What Constitutes an Old AC System?

Woman thinking with text: "what constitutes an old AC system?"

Hot Topics and Cool Conversations with Eric Pace

Aire Serv® of Fort Bend

Operating since 2009


With the summer heat upon us, AC units are kicking into overdrive to help keep us cool and comfortable. However, for many people, they could be a different kind of hot when they receive their latest utility bill. If your utility bill is higher than normal, don’t write it off as the “cost of summer,” as it may be a result of an old AC unit.

Eric Pace with Aire Serv of Fort Bend offers his expert insights on how to identify an exhausted unit, and when it might be time to replace it.

Aire Serv: What are the signs that your old AC unit needs to be replaced?

Eric Pace: If your utility bill starts going up or you are having to schedule a lot of repairs on your AC unit, you may want to consider replacing it. Typically, we tell customers that if the unit is eight to 10 years old, and their spending $500 or more on the equipment to get it back up and running, it’s time to change the system. Each repair you do to an old unit is money you are throwing away. Instead, you could invest in a new unit that is more efficient, has a warranty, and over the long run, costs you less money. Another telltale sign that you may need a new system is when the coils start to oxidize, change colors, show calcium build up, or begin to rot. We have seen units as young as five years old where the coils are rotted so bad, just touching them would make them fall off. Overall, the length of time an AC unit lasts depends on the climate, where you’re at, and what brand of unit.

Aire Serv: Are there any signs that are difficult to identify that you should be looking for?

Eric Pace: If a unit is installed correctly, given regular maintenance, is 10 or more years old, and requires small repairs ($200-250), you should consider how many times you’re having to schedule those small repairs. Once you add up the small repairs needed, it may equal to a much larger repair cost over time. If efficiency drops off or utilities go up, those are dead giveaways to consider getting a new system. If you’re utility bill goes up $75-100 from one month to the next, you need to evaluate what in your home uses the most electricity. If it’s air conditioning, instead of just saying, “Well that’s the cost of summer,” it may be because an old AC unit is in need of replacement.

Aire Serv: What dangers could be present with using an old AC system?

Eric Pace: The dangers in using an old AC system are leaking refrigerant getting into the air stream causing a health concern. Also, the older the AC system is, the more it needs to be cleaned to guard against mold or mildew, which also goes directly into the air stream. Mold and mildew in the air can cause respiratory issues for those inside the home. Outside the home, dangers include leaking oil onto the plants and grass, as well as sharp rusty areas that can cause injury.

Aire Serv: What are some of the benefits of replacing the AC system?

Eric Pace: When considering a repair versus replace, look at the whole picture. The first day the new system is running, you automatically increase your efficiency a minimum of 42 percent. Not only does efficiency increase, but also airflow increases in your house. With a new AC system, you also will have warranties. In fact, most equipment has a 10-year warranty on parts and compressors. For 10 years, you will not have to worry about paying for parts. With an old system, it will be 42 percent less efficient and will continue to diminish in efficiency and capacity. New AC systems, featuring modern technology, will be more efficient, have adequate capacities at levels they need to be, and a warranty that lasts for 10 years.

Aire Serv: Do you have any advice to homeowners looking to make a replacement purchase?

Eric Pace: It is vital to have a maintenance agreement in place for the life expectancy of the unit. Each year you don’t do maintenance, you put undue wear and tear on the unit. It’s crucial to keep a maintenance contract in place to keep the unit running correctly. You can equate it to an engine in a vehicle. Should you change your oil? Yes, you should. Can you keep adding oil to the motor without changing the oil? Yes, but at some point, that motor is going to give up, the bearings are going to wash out, and you’re going to have a major repair that will cost thousands of dollars. An AC system is the same way – it requires maintenance. Having a maintenance plan where a professional is cleaning your unit and putting their hands on it twice a year is recommended to protect your AC system and prevent unnecessary repair expenses.

If you think your AC unit may need to be replaced, contact your local Aire Serv professional.