What Is A Condenser On An AC Unit?

An air conditioning unit has several vital components in it that work together to maintain a comfortable temperature inside the property. If all of these components are of good quality, you can trust your system to deliver a good performance. That’s why it’s a good idea to investigate how air conditioning units work and understand the function and purpose of every component. There are four essential components in an air conditioning unit and they are compressor, condenser, meter, and evaporator. All of them work together to ensure the temperature inside your property is cool and comfortable.

What is a Condenser?

A condenser is a component that turns heated and pressurized refrigerant vapor into a cool liquid. This conditioned liquid runs through the air conditioning system and helps cool the indoor temperatures. It also soaks up the heat drawn from the room and transports it back to condenser. Without a good quality condenser, your air conditioning unit won’t cool your property efficiently.

Different Types of Air Conditioner Condenser

AC condensers come in different shapes and forms. Some perform better than others but require a higher upfront investment. Here’s a brief introduction to the options available to you:

1. Air Cooled Condenser

Air cooled condensers are common in residential applications because they’re quite affordable and efficient for cooling small spaces. They’re relatively easy to install and maintain as well, which makes them very appealing to homeowners and small business owners. Here are some of the primary components of it:

•    Condenser Fan Blade – Air cooled condensers draw air from the outdoors and use it to reject heat trapped in the superheated refrigerant vapor. The condenser fan pulls the outside air in and blows it out the heated air.

•    Condenser Motor – The motor is responsible for the fan. It will control the fan’s speed and operation to ensure it blows the air over the coils at the right time and for the right duration.

•    Condenser Coils – They are the most important aspects of the condenser unit. These coils are made from copper, which is a great heat conducting metal. The system pushes the refrigerant through the coils and ensures the vapor cools down to a liquid form.

•    Compressor – Most air-cooled condensers have the compressor in the casing. This saves a lot of space and makes the unit smaller. Unfortunately, that comes at the cost of efficiency. These units take more power and time to cool the refrigerant compared to the other options available in the market.

There are two types of air cooled condensers available in the market and both have their advantages and disadvantages.

•    Fin and Tube Condensers

•    Plate Condensers

2. Water Cooled Condenser

Water cooled condensers are more popular in commercial and industrial applications because they can cool large areas efficiently and consume relatively low amount of electricity. They’re considered more energy-efficient but they have a higher upfront cost and the installation process is a little more complicated as well.

Water is naturally cooler than the air around the AC unit, which helps with the heat transfer process. This system operates at a much lower condensing temperature so it takes less time to cool and consumes very little energy. However, there are some disadvantages of this system as well. You need to have regular supply of water in order for the system to work. You also need to make sure the water is clean and non-corrosive. It should also be of a specific temperature to ensure the refrigerant cools effectively.

Water cooled condenser units are much more likely to develop pitting, algae, mold, scaling, mineral deposits, etc. All of these factors can compromise the efficiency of the system.

•    Tube-within-a-tube – This is one of the most commonly used water-cooled condenser systems because it’s very easy to manufacture. That makes the appliance affordable as well. The double tube design consists of a small tube within larger tube. The small coil carries cool water while the larger tube surrounding it carries the vapor refrigerant. The water and refrigerant run in opposite directions to ensure the latter is cooled effectively. The water draws heat away from the refrigerant and the air conditioning unit and discards it outside.

•    Shell and Coil – This is also a very commonly used condenser system though it’s not as efficient as the double tube system. It consists of a metal shell and a copper coil. This coil contains the cool water while the shell houses the refrigerant. The superheated vapor floods the shell as the system runs cold water through the coils. This process brings the temperature of the vapor down and turns it into a liquid. Unfortunately, shell and coil systems aren’t easy to clean and maintain you need to use chemical agents to flush the debris out of the shell. No matter how clean the water is, it will leave behind some mineral deposits and they need to be removed for the system to work efficiently.

•    Shell and Tube – This is one of the most effective water cooling condenser designs. It consists of several copper tubes placed inside a steel shell casing. These tubes contain the cool water that reduces the temperature of the refrigerant. This unit can be taken apart to clean so it’s easy to maintain. The repair technician can simply remove the shell and clean the coils manually without the need for any mineral and debris deposits.

3. Evaporative Condenser

The evaporative condenser is a combination of air and water cool condensing systems. It’s not as efficient as water cooled condensers but it is a good option for large-scale cooling requirements. Here’s a brief introduction to how these systems work:

•    The superheated vapor from the compressor is circulated through the coils in the system.

•    The water present in the container wets these copper tubes and partially cools the refrigerant inside.

•    The coils emerge from the water container and are exposed to cool air, which causes some of the water on the coils to evaporate. That also works to cool the refrigerant inside until it’s in liquid form and ideal.

There are several advantages of this system that can make it worth the high initial investment. You save a lot of water and don’t have to deal with the common problems of water cooled condensing systems like scaling, mineral build-up, and algae build-up, etc. As the water evaporates as it’s exposed to the air, there’s little to no mineral deposit present on the coils. This system is quite efficient for large-scale industrial appliances and is almost always installed in big commercial buildings and factories.

Evaporator condensers come in two different forms; combined flow and counter flow. In combined flow systems, both the fill surface and condensing coils are used together. The air moves in from the upward direction and passes through the water. The combined flow of both air and water cools the refrigerant and pushes the heat towards the bottom of the tank.

In the counter system, the water moves from the upward direction towards the bottom while the air moves from the bottom to the upward direction. The direction of the flow of water and air is handled by the fans controlled by an external motor. These systems can have two different kinds of fans. The centrifugal fans are considered more efficient because they’re quieter, suitable for both indoor and outdoor applications, and offer compensation for external static. Axial fans require less energy to operate so if cost savings are a concern, you should choose a system with these fans. They’re less efficient and louder than the centrifugal fans because they have large blades that move vigorously through the air. Evaporator systems are a little more complex and sophisticated compared to water cooled and air cooled systems, which is why they’re often used in large scale applications.

