Do you need your ducts cleaned? This is an ongoing question many homeowners are presented with. We are often told that to have healthy clean air in our homes we should have our forced air furnace ducts cleaned to make sure we do not get dust into the air we breathe. There could also be deadly mould growing in them. At first thought, it makes sense, who would not want dust-free air, who would not want better health.
I would like to look a little deeper into this. As a renovator, I have seen the insides of ducts that are over a hundred years old. They are dust-coated but still 98% open. What happens in ducts over the years is that dust very slowly attaches to the duct surface. This accumulation could actually be a sign of something good, not bad. That is, dust that was once circulating in your home is now out of circulation and trapped just as your furnace filter is trapping dust although in much bigger volumes.
Generally, there is no need to remove the dust. You may want to keep that dust in the ducts because once you get a little dust trapped there it makes it easier to capture more dust on the now unsmooth surface. If it does manage to break free for some unusual reason, your furnace filter will trap it. It may have to pass through your living space once more, but the overall effect is that dust is being reduced in your home. When one reads about the horrors of dust in your ducts it is made to sound like the ducts are actually generating the dust and therefore need to be cleaned.
The US Environmental Protection Agency says: “Duct cleaning has never been shown to actually prevent health problems. Neither do studies conclusively demonstrate that particle (e.g., dust) levels in homes increase because of dirty air ducts. This is because much of the dirt in air ducts adheres to duct surfaces and does not necessarily enter the living space.”
You can find more about this unneeded service at the Washington Post.
Here is a typical example of fear and misinformation about duct cleaning.
There are sometimes unique or special problems that might require duct cleaning. Some examples would be:
· If there is mould. Be very skeptical unless it is rigorously tested for as lots of small particles look like mould but are not. This would also prompt you to ask how and why moisture is entering the system.
· Vermin like rodents or insects. Again this points to other problems like holes in your ducts and unsealed food sources.
· Debris from a renovation that can actually block airflow.
Also be aware that clothes dryer ducts are quite different from forced air ducts, and they do need cleaning regularly to prevent build-up that can block them or even cause fires.
I hope this information helps a little.