Last Modified On 8/27/24
One of the most surprising facts about central air conditioners is that they actually need more power than residential electrical systems provide. When your home starts a cooling cycle, it relies on its capacitor to ramp its motors up. Without a functioning capacitor, an air conditioner may run indefinitely, but it will never have the ability to bring indoor temperatures down. However, even as they rank among the most important components in AC systems, AC capacitors are both overworked and little understood. Following is everything you need to know about AC capacitors, including what you should do when yours stops functioning. If you are experiencing this problem and live in the Hampton Roads area you should let us know. Be sure to also get more home service tips on HVAC, electricity, and plumbing.
Understanding AC Capacitors: Core Functions and Part Location
An AC capacitor is located in an air conditioner’s outside condensing unit. Although an air conditioner is connected to and powered by a home’s electrical wiring system, its energy demands exceed the output of this system every time a cooling cycle is started. At the beginning of a cooling cycle, the capacitor sends out several quick jolts of electricity to the air conditioner’s motors. These jolts rev the motors up to start the cooling cycle. Once the cooling cycle is engaged, the capacitor ramps its energy output down and provides a steady stream of power to support the cooling cycle through its end.
When the ideal temperature has been reached in the interior of your home, your thermostat sends a signal for the AC to turn off. As soon as the cooling cycle ends, the capacitor starts storing up energy for the next round. In essence, as long as your air conditioner is on, your AC capacitor is never at rest. If it isn’t actively working, it’s actively preparing for the next cooling cycle. As such, it is easily one of the hardest working components in your air conditioner.
When you buy a new air conditioner, you’ll be given information on the model’s expected lifespan. For most ACs, this is about 15 to 20 years. However, even though your air conditioner might be rated to last this long, this doesn’t mean that all of its components will. In most households, AC capacitors need to be replaced approximately twice throughout an air conditioner’s lifespan.
Many Air Conditioners Have Two Capacitors
A single, dual-function capacitor can both rev up your air conditioner’s motors for the cooling cycle and then keep them running until the cooling cycle reaches its end. However, some air conditioners have two separate capacitors for each task. They have a start capacitor that sends out a short series of quick jolts, and they also have a run capacitor that provides a continuous stream of energy. If your air conditioner has two capacitors, you may find that only one capacitor fails and the other continues working. In this instance, an HVAC technician might recommend having both capacitors replaced with a single, dual-function unit. Dual-function capacitors cost more upfront, but they make future capacitor replacements both cheaper and easier.
How To Recognize a Failing AC Capacitor
One of the most common signs of a failing AC capacitor is an overly warm home. Without this component, the cooling cycle won’t start and indoor temperatures won’t go down. Other signs of capacitor problems include:
- Loud humming sounds coming from the AC condenser
- Having your air conditioning shut off without warning
- Burnt odors or smoke coming from the outdoor condenser
Capacitor problems are common after power outages. Without surge protection, the sudden restoration of power can burn these components out.
Caution: Replacing An AC Capacitor Is Difficult
Here is why you should think twice before attempting this process. Replacing an AC capacitor is not a simple swap like changing a battery. Capacitors are integrated into your air conditioning system with specific wiring and require precise handling to avoid severe risks, including electrocution. Unlike other DIY projects, capacitor replacement demands specialized tools and expert knowledge to ensure safety and correct installation.
Attempting this task on your own not only endangers your safety but also risks voiding your AC’s warranty. Improper handling can lead to invalidation of the warranty, forcing you to cover all future repairs out-of-pocket, even those due to manufacturing defects. Furthermore, selecting the correct capacitor involves understanding specific requirements that vary by AC model and previous replacements, a task best left to professionals to prevent recurring issues.
Remember Annual HVAC Maintenance Is Important
Proper maintenance goes beyond occasional fixes; it involves understanding the early signs that your system might be faltering. Schedule regular inspections with certified technicians to catch issues like capacitor wear before they turn into costly problems. This not only ensures your air conditioner’s efficiency but also extends its lifespan, saving you money and discomfort in the long run. If you are feeling lost and can’t locate your capacitor or would like to know if it needs to be replaced, please give us a call, will be there to help.