39.95″ special that included a cleaning of 10 vents and 1 intake trunk of a forced air heating or AC system. A while ago I asked the question, “Is It Really Necessary To Have Your Air Ducts Cleaned?” so I was skeptical, but our house is over 50 years old and the vents had never been properly vacuumed out to my knowledge.

Here you see the dust that’s been built up on a piece of aluminum that was cut out of my ducts. This is from the intake side of my 50 year old duct system.

Any forced air heating system works by pulling in air through the intake vents and then heated or cooled before being blown out through the floor or wall vents. In theory all that air being sucked in is filled with dust and dirt and all sorts of awful things in your air. Sure, a lot of it should get caught in your air filter, but a lot of natually will settle in your ducts before even getting to your filter.

My wife took my son out for a grocery run and I was left to deal with the casually dressed but well-mannered vent cleaners who arrived in an unmarked white van. They had no uniforms or even business cards, but they introduced themselves as Bob and Ken.

I showed them the coupon and they quickly got to work. They took a quick survey of the house and the number of vents I had. They then went down to the basement where my furnace was and gave that a quick once over. Then they got to work.

The first step was running a 12 inch diameter vacuum hose from the white van, through my side door, down my basement stairs and right to my furnace. They then brought an extension cord to me and asked if I had a place to plug it in.

Then Bob and Ken went down to my furnace, removed my air filter, picked out a spot along the main intake trunk of my vents and used a saw to cut a six inch hole in it. They pulled out the circular piece of aluminum that they’d cut off my ducts and I have to admit it was covered in about a half inch of dust and filth. Then they put the hose up to hole and drove some screws into a ring around the vacuum hose, essentially attaching the vacuum hose right into my intake vent.

They cut a hole in the air duct and attach this vacuum hose with screws.

Bob turned on the vacuum in their van and then started up an air compressor as well. The air compressor had a long hose which they brought from the van and into my home from the side door. Ken then proceed to each vent, sticking the rubber hose into the vent and releasing a little valve, which shot the compressed air into the vent. They were essentially blowing loose all sort of dust in my vents and because the vacuum was hooked up to the main trunk, all the junk was being sucked down to the vacuum.

Clever, I guess. It made a lot of noise and it did seem to loosen a lot of dust. Some was blown back into the house, which made for little grey clouds around the vent as they worked. After the first one they put little paper masks on. I just stood back.

After all the vents were cleaned the two guys proceeded down to the furnace again and drilled a small hole on near where the vacuum hole was attached. Now they ran the air hose into the hole and ran the hose around, making sure it hide the sides of the ducts while blowing air, essentially blowing loose more dust and dirt and causing it to be sucked up by the vacuum. At one point Bob loosened the vacuum hose and brought it down, showing me the amount of dust that was flying around the aluminum air ducts and being sucked away.

Before and after shots of the “blowing” side of my air vents. No, I didn’t see any difference, either.

I was impressed, but I had nothing to compare it to. I mean, was all that dust flying around in my house before this, or had it been resting safely in my vents for years without being disturbed? I also had to remember: this was on the intake side of the system, before the air went through a filter. Of course it was going to be dirty.

It was at this point that turned everything off and said, “Okay, now we work up an estimate.”

I still had two “trunks” of my air duct system not yet cleaned and, according to Bob and Ken, I should also have all my extending vents that blow out air cleaned. They would need to drill a hole (and later plug it up) about every 12 inches apart, they would spray in various fungicide and other magic chemicals to kill electrostatic discharge and cure my vents of whatever ails them. They figured the whole thing out to be around $600.

We had moved from $39.95 to $600 in less than 45 minutes.

I laughed, said no, and told them I’d go write them a check for $39.95 while they were cleaning up. They countered with a lower offer and we haggled back and forth. In the end I got them to clean the rest of intake trunks, one main blowing vent and clean out the furnace for about $250. It was still, in my opinion, too expensive, but I wanted to make my wife happy and there clearly was a fair amount of dust in these vents.

The verdict: In the end my vents were much cleaner, or at least less dusty, than they were before these two guys in their unmarked white van appeared. But I still think it was mostly a waste of money and here’s why:

All the impressive displays of dust came from the intake side of my forced air system. That’s the part of your furnace or central AC that pulls in air before it goes through an air filter, so of course that’s going to be dirty. I was able shove my camera into a smaller hole that they’d made in one of the “blowing” sides of the furnace and after 50 years it still looked relatively clean. Sure, after vacuuming that probably got out a few loose particles, but generally I found that side to be no cleaner than it was before Bob and Ken arrived.

Is my interior air cleaner? My wife swears she can breathe better, but I’m not completely convinced. Again, all those photos of clean and dirty ducts you see in the ads are clearly from the intake side of your forced air system, not of the side blowing out the air you actually breathe. The intake side will always be dirty because there is no filter. In fact, if the inside of your intake ducts are dirty I would consider that a good thing because it means your air system is pulling dirt and dust out of the rooms of your home.

Unless you’ve run your central AC or forced air heat for long periods of time without any sort of air filter at all (hey, it happens) then I would say that getting your air ducts cleaned is really not worth it. Save yourself the couple hundred bucks (or $39.95) for an air duct cleaning and use that money to replace your home air filter every 3 to 6 months.

Bob and Ken, of course. suggested I have my vents re-cleaned every two years, just to be safe, but I figured my home waited 50 years the first time so maybe I’d wait at least 25 years to get it done again.

Unless, of course, my wife thinks otherwise. Next time, though, I’ll let her deal with the Bob and Ken on her own.