Summers feel more intense each year, so it’s no surprise that 90% of Americans lean on air conditioners to help them survive the heat. But although nearly everyone depends on their smooth operation through the season, there aren’t many people who know what goes on behind the scenes.

Understanding your air conditioning is essential if you want to properly maintain it and identify issues as they happen. 

The compressor and condenser in air conditioning systems are two of the most important components in cooling your home. These pieces make up the outdoor half of central and split systems. In this article, we’ll explain the difference between a compressor and a condenser to help you understand how they work to keep your home cool.

The Basic Air Conditioning Process

There are four basic components of an air conditioning system:

  • Evaporator
  • Compressor
  • Condenser
  • Expansion valve

These pieces exist in a circuit connected by tubes full of refrigerant. Refrigerant is the heat transport system, a unique fluid that transitions between liquid and vapor depending on where it is in the system.

Starting at the evaporator, the refrigerant absorbs heat in the evaporator coil as warm household air passes over it. The cooled air is then blown back into the house.

The warm vapor moves to the compressor, which adds pressure to the refrigerant and pumps it to the condenser coil. The condenser coil releases heat into the outside air, and the refrigerant cools down.

The refrigerant leaves the condenser and flows to the expansion valve. The expansion system depressurizes the refrigerant, making it a cool, low-pressure liquid. The liquid then moves back to the evaporator, ready to absorb more heat and start the process all over again.

What Is an AC Compressor?

The compressor works with the condenser in air conditioning units to release heat into the outside air. Its job is to pressurize the refrigerant.

The process not only increases the heat of the refrigerant but also pumps the fluid through the system. You can think of the compressor as the heart of an A/C system.

How a Compressor Works

Compressors are metal containers with two openings, one that sucks in refrigerant coming from the evaporator and one that discharges pressurized refrigerant to the condenser coil.

There are a few different types of A/C compressors. The most common is a reciprocating compressor.

In a reciprocating compressor, a piston moves up and down within a cylinder while the unit is on. When it moves down and opens space in the chamber, it creates suction and draws in the warm refrigerant.

The piston then moves back up into the cylinder, decreasing the volume of the gas, thus compressing it. Once the gas reaches a certain pressure level, the discharge valve opens and the pressurized fluid is shot into the condenser coil.

Why Refrigerant Needs Compression

When gas is pressurized, it creates heat, which is essential for the condenser to do its job. Refrigerant works through heat exchange, where it tries to balance its temperature with the surrounding air.

If the air is cooler than the refrigerant, the refrigerant will expel heat into the air and cool down. Since we use our air conditioners during the summer, the outside air can be quite hot, meaning the refrigerant needs to be even hotter.

The heat transferred from household air in the evaporator coil is not enough to make the refrigerant hotter than the outdoor air. By pressurizing the vapor, the compressor builds energy in the refrigerant and makes it extremely hot. Even if you’re trying to keep cool on a 100-degree day, the compressor ensures the refrigerant is always hotter than the outdoor air.

After it leaves the compressor, the refrigerant goes to the condenser, where the cooling process can begin.

What Is a Condenser in Air Conditioning Systems?

The term “condenser” is a general reference to the outdoor metal box that houses the condenser coil, fins, outdoor fan, and compressor. It’s called a condenser because this is where the refrigerant condenses back into liquid, whereas, in the evaporator, it turns to a gas.

The condenser coil wraps around the perimeter of the box. It’s hard to see because it is hidden behind a vast network of thin, fragile metal fins, which make up the walls of the unit.

How a Condenser Works

The refrigerant in the copper condenser coil needs to cool down through a thermal exchange with the outside air. The temperature difference between the two is enough to initiate the process, but the condenser coil has two vital helpers — the metal fins and the outdoor fan.

The outdoor fan helps by giving the condenser coil a constant supply of cool air so it can release heat. Meanwhile, the metal fins conduct heat from the copper condenser tube.

There are hundreds of fins around the wall of the condenser unit, creating an enormous amount of surface area. They expose the refrigerant’s heat to the outside air, giving it more points for the heat exchange process to take effect.

With a powerful fan blowing cool air and the high surface area of the fans transmitting more heat, the condenser efficiently cools down the refrigerant. 

Maintaining Your Condenser

When the fins or the fan are not working as they should, you’ll notice the air entering your home is not as cold as it should be. The refrigerant isn’t able to cool down as effectively. As a result, the liquid that enters the evaporator does not have a significant temperature difference with the incoming household air, and it can’t absorb as much heat.

If the system’s blowing warm air, check to see if the condenser fan is turning. If it isn’t, you may have a bad motor. Contact a service technician if you feel you’re having issues with your motor or compressor.

While you may need professional intervention for mechanical problems, you can clean your condenser coil to keep the fins clear. By removing dirt and debris, the fins won’t be insulated from the outside air and can transfer heat more efficiently. The refrigerant will cool down more, and your evaporator will be able to extract more heat from the air inside your home.

Stay Aware of Your Compressor and Condenser

Our Texas summers are some of the hottest you’ll find, so your air conditioning must work as efficiently as possible. Now that you know how the compressor and condenser in air conditioning units work to cool your home, you’ll be able to tackle your seasonal maintenance with a little more confidence.

When your compressor or condenser fails, you’ll immediately notice the temperature start to rise. If you want to beat the heat as soon as possible, contact our professionals at Schneider Mechanical for speedy 24/7 emergency service in Austin.