Richmonds Air Houston

License TACLA32064E

Professional AC and Heating Services

Houston's BEST Heating & AC Repair since 2002
5 star ratings Houston AC Repair company Read reviews

Request Service
(713) 732-6426
M-F 7am - 7pm | Sat 7am - 5pm
  • Home
  • About Us
  • Service Areas
    • Houston
    • Bellaire
    • Katy
    • View All
  • Services
    • Air Conditioning
      • AC Installation
      • Whole House Humidifier Installation
    • Heating
      • Heating Repair
  • Learn
  • Blog
  • Reviews
  • Contact Us
Mention these WEB COUPONS when contacting
us to get discount. One offer per customer.
scissors $25 off any repair $100 off new equipment FREE service call with repair
Houston HVAC (Home) / The Heat Beat / Equipment 101 / Parts of a Central Air Conditioning Unit

Components of a Central Air Conditioning System

A complete guide to the different parts of your AC system and how they fit together

How much do you know about your AC system? If you’re like most people, you know enough to change the air filter every few months, and that’s about it.

Your air conditioner and heater is a much more complicated system than most people think.

It’s certainly much more than a glorified ceiling fan. If you’ve ever had a local Houston HVAC professional come to fix an AC problem, you may have discovered that there are numerous parts of your central heat/air system that you hadn’t heard of before.

Why should I care about the basic workings of my air conditioning system?

Understanding how your air conditioner works can be a real superpower for your comfort! Knowing the basics can help you:

  • Identify minor issues early: A little knowledge can go a long way in spotting potential problems before they grow into bigger (and more expensive) repairs.
  • Decide if it’s a DIY fix: Understanding the system might empower you to tackle a quick fix for some simple issues.
  • Communicate better with your AC repair professionals: Even if you can’t fix everything yourself, knowing the lingo will help you explain problems to repair technicians more clearly, saving time and frustration.

Ultimately, by understanding your AC system, you’re taking control of your comfort and saving yourself money in the long run.

Many small but necessary parts make up what we simply refer to as the “air conditioner.” While you certainly don’t have to know each and every one of them, here are five of the most critical parts of a central AC system and how they work to make your home’s indoor temperature comfortable in all seasons:

1. Condenser

The condenser is the outside unit of your air conditioning system. It sits outside on the ground and is typically round or square-shaped.

Here’s what happens inside the condenser: Hot refrigerant gas travels from inside your house, carrying the heat it absorbs.

The condenser acts like a heat exchanger, using a fan and cool outside air to transfer that heat away from the refrigerant. This is based on the scientific principle that heat always moves from warmer to cooler things. That’s why the condenser coils, which look a lot like a car radiator, are usually outside where it’s cooler.

As the AC refrigerant cools down in the coils, it changes into a liquid form, ready to pick up more heat inside your house.

In other words, the condenser works opposite the evaporator coil indoors, which is where the refrigerant absorbs heat to cool your air. Together, they create a continuous loop that keeps your home comfortable.

Condenser

 

 

2. Compressor

The compressor is a large AC component located inside of the condenser and isn’t visible. The compressor is the real workhorse of your AC system.

Think of the compressor as a pump for the refrigerant. It takes the low-pressure, cool refrigerant vapor from the evaporator and squeezes it, raising its pressure and temperature. This high-pressure hot gas is perfect for the condenser to get rid of that heat.

So, the compressor acts like a booster pump, ensuring the refrigerant is always circulating efficiently and ready to pick up more heat from your home.

Compressor

 

 

3. Lineset

The lineset is the lifeline of your AC system, consisting of two insulated copper tubes that connect the outdoor condenser unit to the indoor evaporator coil.

One pipe carries cool, high-pressure liquid refrigerant out to your home, while the other, larger pipe carries the warmed, low-pressure refrigerant gas back to the condenser.

This continuous circulation of refrigerant is essential for your air conditioner to effectively remove heat from your home.

Lineset

 

 

4. Evaporator

The evaporator acts like the magic cooling box inside your home. It’s located within the air handler unit, which is usually mounted on your furnace or near your ductwork.

Here’s where the cooldown happens: Cooler, liquid refrigerant enters the evaporator coil from the condenser. But remember, the expansion valve has reduced the pressure on this refrigerant. Because of this pressure drop, as the liquid refrigerant travels through the evaporator coil, it absorbs heat from the air around it, turning it back into a gas. This process is what cools the air inside your home.

Once the refrigerant has absorbed heat and become a gas, it travels back outside to the condenser to start the cooling cycle all over again. This continuous circulation keeps your home at your desired comfortable temperature.

Evaporator

 

 

5. Expansion valve

Think of the expansion valve as a tiny control valve placed strategically in the line carrying refrigerant to the evaporator coil. This valve plays a crucial role in maximizing the cooling process.

Here’s why it’s important: High-pressure liquid refrigerant leaving the condenser is still quite warm. The expansion valve cleverly reduces the pressure on this liquid refrigerant as it enters the evaporator. This pressure drop has a surprising effect – it causes the refrigerant to absorb a significant amount of heat from its surroundings in order to turn back into a gas. This is the magic that allows the evaporator coil to draw heat out of the air in your home.

So, the expansion valve acts like a conductor, controlling the pressure of the refrigerant to ensure it absorbs heat efficiently in the evaporator coil.

Expansion valve

 

 

Other components

So, that covers the main components that work together to keep your home cool: the condenser, compressor, lineset, evaporator, and expansion valve. But there are a few other important players to remember:

  • Thermostat: This is the brain of your AC system, constantly monitoring the temperature in your home and turning the cooling process on or off based on your desired settings.
  • Air filter: As your air conditioner pulls in air to cool it, the air filter acts like a guardian, trapping dust, pollen, pet dander, and other particles before they can recirculate back into your home.

Changing your air filter regularly is essential for both your comfort and the smooth operation of your AC system.

Remember, all these AC components work together to keep you cool. Regular maintenance can help ensure each piece is functioning properly and prevent any problems from derailing your comfort this season.

Explore more:

To learn more about what a full-service AC inspection typically covers, check out our blog post: What Should a Full-Service AC Inspection Include?

Talk to a Houston HVAC expert at Richmond’s Air

If you’re in the Houston area, contact the professionals at Richmond’s Air if you notice any problems or just want to make sure everything is running smoothly. We offer maintenance, repair and cleaning for every component of your system.

Contact us today

Visit Our HVAC Repair & Maintenance Blog Learn More
8 Air Conditioning Problems You Can Prevent With Proper Maintenance View Article

Get a FREE AC Tune-Up!

Get a FREE AC Tune-Up!

AC maintenance season in Houston is here! Richmond’s Air is proud to participate in CenterPoint® Energy Houston’s CoolSaver program to offer you a complimentary AC tune-up. This tune-up can save you money on future repairs as well as increase your system’s efficiency and cooling output by up to 27%.   Find out if you qualify


Facebook Twitter Blog Contact
Richmond's Air $$$ Air Conditioning Service and Maintenance
Richmond's Air: 5 Rollingwood Dr  Houston, TX 77080    (713) 999-4735
Hours: Monday to Friday: 7am – 7pm    Saturday: 7am – 5pm    Sunday: Closed

Houston HVAC Services From a Local Company You Can Trust. Serving Houston, TX and surrounding areas: Katy, Bellaire, Spring, Cypress.
Our neighboring ZIP codes: 77024, 77056, 77005, 77019, 77030

 

Find Us on Angie's List

Richmond's Air BBB Business Review TACCA Membership

Copyright © 2026 · Web Design & Marketing by SEO Advantage, Inc.

Heater and Furnace Questions Answered
View Article