man inspecting outdoor ac unit

What You Absolutely Need to Know About Your Central Air Conditioning System

Your central air conditioning system is one of the most expensive things in your home that you’ll ever need to replace. That’s why it’s essential that you learn the basics about your system, particularly what it needs to run efficiently and last as long as possible.

Below, we’re going to provide you with some “Air Conditioner 101” to help you better understand some basics about your system that will help you save money.


A central air conditioning system is more complicated than a window AC unit because it has more “pieces.” The major components we’ll discuss here are the indoor unit, the outdoor unit, and the ductwork.

The Indoor Unit

Your AC system’s indoor unit contains an essential piece of equipment called the evaporator coil. Your system sucks in hot air from your home and blows it over the evaporator coil, which carries refrigerant. Because the refrigerant is extremely cold, it absorbs the heat from the air blowing over it. This makes the once-hot air cool and ready to be pushed back into your home.

The Outdoor Unit

Your AC system’s outdoor unit (aka. the condenser) also contains a coil necessary for the cooling process. Remember above how the refrigerant in the evaporator coil absorbs heat from your home’s hot air? That refrigerant then travels to the condenser coil to release that heat outdoors.

The Ductwork

Ductwork delivers cold air from your indoor AC unit to the rest of your home. Wherever you see a grate or air register in the wall, floor, or ceiling, you know that there’s an air duct leading up to it. Your home also contains a “return vent.” This is typically where your air filter goes to prevent dust from entering your indoor AC unit.


On average, air conditioning units last for 10 to 15 years. However, with regular maintenance or retrofitting, some units can last 20 years or more. You can do the following for your AC system to keep it running efficiently and help it last as long as possible.

Change the Air Filter Frequently

Though it may seem inconsequential, the air filter can significantly impact the system’s efficiency. When the air filter gets too dirty, it blocks airflow into your AC, which can have several adverse effects, ranging in severity. Your system can even break down from too little airflow. Bottom line: change the air filter at least once every 90 days or sooner (or according to the manufacturer’s directions).

Don’t Block or Close Air Vents

When something obstructs air vents in your home, your system has to work longer to reach your desired temperature. When you completely close a vent, you can cause even more problems by creating a buildup of air pressure inside the system. If you would like more precise control over where cold air goes in your home, it’s best to install an AC system with zone controls.

Get the Air Ducts Sealed

If your air ducts have not been professionally sealed, you could be losing a lot of conditioned air through leaks. In fact, ENERGY STAR reports that in a typical home, “20 to 30 percent of the air that moves through the duct system is lost due to leaks, holes, and poorly connected ducts.” This means that your system ends up running for more extended periods to make your home comfortable, which, in turn, costs you more money and puts premature wear-and-tear on the AC components.

Get Your System Professionally Serviced Once a Year

According to the U.S. Department of Energy, “Neglecting necessary maintenance ensures a steady decline in air conditioning performance while energy use steadily increases.” In other words, if you don’t get your AC routinely serviced, the system won’t work as well and will cost you more to operate.

During the maintenance appointment, the technician will clean the dust and grime off of important components like the condenser coil and evaporator coil so that they can perform their functions more efficiently. The technician will also complete tasks like checking the motor oil and inspecting the unit for any worn parts in danger of failing. The best time to get your AC serviced is usually spring, right before your system is about to go through heavy use.

Let Scott Harrison Plumbing and Heating, Inc. maintain your cooling system so that you can enjoy outstanding comfort all year long without breaking the bank. Call us at (714) 695-5566 to schedule your Orange County AC maintenance appointment today.