The Anatomy of a Central Air System

Diagram of air conditioner: compressor, condenser coils, cooling coils, blower, and expansion valve.
Table of Contents

As a homeowner, you must familiarize yourself with your home’s air conditioner to complete central air conditioning maintenance or identify AC problems before calling an AC repair specialist. Taking time to understand the various components of central air conditioning systems and the central air conditioning system working principle will help you keep your system functioning properly for your home. 

So what does the anatomy of a central air system entail? How do the components work to cool your home? And what is their role? Let’s find out!

Key Components of a Central A/C System

A split-system air conditioner essentially means that part of the system is inside, and part of the system is outside. So, what is the inside AC unit called? The part on the inside is known as the cold side, while the outer part is the hot side. To properly maintain your home or a storage unit’s air conditioner, you’ll want to familiarize yourself with its anatomy.

The five elements of the central system of air conditioning include:

1. Evaporator Coil

You can find the evaporator coil in the air handler in a central air conditioner. The refrigerant flowing through the system gets cooled to a low temperature just before entering the evaporator coils, cooling them down. As the warm air from your home enters your HVAC unit, it blows over the cool evaporator coils, which extract the heat, cooling the air down. Fans then blow the cooled air back inside, lowering your home’s temperature.

Ensure that you keep your coils clean as dirt and dust can build upon them over time, reducing their efficiency. Call an AC repair professional to clean your coils yearly for maximum cooling efficiency.

2. Compressor

The compressor is the most critical component in the anatomy of a central air system. For central systems, the compressor is located in the outdoor unit and is usually the most expensive and energy-consuming component.

After the refrigerant absorbs the heat in the evaporator coil, its state changes from a liquid to a warmer vapor. The compressor’s job is to receive the warm refrigerant vapor from the evaporator coil and compress it into a denser, hotter form. 

We increase the refrigerant temperature because it needs to be warmer than the outdoor air to lose heat to the outdoor air. The most critical maintenance tasks to ensure the efficiency of your air conditioner’s compressor are to routinely check for refrigerant leaks, clean your condensing coils, and keep your AC compressor’s exterior clean.

3. Condenser Coil

After the refrigerant’s temperature rises above the outdoor air’s temperature, it flows into another set of coils, called the condenser coils. The evaporator coil works in reverse to the condenser coil. It extracts heat from the refrigerant and ejects it into the outside environment.

After the refrigerant loses thermal energy to the outdoor air, it condenses into liquid form and gets pumped back inside. If you stand outside the exterior unit of your air conditioner, you’ll feel hot air blowing out from it. This is the heat the condenser expels when converting the refrigerant from hot vapor to a hot liquid.

4. Expansion Valve

There’s not much your central AC can do when the refrigerant is in liquid form because, in its current state, it won’t be able to absorb the heat as it circulates through the evaporator coil. This is where the valuable gadget called an expansion valve comes into play. 

The liquid refrigerant enters the valve through a narrow orifice designed to limit the amount of refrigerant flowing through it. As the liquid refrigerant passes through the expansion valve, it experiences a significant reduction in pressure, which causes the refrigerant to expand into a gas. 

The resulting drop in pressure also causes the refrigerant to expand into a mist form. The rapid expansion also throws off a great deal of heat energy, rapidly cooling the refrigerant. This gaseous, cooled refrigerant proceeds into the evaporator coils to repeat the air conditioning process.

5. Thermostat

Thermostats are temperature-sensitive devices that signal your air conditioning system when to start and stop. Programmable and smart thermostats feature advanced settings that help you save energy with automatic temperature changeovers. Consider moving to a more modern unit if you’re still using a mercury-based or digital thermostat. Some of the benefits of pairing central air conditioning with a smart thermostat include:

  • Control your AC from your smartphone
  • It can learn your preferences and build a schedule for you
  • Savings on your energy bills

Smart thermostats might be more expensive than traditional units, but the benefits of using a smart thermostat outweigh the initial start-up costs.

Related Article: How Much Does It Cost to Replace a Furnace and Air Conditioner?

What About the Other AC Unit Components?

If you ever stare at a foreign object and wonder, “what’s that?” Here are some common parts of your central system that you were not quite sure what they were for.

