The Basic HVAC Condenser Coil: They Work Like This

How Do Condenser Coils Work?

In terms of heating, ventilation, and air conditioning systems, it has become a necessity today to have them in every household, regardless of which country you are in.

From household residences to different industry offices, it has become a dependable machine that helps many people stay comfortable in hot or cold weather.

One of the important processes of heating and cooling takes place in the condenser coils, which many homeowners don’t know about.

How do condenser coils work? The heat is removed from the refrigerant inside the condenser coil. After the gas refrigerant is heated and pressurized in the compressor, it will enter the condenser coil. Then, the gas refrigerant transfers its heat to the air blowing over it.

Read on to learn about the importance of coils in your HVAC systems and, most importantly, what role condenser coils play in all this machinery.

I will also include a section where you can learn basic maintenance for your condenser coils to keep them running efficiently.

The Basics of How Your AC Works

While you might think that your home air conditioner is responsible for creating and delivering cool air into your home, think again.

It actually works by transferring hot air out of your indoor space. Your system has an insider unit, which is called an air handler, and inside your air handler is the evaporator coil.

On the other hand, your system’s outside unit holds the compressor, condenser coil, and blower fan.

Connecting both the outside and inside units are tubes and pipes that carry the coolant, most commonly known as refrigerant.

When your refrigerant is inside your evaporator coil, it becomes very cold and can absorb all the hot air from inside your home.

The hot refrigerant then travels back to the outside unit, where the hot air gets expelled to the outside.

The coolant then comes back into the evaporator coil, where it gets chilled and can absorb even more heat. This becomes a continuous cycle and is basically how your air conditioner works on the inside.

The Condenser Coil

The condenser coil is actually similar to the design of the evaporator coil. The only difference between a condenser coil and an evaporator coil is that they are reversed.

As you know, the evaporator coils pick up the heat from the indoor air. The condenser coil, on the other hand, releases heat into the outdoor air.

A load of heat energy is extracted from your indoor space and the compressed in the hot refrigerant vapor is rapidly released when the refrigerant circulates into the coil. As a result of this action, it condenses into a liquid.

As the refrigerant releases its heat load, the fan that is present in the outside unit will blow through the condenser coil passages and will disperse heat into the outdoor air.

The high-pressure liquid refrigerant will leave the condenser coil to make a U-turn and flow back to the evaporator coil. Then an expansion valve before the evaporator coil will restrict the flow of refrigerant.

This will force it through a narrow orifice and then convert it back to the vaporized state, ready to absorb more heat energy from your home.

Condenser Coil Design

As you have learned, condenser coils are used to reject heat from an air-conditioning or refrigeration system. They are sometimes used to heat air streams, and they are one of the four main components in most air-conditioning cycles.

Condenser coils are used mainly for heat rejection, reheating, and some comfort heating. They come in many shapes and sizes, but some properties are most common in many condenser coils:


Many condenser coils have a very large surface area and a fairly high air-to-refrigerant-temperature reference. This is because there are only a few rows that are generally required. You should expect to see a condenser coil that is between 1 to 3 rows deep.

Tube Diameter

Many condenser coils should be able to handle a significant amount of internal pressure. With some R-410a, working pressures can reach as high as 600psa. Smaller tube diameters can handle this kind of pressure efficiently.

They can also help ensure that refrigerant velocity is high enough to keep oil moving through the coil. Normally, the size of a condenser is within the ⅜” tubes.


Connections for most refrigerant applications are normally copper sweat. Other types of connections are more prone to leakage. This is a common problem when working with refrigerants.

How Does a Condenser Coil Work?

To understand how your air conditioner condenser coil works, you need to understand its main function. It is a place where all the warm air gets removed, and the aircon condenser coil mostly works for the heat transfer process.

This AC component is where much of the absorbed heat is transferred from your house to the open outdoors.

An AC condenser coil is made from different tubes and is filled with refrigerant liquid. For it to be able to do its job, a chiller inside the coil cools the fluid, which moves through the condenser tubing.

Once this process is over, it is further converted into gas, and the converted gas is distributed throughout your cooling system. Once this conversion process is finished, the refrigerant will release the heat and return to a liquid state. This is a cycle, and it will continue in a closed system.

If you look closely into a condenser coil in terms of how it processes all of this, you will see the refrigerant vapor process. This vapor is normally processed through a cycle of the warm trading loop.

This allows it to turn into liquid and dismisses the heat from the cold indoor space in the process. The aircon is most likely to provide you with the quality air that every homeowner and office worker expects to get from this condenser coil process.

Caring for Your Air Conditioning Condenser

You don’t need an HVAC technician to tell you whether your AC machine deserves proper and regular maintenance and check-up. Whether you are having issues with your overall AC unit, condenser unit, or evaporator coil, knowing when to call for help is crucial.

For your AC to perform on the right track and at its absolute best, you must schedule frequent appointments with your HVAC technician. If you do this regularly, you can save a lot of money by preventing any bigger performance issues down the road.

Keeping the Condenser in Shape

Regular checkups and good airflow are both critical for evaporator coils and condenser coils. This is because both of these components transfer heat, and debris or any kind of dust can interfere with their ability to do their primary job.

For most condenser units, the most common threat is the buildup of yard debris on the fins. Usually, this takes the form of grass clippings, fallen leaves, twigs, and sometimes pet hair that make it harder for the condenser to release heat.