You can also use earth cooled condensers but they’re known to be less reliable and more expensive. They’re not easily available in the market so if you have room in your budget, you should consider water cooled systems. They offer the most value for money, especially if you intend to use them to cool large areas.

Detailed Explanation of How the Condenser Works

As explained before, the condenser is responsible for the heat exchange and cools the refrigerant vapor until it’s in liquid form. This is where most of the heat exchange takes place. Here’s a more in-depth explanation of how the condenser works:

•    The primary function of the condenser is to turn the gaseous refrigerant vapor into a cool liquid. When the superheated, high-pressure vapor arrives at the condenser, its passes through narrow condenser coils.

•    At this stage, the blowers blow cool air over the coils to forcefully lower the temperature of superheated vapor. During this process, the vapor turns to high pressure liquid and rejects heat. In water cooled systems, the vapor is cooled by water.

•    The rejected heat is expelled from the air conditioning unit and you can feel the temperature if you place your hand in front of the blow in the external air conditioning unit.

•    The conditioned liquid is transported to the meter and then to the evaporator. In the evaporator, it’s circulated through the coils as a fan blows air past them. This cools the blowing air and helps cool the indoor environment. During this time, the refrigerant reabsorbs the heat from the room and turns back into the vapor state.

This cycle happens repeatedly when the air conditioner is switched on. This entire process is the transfer of heat from your indoor space to the outdoor space.

How Do Air Conditioning Units Work

All components of the air conditioning system play a vital part in this process. For the heat transfer to happen successfully, the unit must follow the laws of thermodynamics. The temperature of the refrigerant should be higher than the temperature of the environment. Here’s a brief glimpse into how it happens:

•    Cooled Refrigerant in the Evaporator – The evaporator component is closest to your indoor environment. The cooled refrigerant liquid passes through the evaporator coils as the fan in the unit blows air past the coils. The air blowing past the coils is quite cool and will bring the temperature of the room down to comfortable levels. The cold liquid will also draw the heat from the room and slowly absorb it. The refrigerant is very reactive and when it’s subject to heat, it quickly turns into the vapor form and moves on. This gives room for newly cooled liquid refrigerant to enter the evaporator once again.

•    Warm Refrigerant Vapor in the Compressor – The vapor travels to the compressor and moves through increasingly smaller tubes. This applies pressure and increases the temperature of the refrigerant vapor until it’s superhot and pressurized. If the compressor doesn’t force the refrigerant to become superhot, the condenser won’t be able to reject the heat and transfer it to the surrounding environment. Heat only transfers from high intensity environments to low intensity environments as per the laws of thermodynamics. If the temperature of the refrigerant is lower than the surrounding temperature of the environment, the condenser won’t work.

•    Heat Rejection in the Condenser – As explained above, water, air, or other components in the condenser draw the heat away from the refrigerant vapor and eject it. This cools the refrigerant and turns it back to a liquid form. The temperature of the refrigerant entering the condenser can be 90 to 105°F higher than the temperature of the surrounding areas. If you touch the copper tubes that carry this vapor, you’ll burn your hand.

•    Controlling Speed and Pressure through the Meter – The meter is simply a checking mechanism that controls the speed at which the refrigerant liquid travels through the system. If the refrigerant travels too quickly through the system, the AC won’t cool the room efficiently. It directs the cooled air to the evaporator and the whole cycle begins once again.

Things to Consider Before You Shop for Condensers in Air Conditioning Units

As you might have noticed, air conditioning units rely heavily on the efficiency of the condensers. However, you don’t need the most sophisticated system available in the market in order to get the cooling you need. Here are some considerations you need to keep in mind before you purchase any appliance air conditioning appliance:

•    Small Areas and Limited Budget – ACs with air cooled condensing systems work efficiently for up to 2 tons. If you just want to cool a small office or a comfortably sized room, you don’t need to invest in the more expensive systems. These air conditioners will work just as you expect them do and deliver a reliable performance. They’ll have a slightly shorter lifespan and the compressor is likely to give up quicker, but the initial investment is quite low so it’s suitable for residential and small commercial applications. Your AC unit will comfortably last for several years.

•    Large Areas – If you want to cool a large house, a small commercial store or shop, or an office floor or building, you should consider AC units with water cooled condensing systems. They’re more efficient and offer better cooling with low energy consumption. In large properties, power consumption is a big concern and inefficient system can add to your monthly expenses. These AC units are worth the larger initial investment because you’ll save a lot of money in the long run. Unfortunately, water cooled systems do require more maintenance so you’ll have to hire a professional to clean, repair, and maintain your air conditioning unit at least twice a year.

•    Big Buildings – Air conditioners with evaporator condensers are a good option for large properties like factories, big office buildings, etc. They consume less power and utilize less electricity. They don’t cool as efficiently as water cooled condensers, but the long-term benefits make them a good choice. They require specialized installation and a lot of space so if you’re on a tight budget and don’t have space to spare on your property, this might not be an option for you.

So if you’re in the market for a new air conditioning unit, you need to consider your budget, the size of the space you need to cool, the amount of outdoor space available, maintenance expenses, power and water bills, cooling capacity, etc. Once you understand your requirements, you’ll have an easier time with the number of options available in the market.

If you understand how the air conditioning unit works and know what role each component of the system plays, you’ll be able to make the right decision during the time of the purchase. If you’re still uncertain, it’s a good idea to ask a professional for advice. They’ll consider your personal requirements and budget before they recommend an air conditioning system that works well for you. They’ll also be more familiar with the popular appliances available in the market.