What Is an Outdoor AC Unit Called and How Does It Work?

When it comes to cooling your home, there are many terms and components involved that can be a bit confusing, especially if you’re not familiar with how air conditioning systems work. From compressors to evaporator coils, it’s easy to get lost in the jargon.

But understanding the key parts of your AC system – especially the outdoor unit – can help you when it’s time to buy a new system or schedule a repair. HVAC.com breaks down what the outdoor AC unit is called, its components, and how it works in conjunction with the indoor unit to keep your home cool.

What Is the Outdoor AC Unit Called?

The outdoor unit of an air conditioning system is commonly referred to as the condenser unit. It’s an essential part of a central air conditioning system that works alongside the indoor unit, which includes the evaporator coils and air handler. The condenser unit is responsible for releasing the heat that your AC has absorbed from inside your home.

While “condenser unit” is the most widely used term, you might also hear it called the “outdoor compressor unit” or “AC condenser.” These terms all refer to the same piece of equipment that sits outside next to your home, typically mounted on the ground or on a platform.

Key Components of an Outdoor AC Unit

The outdoor unit consists of several important components that work together to ensure efficient cooling. Here’s a quick breakdown of what’s inside:

Compressor

The compressor is often considered the heart of the outdoor unit. It takes the refrigerant that has absorbed heat inside your home and compresses it to a high pressure. This process increases the temperature of the refrigerant, turning it into a hot gas.

Condenser Coil

After the refrigerant is compressed, it moves into the condenser coil, where the heat is released into the outside air. The condenser coil is a series of copper or aluminum tubes that allow the refrigerant to cool down and return to a liquid state. This heat exchange process is essential for cooling the air inside your home.

Fan

A large fan is located within the outdoor unit to blow air across the condenser coils. This helps carry away the heat from the refrigerant, allowing it to cool and condense back into a liquid.

Refrigerant

Refrigerant is the substance that moves heat from inside your home to the outdoor unit. It cycles between liquid and gas states as it moves through the system.

How the Outdoor Unit Works with the Indoor Unit

The outdoor unit doesn’t work alone – it’s part of a larger system that includes the indoor unit, where the cooling process actually begins. Here’s how the two parts work together:

1. Absorbing Heat Inside: The cooling process starts in the indoor unit, where the air handler blows warm air over the evaporator coils. The refrigerant inside the coils absorbs the heat from the air, causing it to evaporate into a gas.
2. Transporting Heat to the Outdoor Unit: The refrigerant, now in gas form, is pumped through copper tubing to the outdoor unit. As it travels to the compressor, it begins the process of being compressed into a hot gas.
3. Releasing Heat Outside: Once the refrigerant reaches the outdoor unit, the compressor pressurizes it and the refrigerant moves through the condenser coil. Here, the heat is released into the outdoor air with the help of the fan. As the refrigerant cools, it turns back into a liquid, ready to return inside to absorb more heat.
4. The Cycle Repeats: This cycle continues as long as your AC system is running. The indoor unit keeps pulling in warm air, and the outdoor unit works to release the heat outside, maintaining a cool and comfortable environment inside.

Why Understanding the Outdoor Unit is Important

Knowing what the outdoor AC unit is called and how it works can be helpful for homeowners for several reasons:

• Troubleshooting: If you’re experiencing issues with your air conditioning, understanding the outdoor unit’s role can help you explain problems to a technician. For example, if your outdoor unit isn’t running or making strange noises, it could be a sign of a malfunctioning fan, compressor, or refrigerant issue.
• Maintenance: Regular maintenance of the outdoor unit helps keep your AC system running efficiently. Homeowners should have professional maintenance performed annually, ensure there’s no debris blocking the airflow, and check for signs of wear and tear. This can help extend the life of the system and prevent costly repairs.
• Repairs and Replacements: If your outdoor unit needs a major repair or replacement, knowing its components and functions can help you make an informed decision when talking to an HVAC professional. You’ll be better equipped to understand what’s being repaired or replaced and how it affects the overall system.