Expert Answer: Lifespan of Ductwork – Bell Brothers

Bill in Rancho Cordova, CA has been dealing with some HVAC troubles, like dust coming from his vents and uneven heating in his house. He suspects his ductwork is old and possibly to blame. Bill asks:

“I’ve been reading your blog for a while and I’ve started to realize that there’s a critical part of my HVAC system that I don’t think much about: the ducts. I know that I could stand to learn quite a bit more about this component, and maybe other Rancho Cordova homeowners could too.

Lately, I’ve noticed that there is more dust than usual coming out of my vents. And, over the past year or so, it has started to take longer for my HVAC system to cool down or heat up my master bedroom. My questions are whether or not this is connected to the ducts and, given that the house I live in is several decades old now, how long does ductwork last? I suspect that if not now, I will need to replace mine fairly soon.”

I don’t know if you’re into cars at all, but if you are, you’ll know that over time some things get better with age and become what we like to call a classic. Ducts, however, are not one of these things. They can, and do, wear out and start to have so many problems that the smart move is not to repair them, but to replace them. I’m not sure if Bill needs to replace his ductwork or just needs some maintenance, but from what he told me above, I’m fairly certain that his ducts do needs to be looked at by a professional. First, though, let’s address Bill’s big question: how long does ductwork last?

How Long Does Ductwork Last?

On average, ductwork lasts 10 to 15 years before it needs to be replaced. Simply put, if you have lived in your house that long and haven’t ever had the ductwork replaced, well then, it’s time to call in a ductwork installation pro.

It may not seem like it, but from a heating and cooling service professional’s point of view, ductwork is one of the most vital components of any HVAC system. It is the circulatory system of the HVAC system, akin to the veins that move blood throughout your body. Ducts are responsible for carrying the conditioned air from your furnace or air conditioner into the rooms in your house to keep you and your family comfortable year round. You need to make sure that they’re kept as healthy and clear as possible.

Signs It’s Time to Replace Your Ductwork

I’ve talked about the signs that it’s time to replace your ductwork in the past, and Bill here is actually dead on about two of them. Let’s go over the most common signs again here in brief:

• Your home is very dusty. Does it seem particularly stuffy or dusty in your home these days? Are your allergies acting up? Bill doesn’t say how, but he has noticed more dust. If you’re like Bill, it’s possible that your ducts have holes, gaps, or are improperly sealed. When this is the case, dust from outside the ductwork gets inside, travels through the ducts, and ends up in your home. Another possibility is that ducts carrying exhaust are leaking into your home—something that negatively impacts your health and the air quality in your home.
• You smell mildew. If you notice a funny smell coming from your HVAC ducts, there’s a good chance they’re moldy inside. Sometimes, when warm, moist air travels through cold ductwork, condensation forms. This typically happens if your ductwork isn’t insulated well or if the air moving through the ducts is particularly humid. Over time, condensation can encourage mold growth in the ducts, blowing unhealthy (and smelly) air into your home. Ducts can also leak condensation, which can cause a mold problem inside your ceiling. So, if you smell something funky, have your ducts inspected! A professional will have the right equipment needed to detect mold—even deep inside your ductwork.
• Your HVAC unit is noisy. Your HVAC system should run pretty quietly. If it seems exceptionally noisy to you, it may be a sign that your ducts are too small for the size of your HVAC unit or that the ducts are imbalanced. When this is the case, your system struggles to push air through too small of an opening, stressing your furnace and air conditioner and driving up your energy bill.
• Your home’s temperature is inconsistent. Another thing that Bill has noticed is that his master bedroom is feeling much warmer or cooler than the rest of his house. This could be a sign that he has leaky HVAC ducts that are losing air and failing to sufficiently heat or cool certain parts of the house. It’s also possible that inconsistent interior temperatures could be the result of unbalanced ductwork, so make sure you have a seasoned HVAC pro diagnose this problem correctly.

These are all signs that your ductwork needs some love—or that your home is ready for a full HVAC duct replacement, which Bill’s very well may be. Now, don’t try poking around yourself, though. If you have a situation similar to Bill’s, I highly recommend calling an experienced HVAC tech out to your home. They’ll be able to perform a thorough inspection of your ductwork using specialized tools to correctly diagnose any and all duct drama. Then, they’ll also help you to decide what the best course of action is. In some cases, you will need to replace all of your ductwork, but it’s also possible that all you’ll need is a few repairs or an insulation upgrade.

Ductwork does wear out, usually around the 15 to 20-year mark…

There you have it. Ductwork does wear out, usually around the 15 to 20-year mark, and it is actually very important that you get it replaced—unless you want to deal with dust, uneven heating, the smell of mildew, and a noisier than usual HVAC unit.

But if you don’t want to grapple with those things (and who does?) my advice is to call your friendly neighborhood HVAC repair service. Any service worth its salt will have specialized tools to do a full inspection of your ductwork and tell you beyond a doubt whether or not it needs to be replaced. So stop worrying about your duct dilemma, and take action today!

Contact the HVAC professionals at Bell Brothers to schedule a whole-house assessment for energy efficiency. We’ll offer recommendations and upgrades that are sure to increase your year-round comfort—and decrease your power bills.

Wondering how to finance a new HVAC system, windows, or plumbing? HERO is a unique financing option that helps California homeowners afford energy efficient upgrades to their home. Contact Bell Brothers, a HERO-approved contractor, to learn more. Our local HVAC, plumbing, and window specialists will walk you through the entire process, from applications to installation.

Image courtesy Zinkevych