This reduces your AC’s energy efficiency and can place a strain on the condenser and your other HVAC components. It is recommended to check the condenser periodically, and if you notice any major buildup, you should shut down the power. Then gently use a stiff brush and clean your fins. 

It is also worth mentioning that an air conditioner condenser can develop frost and even a complete casing of ice on rare occasions.

Assuming that your condenser is clean, ice-ups like this usually mean that there is an airflow problem elsewhere in your system. It could be from dirty air registers, air filters, and vents.

If there is ice on the condenser, it can be caused only by low refrigerant, which requires a professional’s intervention.

Importance of Cleaning the AC’s Condenser Coil

Your air conditioner is a complex machine with multiple components that work together. Most components of an HVAC system work hand in hand to ensure that your home is comfortable regardless of whether you want it to be cool or warm. If you have an issue with a single part, it can drag down the whole system, causing damage.

This is why it is very important to have a proper cleaning and maintenance schedule for your air conditioner. To get the most out of your air conditioner, it is also important to regularly clean the outdoor condenser coil.

What the Outdoor Unit Does

To understand the importance of the condenser coil, it helps to know how your overall AC works. Your AC is the one responsible for moving the heat out of your home; then it replaces the heat with cool air.

All the hot air flows over to your evaporator coils, where the refrigerant absorbs all the heat. This causes it to evaporate. Special conduits then carry that case to the outdoor unit.

The outdoor unit has a special pump, called a compressor, that forces the gas under high pressure to return to its liquid form. Also, the extra heat created in this process is passed down outdoors via your condenser coils.

As a result of this behavior, the gas cools down and changes back to its liquid state.

How Cleaning Helps

Because your outdoor unit’s main purpose is to release the heat outside your home, good airflow is essential. If you have a better airflow, your air conditioner will more efficiently get rid of the stored heat.

As a result, it can improve the performance of the system as a whole. Because your outdoor unit can be found outside the house, it can be exposed to different elements.

Keeping your outdoor unit clean means you need to brush off the dust, pollen, and dirt, as well as clean off any debris that might have fallen onto or into the unit. You will also want to cut back some of the foliage within a few feet of your system.

Also, ensure that there are no objects or landscaping within two feet of your outdoor units on all sides and within five feet of the tip of the unit.

Ensuring that the exterior portion of the unit is clean is very simple, but it’s best to leave the cleaning of coils and other interior components with the professionals.

Constant maintenance will ensure that your condenser coils stay in good and working condition.

How Often to Clean

When it comes to cleaning and maintenance, your outside unit should be cleaned at least once a year. It varies from area to area because some places have more extreme weather than others. The good news is, coil cleaning is a standard protocol of preventive maintenance for your air conditioner.

During maintenance, your technician will also take care of and straighten out any of the condenser’s fins that may have gotten bent since your last maintenance routine.

Bent fins usually are the prime causes of restricted airflow. This means that straightening them can maximize your condensing unit’s efficiency.

The Purpose of Maintaining Your Condenser Coil

Your condenser coil’s main purpose is to transfer heat collected from your indoor spaces into the outside air.

However, this main purpose is not delivered if the condenser coil can’t exchange heat with the atmosphere, if it is covered in dirt, or if its cooling fins are bent. The good news is that cleaning the condenser coil is not difficult.

You only need to gather a few tools and materials before the cleaning process. For instance, you will need to have a vacuum, a pump-up garden sprayer, coil cleaning solution concentrate, a garden hose, pruning shears, and a condenser comb. Here are some ways to do it properly:

Turn off the Power

The first step is to clear off any power source that is connected to your air conditioning unit. Do this by disconnecting the electrical power at the main breaker panel or the outdoor unit switch.

Do not simply turn off the thermostat. Otherwise, someone may turn it on without noticing it.

Clear Plants and Weeds

Next, remove all the plants and weeds. Use a pair of pruning shears to clip any plants that might be growing too closely to your condenser coil. Foliage can interfere with any heat exchange processes.

Vacuum Loose Debris

Once you get rid of any plants or weeds, it is time to clear away some of the loose debris covering your condenser coil. This debris consists of dead grass, leaves, seeds, and all kinds of small bits and pieces of trash.

To clean them, use a sharp vacuum crevice tool to reach into the narrow spaces between the protective grille and condenser coil.

Spray the Condenser Coil With Cleaner

You need to spray your condenser oil with some kind of cleaner. When mixing a coil cleaning solution, follow the instructions on the label.

Avoid splashing it on your face or eyes, as it contains harmful chemicals that are not good for the body. Fill a pump-up garden sprayer with the solution and begin spraying the exterior of the condenser coil.

Continue to spray until all sides of the coil are covered with the solution. Then wait for 5 minutes.

Rinse the Coil With Water

Once your condenser coil has soaked in the cleaning solution for over 5 minutes, you can proceed with the garden hose and rinse the chemical residue from the coil. Never point a forceful stream of water against your coils, as this can damage the fins.

Comb the Condenser Coil Fins

The last step is to straighten the fins. You can use a fin comb to do this. Slowly brush the fin comb downward from the top of the unit. Not all fins will be straightened, but you can achieve a marked improvement in their ability to exchange heat by fixing some of them.


Condenser coils are considered to be among the most important components of any heat, ventilation, and air conditioning system. To maintain and clean this AC component in a proper way, you need to know how it works and what the needed precautions are when doing so.

Condenser coils are important to ensuring that your home or workplace gets a clean and comfortable temperature, keeping its occupants comfortable.

Recent Posts