AC capacitors play a pivotal role in the smooth functioning of air conditioners. If they break, you could encounter noise issues or higher energy bills, leading to costly repairs.
Replacing this part is relatively affordable and straightforward for a qualified heating and cooling technician, though you might wonder what exactly its function is. But let’s be clear here – capacitors play a critical role!
If you want to hire a technician for your HVAC system concerns and installations, contact a reliable service provider like Hurliman Heating & Air Conditioning.
They Store Energy
Capacitors are devices that store electrical energy for use in AC circuits. Like batteries, capacitors feature two terminals connected by metal plates separated by an insulating material that holds opposite electrical charges – creating an electric field between these plates that can be activated by changing DC voltage levels.
AC capacitors are vulnerable to heat damage and power surges that cause them to overheat, while wear and tear over time, short circuits in an AC system, and age can all shorten their lifespan and necessitate the replacement of worn-out capacitors.
Homeowners can purchase new capacitors through either their HVAC contractor or through big-box stores. Still, they should avoid opening up access panels to their air conditioning unit and trying to change out capacitors themselves. This can be dangerous due to capacitors’ high voltage ratings, potentially harming those in contact.
Instead, homeowners should contact local HVAC companies who will make sure that this task is completed safely and successfully.
They Release Energy
Capacitors store electric energy through positive and negative charges on each plate separated by an insulating material, such as aluminum or mica plates separated by a dielectric material.
As charges attract each other across this dielectric layer and build up until reaching their maximum charge limit based on the surface area of plates and voltage applied, capacitors become powerful energy storage devices.
They are Measured in Volts and Microfarads

Capacitors are measured in microfarads. Each capacitor has a maximum voltage limit that it can handle; exceeding this threshold may damage or destroy it.
Each capacitor also has a leakage current, or how much energy it loses over time, known as leakage current. While leakage current is generally minimal, its presence can reduce lifespan significantly.
Homeowners can test AC capacitors using a multimeter with a capacitance test setting. Before conducting tests, however, homeowners must short the terminals of the capacitor with a long metal screwdriver to discharge any residual energy that remains.
AC capacitors store electrostatic charge between their two conductive plates separated by an insulating material, enabling them to push DC power on and off motors in AC systems – this ability is known as reactance and decreases with frequency while increasing with capacitance – this makes AC capacitors essential – if they begin failing, your air conditioning won’t function properly!
They are Not Batteries
Capacitors differ from batteries because batteries are designed as primary power sources, while AC capacitors don’t. Instead, capacitors give your air conditioning system its initial electricity boost before gradually decreasing its energy output to keep your system functioning efficiently throughout its cooling cycle.
If your AC unit isn’t turning on or running, an HVAC technician could suspect the capacitor to be malfunctioning. A failing capacitor could be responsible for sending warm air through its vents while emitting an audible buzz or producing an unpleasant burning smell in its outdoor unit access panel.
Be mindful that AC capacitors are high-voltage devices that should only be handled by trained HVAC technicians. Even touching one improperly could result in severe injury or death; homeowners should never attempt to test their capacitors without consulting an expert professional.
Also read: What To Do When Your AC Pipe is Frozen in The Summer