» Air Filter

Air conditioner filters filter pollutants and contaminants such as dust, pet dander, or even bacteria out of the air that passes through them. It is essential to replace these AC filters regularly if you want to enjoy improved indoor air quality.

» Refrigerant

The AC refrigerant is the invisible force behind the working of your central air conditioner. A refrigerant is a chemical compound used in your air conditioner to absorb the heat and provide cool air as it travels through the various components of a central air conditioning system. 

» Fan

An air conditioner fan moves the air from one component to another and blows the conditioned air into your rooms. AC fans also keep your outdoor unit from overheating as they blow the heat away.

» Fan Motors

Fan motors power the fans that pull and push airflow through the AC unit’s coils, ductwork, and living spaces. Like most moving parts, the fan motors should be oiled and cleaned during preventive maintenance each spring. Maintaining the fan motors ensures a long life span, efficient cooling, and minimal AC repair calls.

Summing Up

Knowing a little more about the basic anatomy of your central air conditioning system can help you understand the problem and when you need to call an AC repair technician.

Conejo Valley Home Services are experts within the Conejo Valley, CA, and surrounding areas and can provide top-notch HVAC services. Call us at 805-499-0448 now for all your heating and air conditioning needs.

Related Article: How to Decide Whether Air Conditioner Need Replacement or Repair?

Share This Post:

