Indoor Air Quality: Is Air Duct Cleaning Worth It?
Should You Get Your Air Ducts Cleaned?
In our last article, we explained that if you're concerned about the indoor air quality in your home, you may asking about duct cleaning. Is it worthwhile? You can search on-line and find conflicting information about whether or not you should have a duct cleaning company come in and clean out all the ducts in your heating and air conditioning system. If you do, you may have experienced the ugly, nasty images they show you to demonstrate what you might have going on in your air ducts. You're thoroughly horrified and you may be ready to hand over the cash, regardless of the amount.
But hold on a minute! Before you fork over the cash, make sure the company you want to hire is going to ask all the right questions. You see if you have dirty air ducts, you should be asking the question, "why are they dirty?" What are the causes?
Don't Just Treat The Symptom.
Duct cleaning can be very beneficial and be a good investment at some point. We encourage homeowners to be asking the questions and looking to solve the problems it reveals, instead of treating as regular maintenance. Don't just treat the symptom and leaving the cause there.
Dirty ducts aren't like dirty windows or a dirty carpets. If your ducts have a serious problem of being too dirty, you need to figure out why and then stop the dirt from getting in the ducts if you can.
One reason your ducts may be getting dirty is that your return vents, which pull air from the house back to the furnace to then send it back out heated or cooled to the rest of the house.
If your return ducts are located in your floor, they can be a magnet for drawing dirt into your system. Short of retrofitting the duct system to get the returns out of the floor, you should be using a filter inside the grille to keep your ducts cleaner.
Another major reason is duct leakage, especially on the return side of the duct system. Remember, the return ducts are under negative pressure('sucking' in Plain English) , so any leaks in them will pull air into the ducts. If that leak is in a dirty crawl space or attic, it's likely to be pulling in a lot of dirt, too.
A major culprit is when the installers used sheet metal to span wood floor joists or wall cavities (panned joist return) for your return ducts. With this set up, you may find a big floor grille, or they may have used a wall stack to get the vent into the wall.
Either way, panned returns are usually very leaky because the many joints and seams are often poorly sealed. Even if they were sealed initially, expansion and contraction at the wood/metal junctions can cause the seal to break down over time.
Duct Cleaning Isn't A Bad Thing.
Without treating the causes, though, it's a short-term relief of symptoms at best and perhaps a nightmare for someone with allergies if they stir up and release into the house all that nasty stuff that's inside the ducts. Duct cleaning should never be done without complete duct system analysis to find out where the dirt is coming from followed by the necessary repairs to stop the dirt from getting in.
Of course, you may consider a more comprehensive approach to fix the problems or causes. Any duct system repairs should take into consideration the air flow in the duct system. If you do, you have the potential to get ducts that stay clean as well as a more energy efficient and comfortable home.
That's why seeking the advice of a licensed HVAC Contractor, who understands the total system should be able to give you the best advice.