CouponsHere’s what you need to know about AC compressors
Most homeowners tend to think of their “air conditioner” as a single unit. However, your air conditioner is actually more of a collection of components that work together as a single system: from the wall-mounted thermostat that sends instructions to the unit and the blower in your attic to the outdoor condensing unit, refrigerant line, and the condenser. In this article, we’ll review one of the most critical of these components, AC compressors, including taking a look at how they work, what can go wrong with them, and when it makes sense to replace the compressor or the entire air conditioner.
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What are AC compressors?
All air conditioners (and heat pumps) operate on the same basic principle: they use refrigerant to transport heat energy from inside your home to the outside, repeating this cycle again and again until the air temperature in your home cools to what your thermostat is set to.
AC refrigerant is uniquely formulated for this purpose: when heated, it transforms from its liquid form into a gas. Upon releasing this heat energy, it goes back to being a cold liquid. Your air conditioner’s blower unit pushes air over this chilled refrigerant, which then absorbs more heat from inside your home.
To move in its closed loop, the refrigerant needs to be properly pressurized. That’s where the AC compressor comes into the picture. Just like a garage compressor you use to fill bike and car tires, AC compressors use energy (electricity) to generate the pressure needed to allow for refrigerant to move and change states. You might think of the compressor as a pump that keeps the entire cooling cycle moving. No compressor, no cooling.
What can go wrong?
Well, just like that compressor in your garage (or really any part of your air conditioner), the AC compressor can start to show signs of wearing down. While it’s built to handle some degree of heat—after all, it’s housed in the outdoor unit where heat energy is being actively dispersed into outdoor air—many premature compressor deaths are caused by overheating.
The compressor is the heart of your air conditioning system, responsible for circulating refrigerant that absorbs and expels heat from your home. It is designed to operate within a certain temperature range, and while it is equipped to manage the heat, excessive temperatures caused by external conditions or internal malfunctions can lead to significant damage. For instance, if the cooling fins around the compressor are clogged with debris, this can impede the unit’s ability to expel heat, causing the compressor to overheat.
Additionally, improper refrigerant levels—either too high or too low—can also cause the compressor to overheat. Low refrigerant levels force the compressor to work harder to pump sufficient refrigerant through the system, leading to increased strain and heat. Conversely, too much refrigerant can lead to increased pressure within the system, also generating excess heat.
Moreover, a lack of regular maintenance can leave other components of the air conditioning system, such as condenser coils or air filters, functioning poorly, which further exacerbates the problem. Dirty coils or blocked air filters restrict airflow, reducing the system’s efficiency and increasing the temperature within the compressor.
Furthermore, electrical issues can also lead to compressor overheating. Faulty capacitors or damaged relays can cause erratic compressor behavior which often leads to overheating. Electrical faults may lead to sporadic and uncontrolled on-off cycles that do not allow the compressor adequate time to cool down.
It’s crucial to monitor the health of your AC compressor regularly and to undertake preventative maintenance to ensure it operates efficiently. Regular checks by a professional can help identify and rectify issues like dirty coils, incorrect refrigerant levels, and electrical faults before they lead to compressor failure. This not only prolongs the life of the compressor but also maintains the overall efficiency and effectiveness of your air conditioning system. Regular maintenance ensures that the system can continue to provide effective cooling without the risk of premature breakdown due to overheating.
Age
Unfortunately, the compressor is typically the first major component to go in an air conditioner as it ages. Most compressors last about 10-15 years, which roughly translates to the overall lifespan of most air conditioners. However, several factors such as environmental conditions, usage patterns, and installation quality can influence this timeline. With the right preventative maintenance and some attention to the issues listed below, homeowners can typically extend the lifespan of their AC compressors to 15-20 years. Regular inspections, timely filter changes, and cleaning of the condenser coils are essential steps that can help prevent premature wear. Addressing minor issues promptly, such as refrigerant leaks or unusual noises, can reduce the strain on the compressor and contribute to a longer operational life. While these proactive measures are effective, it’s important to acknowledge that compressors, like all mechanical components, have a finite lifespan. Eventually, even with the best care, the compressor will succumb to the natural wear and tear of continuous use, and replacing it may become inevitable.