Your Satisfaction Is Our Promise

What HomeOwners Say About Us

Posted on Google Google
Robert silverman profile picture
Robert silverman
1 days ago
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
EOMASK287034c352e617XGreat job by JuanEOMASK287034c352e618X
Posted on Google Google
Sophia McCabe profile picture
Sophia McCabe
2 days ago
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
EOMASK287034c352e619XGabe fixed the issue with our AC diligently and efficiently. Great customer service, friendly demeanor. Thanks, Gabe, for taking care of us!EOMASK287034c352e620X
Posted on Google Google
Dan Miller profile picture
Dan Miller
2 days ago
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
EOMASK287034c352e621XMy Previous HVAC company was just not treating us as loyal repeat customers. I needed some maintenance service and was given the highest bid of 5 companies. Conejo wasn’t the lowest but they called back right away, they showed up on time, great communication and Sergio our tech found some incorrect assembly of our unit that was leading to us have attic air and some insulation sucked into our unit for the past 8 years! He spent a minute to check the blower and circuit board as we had some intermittent blower issues. Needed a new circuit board. Sergio spent the time and found out it and the blower were under warranty. We just paid a little labor. New warranty on both parts. Thank You Thank you Sergio! I’m calling them next month to come do some minor electrical and plumbing. It’s so great to find a one stop, reliable company for so many home issues. Clean work, on time and great communication!EOMASK287034c352e622X
Posted on Google Google
Christopher Edgar profile picture
Christopher Edgar
2 days ago
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
EOMASK287034c352e623XAndrew was great. Early to the appointment, quick to resolve the AC issue, and understanding as our street was being repaved, which meant he had to park a couple blocks away - and he did need to use his ladder.EOMASK287034c352e624X
Posted on Google Google
David Thomas profile picture
David Thomas
2 days ago
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
EOMASK287034c352e625XGregg was our advisor. Very Knowledgeable and professional. He made time at odd hours and adjusted to our schedule and made sure we were completely comfortable with all questions before we moved forward. Spoke with 5 companies and Conejo/Gregg could not be beat. Highly recommend!!EOMASK287034c352e626X
Posted on Google Google
Thomas Church profile picture
Thomas Church
2 days ago
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
EOMASK287034c352e627XJuan is very knowledgeable and friendly !EOMASK287034c352e628X
Posted on Google Google
Ling Wu profile picture
Ling Wu
2 days ago
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
EOMASK287034c352e629XVery thoughtful, professional and thorough for my annual furnace maintenance service . At the end he summarized with highlights. Thank you very much, Carlos!EOMASK287034c352e630X
Posted on Google Google
Lacey Harris profile picture
Lacey Harris
2 days ago
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
EOMASK287034c352e631XGabriel was amazing. He was extremely knowledgeable and thorough, and completed the work quickly. Everything he did was clean and high quality. Would definitely recommend!EOMASK287034c352e632X
Posted on Google Google
David H profile picture
David H
3 days ago
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
EOMASK287034c352e633XI don't use this company, because I live in Texas, BUT I respect them for immediately firing the man that attacked a little boy. This company has values and so I recommend them. Good job, Conejo Services.EOMASK287034c352e634X
Posted on Google Google
Jeni Gordon profile picture
Jeni Gordon
3 days ago
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
EOMASK287034c352e635XHe was professionalEOMASK287034c352e636X
Posted on Google Google
Helen Wei profile picture
Helen Wei
4 days ago
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
EOMASK287034c352e637XOutstanding service from Conejo Services! We had them replace our large gas water heater, and when the old unit was pulled out, we discovered unexpected water leak damage inside the cubby. Rather than rushing the job, they handled it gracefully by setting up the water heater temporarily so we still had hot water while we repaired the space. They then came back out for a second trip to complete the final, code-compliant installation. They easily could have finished the first day or billed extra for a return visit, but they made two trips and didn’t charge anything additional. Reliable, honest, and truly customer-focused—I wouldn't hesitate to use them again.EOMASK287034c352e638X
Posted on Google Google
Misty Adams profile picture
Misty Adams
4 days ago
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
EOMASK287034c352e639XAwesome company!! Juan was so polite and got everything done perfectly. We’ve dealt with bad companies and this is the OPPOSITE. A+++EOMASK287034c352e640X
Posted on Google Google
Mike Russo profile picture
Mike Russo
4 days ago
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
EOMASK287034c352e641XMy technician, Carlos, was absolutely incredible. He was so friendly and efficient, and as a bonus he took the time to educate me whenever I had questions. What an effortless experience, can’t recommend these guys enough!EOMASK287034c352e642X
Posted on Google Google
William Hamilton profile picture
William Hamilton
5 days ago
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
EOMASK287034c352e643XStarting our second project and the experience has been nothing but great so far. Everyone is very responsive and helpful with all the questions we have hadEOMASK287034c352e644X
Posted on Google Google
Liz Sandoval profile picture
Liz Sandoval
5 days ago
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
EOMASK287034c352e645XJuan came out to do both my heating and cooling maintenance services. Excellent service and very informative in answering my questions on the process.EOMASK287034c352e646X
Posted on Yelp Yelp
Whitney T. profile picture
Whitney T.
6 days ago
Yelp star 1Yelp star 2Yelp star 3Yelp star 4Yelp star 5Verified
EOMASK287034c352e647XAlluron Gipson from Conejo Services was great!! On time, friendly, and went the extra mile to ensure that I was fully satisfied with the job. Would highly recommend Conejo Services.EOMASK287034c352e648X
Posted on Yelp Yelp
J H. profile picture
J H.
6 days ago
Yelp star 1Yelp star 2Yelp star 3Yelp star 4Yelp star 5Verified
EOMASK287034c352e649XOtis was Amazing!!! Had a difficult plumbing job and he problem-solved the issues and completed the job successfully.EOMASK287034c352e650X
Posted on Yelp Yelp
Valerian Z. profile picture
Valerian Z.
6 days ago
Yelp star 1Yelp star 2Yelp star 3Yelp star 4Yelp star 5Verified
EOMASK287034c352e651XOwen was awesome! Super informative, nice, proffesional, and straightforward. Intalled a GFCI outlet, and an exterior outlet, and fixed a few faulty outlets. This was a great experience, and would absolutely use this service again.EOMASK287034c352e652X
Posted on Yelp Yelp
James M. profile picture
James M.
6 days ago
Yelp star 1Yelp star 2Yelp star 3Yelp star 4Yelp star 5Verified
EOMASK287034c352e653XMiguel was thorough and professional. He resolved our plumbing issue very quickly. This company has been great to deal with any time we have needed their service. Highly recommended!EOMASK287034c352e654X
Posted on Google Google
kenneth schild profile picture
kenneth schild
6 days ago
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
EOMASK287034c352e655XRoof tune upEOMASK287034c352e656X
Verified by Trustindex
Trustindex verified badge is the Universal Symbol of Trust. Only the greatest companies can get the verified badge who has a review score above 4.5, based on customer reviews over the past 12 months. Read more