How Long Does Ductwork Last?


Ductwork is out-of-sight, out-of-mind, so it is very easy to forget that the ducts, like everything else in the home, require maintenance.

Your ductwork is vital to the operation of central heating and air conditioning since those systems use it to distribute air throughout your home. This means that the air system has an effect on your energy bill as well as your air quality.

Old ductwork can also shorten the life of your HVAC system by forcing it to work harder than it should. Maintaining and, when necessary, replacing old ductwork is one of the most important yet overlooked things that you can do to lower energy bills and improve air quality in your home.

How Long Does Ductwork Typically Last?

Most ductwork will last for 10-15 years before you need to consider repairing or replacing it, even though it usually has a maximum lifespan of 20-25 years. It often begins to deteriorate much sooner than that.

Deterioration happens over time because ductwork moves. It expands in winter when it is used for heating and then contracts in summer when it is used for cooling. In addition to the expansion and contraction caused by the change in the temperature, vibrations from the fans pushing air through the house can cause damage.

While the movement of the air ducts is largely unnoticeable, it does actually have an effect on the duct system. Over time seams will pull apart, creating leaks. This makes the HVAC system far less efficient, as the cool or warm air that it is trying to direct into your home leaks into your attic or crawlspace.

The metal in the system can also rust. This happens mainly during the summer, when the cool air running through the ducts causes condensation to collect on the metal. That rust can corrode the metal until it has created holes in the work, further reducing the efficiency of the HVAC system.

Leaks can also affect air quality. If the system runs through the attic, they can allow dust into your system. If they run through the crawlspace, they can pull in the dirt, mold spores, and other particles into the ductwork. Since these contaminants will essentially be bypassing your air filter, they can significantly degrade the air quality in your home.

How Can You Tell If Your Ductwork Needs Replacing?

Since the ductwork is largely out of sight, it can be difficult to determine when it needs replacing. Here are the three easiest, most reliable ways to determine if yours should be replaced.


Ductwork has a maximum lifespan of 20-25 years, and starts to deteriorate around year 15. If your ductwork is more than 15 years old, you may need to have the ductwork inspected to see if it is time to replace it. If it is older than 25 years, you almost certainly need to replace the ductwork.

It is possible that previous owners replaced the ductwork, and that the work is younger than the house. However, it is not likely. Most people never think to check, so it is very likely that the previous owners did not replace it, and that the ductwork is the original ductwork that was built with the house.


While there are a lot of different reasons your utility bills are increasing, bad ductwork may be the culprit, If you have considered and resolved the other issues in your home that could be contributing to the added utility costs and nothing seems to be helping, it is time to consider your ductwork. In fact, most people are so aware of everything else they need to do to conserve energy that it has become very likely that bad work is the cause of most high utility bills.

Our Home Comfort Heroes can perform an air leakage test also known as a blower door test to determine if your ductwork has developed leaks. If the leaks are small, you can easily patch them. Even duct tape will fix it (it is called duct tape for a reason, after all). If they are large, you will need to replace your ductwork.


Holes in the ductwork allow pollen, dust, and other contaminants into your air supply in quantities that would never get past your air filter. It can make allergy and asthma symptoms worse, cause irritation of the eyes, and contribute to other health problems.

Leaky ductwork can even help facilitate the spread of mold throughout your home, which is not good for your health, create unpleasant odors in the house, and damage your HVAC system.

Take the First Step & Give Us a Call Today

The only way to be absolutely certain that your ductwork does not need to be replaced is to give Service Legends a call for a free inspection. We can advise if any repairs are necessary and can do the work if we find the ductwork needs to be replaced. 

Old, leaky ductwork can cause serious problems in your home, and if you suspect that it needs replacing you really should not wait before having it checked out. If you suspect your HVAC system is old and needs replacing, contact Service Legends today to schedule a free consultation.

515-657-6634Request Appointment Online