Overheating
Overheating occurs when the heat energy released in the condenser (that’s the outdoor unit) cannot ventilate properly into the surrounding outdoor air. Most often, this happens when nearby bushes, shrubs, trees, or decorations are positioned too close to the AC unit, restricting airflow around the condenser. As a result, hot air becomes trapped around the unit, leading to a buildup of heat that is unable to disperse effectively. This trapped heat gradually increases the temperature of the AC compressor, putting additional strain on the component until it eventually overheats and fails.
When the unit is obstructed, even a slight reduction in airflow can significantly impact its efficiency and performance. Not only does this result in overheating, but it also forces the AC system to work harder, potentially leading to higher energy consumption and increased wear on other critical components. Routine maintenance, such as trimming back vegetation and ensuring that the area around the unit remains clear, is essential to prevent these issues. Additionally, regular inspections can help identify and remove any debris or objects that may inadvertently block the necessary airflow, ultimately protecting your compressor from premature failure due to overheating.
Refrigerant Leaks
The refrigerant in your air conditioner exists in a closed-loop system that is sealed off from the environment. In theory, you should never need to add more refrigerant because it is meant to circulate indefinitely without loss. However, over time, refrigerant leaks can occur due to wear, damage, or faulty connections, leading to a gradual decrease in refrigerant levels. When the system loses refrigerant, it puts additional stress on the compressor, forcing it to work harder to pump the remaining refrigerant in order to generate the cooling needed inside your home.
This extra effort not only reduces the overall efficiency of your AC unit but can also lead to long-term damage if not addressed promptly. Low refrigerant issues and AC compressor issues are often interlinked, meaning that a small leak can evolve into a major repair issue if left unchecked. That is why it’s critical to call in a professional if you suspect your AC unit is losing refrigerant. An expert can accurately diagnose the leak, repair it, and recharge the system, ensuring that your air conditioner continues to operate at optimal performance while avoiding further damage.
How much do AC compressors cost to replace?
The AC compressor is one of the most specialized and intricate parts of the air conditioner. As such, it’s a relatively expensive component to replace. Typically, the decision to replace a compressor comes down to the age of the system:
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- If the air conditioner is less than 10 years old, it and its compressor may be covered by the manufacturer’s warranty, provided the homeowner has continued to meet the eligibility requirements, such as scheduling annual maintenance.
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- If the air conditioner is more than 10 years old, most HVAC technicians may advise you just replace the entire system. In a rough analogy, putting a new compressor into an aging air conditioner is like replacing the engine in an old car—even with a new compressor, the other components are still aging.
What should I do if my air conditioner stops working?
The first thing you need to do is bring in a professional to take a closer look. There’s a number of things that can go wrong with an air conditioner, and sometimes issues aren’t always as cut-and-dry as they initially appear. A trained technician will be able to diagnose any underlying problems that may not be immediately obvious, saving you time and money in the long run. Many problems can mimic the symptoms of a failing compressor, but may be resolved through simpler repairs or adjustments.
If you’ve already had a technician out from another company to take a look at the system, and they’ve recommended a compressor replacement, call us to have one of our NATE-certified technicians give you a second opinion. Our experts bring years of experience and an in-depth understanding of HVAC systems to each job, ensuring that the diagnosis is both accurate and thorough. They can often identify alternative issues—such as refrigerant leaks, electrical problems, or clogged filters—that might be mistaken for a failing compressor.
In addition, our comprehensive evaluation includes a detailed assessment of your system’s overall health. We examine the compressor, wiring, refrigerant levels, and airflow to ensure that every component is functioning properly. This holistic approach means that we rarely recommend a compressor replacement unless it is absolutely necessary. Taking this extra step can help you avoid unnecessary expenses and extend the lifespan of your air conditioner. Trusting a second opinion from our skilled team can give you peace of mind, knowing that you’re making a well-informed decision about your HVAC system.