rusty a/c unit connecticutWe’re often asked how long an air conditioner’s lifespan is, though the answer isn’t cut and dry. According to the Energy Department, the average AC unit will last roughly 10-15 years. However, the actual longevity of your AC unit will depend on several factors only you can determine.

What factors play a role in your AC’s lifespan?

For a look at the possible lifespan of your AC, consider your personal habits.


Wear and tear will play a role in how long your AC unit lasts. While the average homeowner would need to replace their unit every 10-15 years, someone who rarely uses their AC might be able to wait for 20 or more years before replacing their AC.

Tip: To improve your AC lifespan?, reduce your usage. Remember to turn it off when you’re away, or resist the temptation to turn it on during moderately warm days.


Humidity will cause your AC unit to work on overdrive even if it’s not cooling your home. The humidity will trick your AC unit into keeping the fan on because the coils inside will do their part to absorb the moisture from the air. This extra strain on your coils and fan can decrease your AC’s lifespan.

Tip: You can take steps to minimize humidity in your home by purchasing a dehumidifier, or growing plants that reduce moisture in the air like Boston Ferns, Palms, or Cacti.


The cooler you run your AC, the more strain you are putting on it, especially if you forget to give it a break. Not only does frigid air force your unit to work harder, but it also increases your bills. According to the Department of Energy, 78 degrees Fahrenheit is the most efficient temperature to run your AC when you’re home, and you should increase it to 85 degrees or off while you’re away. Adversely, adjusting your thermostat to just 72 degrees can increase your bills by roughly 47 percent.

Tip: By nudging the temperature up just a couple of degrees, you will be putting less strain on your AC, and effectively increase its lifespan while decreasing your bills.


Debris on coils, ductwork, or other components of an AC can cause it to malfunction due to a lack of airflow. Specifically, with an interruption of proper airflow, your AC can freeze up. And, if this happens, and isn’t caught early enough, the frozen unit can cause water damage your AC, reducing its lifespan.

Tip: Every two-three months, give your AC a routine checkup. Change the air filters, wipe debris from the coils, and check your ductwork to make sure nothing has collapsed or loosened. A clean unit makes for a longer-lasting system.

Preventative Maintenance

The better you take care of your AC unit, the longer it will last. Scheduling preventative maintenance with your local HVAC company can help extend your AC’s lifespan, and ensure it’s operating at maximum efficiency, which can also help reduce your monthly bills.

Tip: Industry experts agree that a bi-annual checkup — performed by professionals — for your AC unit is best practice to maintaining a long-lasting system.

What are the aging signs of an old AC unit?

Higher Energy Bills

The older your AC unit gets, the less efficient it can become. In fact, there is a measurement to help you gauge your lost efficiency called The SEER (seasonal energy efficiency ratio). Each year that passes, your AC unit can lose up to 9 percent efficiency. And,  every decrease in percentage points means an increase in your energy bills.

Strange Smells

Without proper maintenance to your AC unit over the years, it’s possible for mold and mildew to grow in the ductwork. This is harmful to the air you breathe, and also indicates that your AC is weathering damage. A burnt scent indicates issues with your wire insulation — another indication that your AC unit is aging. If you can smell your AC, then it isn’t operating well; start by giving it a good clean. If the smells don’t go away, consult an expert to see if your AC needs an update or an upgrade.

Increased Noise

When your AC unit makes noises like a squeal, grind, or grating noise, it doesn’t take a rocket scientist to realize something is not right. These noises may indicate a simple fix, but can often require more technical maintenance. If your AC unit is making strange noises that you’d can’t quickly identify, it’s time to call in an expert.


Leaks from your air conditioner come from two primary sources: refrigerant leaks and leaks from the condensate line. Both instances are caused by faulty components in your AC unit where parts are either broken or blocked, which can be a sign of aging. It can also be a sign of danger. Refrigerant leaks can be harmful to you and your family due to the toxicity of freon in the refrigerant. And, in both scenarios, without proper detection of a leak, mold can grow in the leakage, which is harmful to breathe. Ongoing maintenance can help with prevention and early detection of leaks. Additionally, if you spot a leak, call an expert to help you rectify the situation immediately.

How to decide when to replace your AC unit?

After diagnosing an issue with your AC unit, you may take steps to repair it yourself, or you might seek advice from an expert. Whichever route you choose, make sure to conduct a full inspection of the unit.

A comprehensive AC inspection includes:

After a thorough inspection, you and your technician should have a full picture of the severity of your AC issues. This is how you can decide if it’s more cost-effective to repair or replace your system.

Luckily, technology has evolved in a way that makes our HVAC equipment last longer than ever, and perform more efficiently than equipment of the past. In fact, the most efficient, modern air conditioners use 20 to 40 percent less energy than models made in the early 2000s. So, when it comes time to replace your outdated technology, it can actually be an opportunity for cost-savings for you as a homeowner.

Learn more about energy efficient air conditioning equipment in Fairfield and New Haven Counties, CT.