One of the questions our AC technicians have been asked many times over the years is, “What does a condenser do?” This is a good question, and we believe that residential and commercial customers should understand how their HVAC systems work to provide a comfortable environment. By understanding how your cooling system works, you can have a good idea of what may be wrong when it isn’t working as it should.

Many people aren’t too concerned about the components of their air conditioning and heating systems as long as everything is functioning properly. It’s when something goes wrong that they may learn about the various parts of their systems and what these components do to keep it all running smoothly!

Before we explain what a condenser does, let’s first talk about what a condenser is. Whether you have central AC or a heat pump, the condenser is the portion of your system that is placed outdoors. Depending on the season and temperatures, the condenser either collects heat (when it’s hot outdoors), or releases heat (when it’s cold outdoors). At its most basic, the condenser transfers heat.

If you look at the condenser cabinet portion of your system outdoors, you can usually see part of the fan. Other components in the cabinet that aren’t easily visible include the compressor, condenser coil, and a variety of controls. The condenser coil allows for rapid heat transfer and may consist of all-aluminum tubing, or copper tubing combined with aluminum fins. The compressor is the most vital component of your condenser, as it is responsible for compressing refrigerant and pumping it to the condenser coil as a hot gas.

Now to the big question:  What Does a Condenser Do?

There are three very important functions the condenser performs in keeping your air conditioner performing its best. These include rejecting superheated refrigerant gas, condensation, and subcooling refrigerant once it is transformed back into a liquid state.

Let’s talk about some of the components inside the condenser so it makes a bit more sense.

The compressor receives refrigerant from the inside unit of your home and adds pressure to it so the refrigerant’s temperature rises, making it easier to transfer heat from inside your home as an important first step of the cooling process. Refrigerant absorbs the heat in the air inside your home before leaving the evaporator coil as a gas. Next, it enters the compressor where the refrigerant’s temperature rises as it’s “compressed” tightly together. The function of the condenser is to lower the temperature of the refrigerant so it can be converted back into liquid form.

Next, the refrigerant flows through the condenser coils which are cooled off by the fan before being released into the outdoor air. During this stage of the process, the refrigerant circulates continuously and passes multiple times through the condenser. As the process goes on, the fan rapidly cools off the heated air and releases it to the outdoors. When the refrigerant reaches a certain temperature (below the saturation temperature, which we explain below), it converts into liquid form (condensation).

Refrigerant lines located in the condenser continue the process of cooling by cycling refrigerant between indoor and outdoor units.

The condenser works to continuously cool refrigerant below its saturation temperature, making it more effective. If you are wondering what we mean by saturation temperature, this term refers to the moment a liquid transforms into a gas – a relationship between pressure applied (compressor) and a liquid’s boiling point.

As the condenser continues the process (referred to as subcooling), the refrigerant becomes stable and remains in liquid form as it continues the cycle returning to the inside evaporator coil.

During the colder winter season, the condenser collects heat from the outdoor air to heat your home, working somewhat in reverse. Cooling and heating your home is all about heat transfer, whether in or out.

To put it simply, without the condenser unit the hot air that is pulled from the air inside your home wouldn’t have anywhere to go. Hopefully we have helped make the answer to “What does a condenser do” a bit more clear!

How do you know if your condenser unit has serious issues or is on the brink of failure? Common warning signs include a substantially larger amount of fluid leaking from the unit beyond what you would think is normal condensation, substantially reduced cooling from your AC system, or unusual/loud noises coming from the outdoor unit. If you notice any of these things or another issue that has you concerned, call the professionals right away.

Many people ignore the outdoor condenser unit, but it is vital to take care of it so that it functions properly and has a longer lifespan. The buildup of dirt, dust, leaves, sticks, and other debris should be removed so the unit can run freely. Also keep shrubs, plants, partitions (such as wood fences) and other objects a minimum of three feet away from the condenser so that it has access to proper airflow. If possible, keep dogs away from the condenser as male dogs have a tendency to hike their leg on any object they pass by.

The absolute best thing you can do to ensure your condenser unit stays in good functioning order is to schedule annual maintenance. At Schneider Mechanical, our Austin air conditioning professionals will thoroughly inspect your condenser for any minor issues that could become a major (and costly) headache in the future. Have questions about the condenser unit that we haven’t answered here, or need to schedule a check-up? Give us a call today.