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The Fascinating World of Evaporator Coils: Functions Shapes and Performance

When it comes to understanding how your air conditioner or heat pump works, one component that plays a crucial role is the evaporator coil. You may have heard this term before, but what exactly does an evaporator coil do?

In this article, we will delve into the fascinating world of evaporator coils, their functions, and different shapes they can take. By the end of this article, you will have a comprehensive understanding of this essential component in your cooling and heating system.

What is an Evaporator Coil & What Does the Evaporator Coil Do? If you have ever taken a look at the inside of your air conditioner or heat pump, you would notice a radiator-style coil with intricate tubing running through it.

This is the evaporator coil, an integral part of the cooling and heating process. Composed of radiator-style fins and tubing, the evaporator coil is responsible for absorbing heat from the surrounding air or water and transferring it to the refrigerant flowing through the tubes.

The primary function of an evaporator coil is heat absorption. As warm air or water passes over the coil, the refrigerant inside the tubing absorbs the heat, transforming it from a liquid state to a gaseous state.

This process occurs because the refrigerant has a low boiling point, allowing it to take in heat energy rapidly. While heat absorption is the main function, the evaporator coil also plays a crucial role in heat dispersion.

Once the refrigerant absorbs the heat, it travels through the coil and into the compressor, where it is pressurized, causing the temperature to rise. The heated refrigerant is then sent to the condenser coil, located in the outdoor unit, where the heat is released into the atmosphere.

Additionally, the evaporator coil aids in condensation. As the warm air or water comes into contact with the cold coil, moisture in the air condenses on the coil’s surface.

This condensation is collected in a drain pan and directed away from the system, effectively removing excess moisture from the air. The overall cooling or heating capacity of your system is also influenced by the evaporator coil.

The size, surface area, and design of the coil impact the rate at which heat is absorbed and dispersed. Therefore, it is crucial to ensure the evaporator coil is correctly sized and clean to maintain optimal cooling and heating efficiency.

Coil Shapes

Evaporator coils come in different shapes, each with its own advantages and disadvantages. Let’s take a closer look at two common coil shapes –

A-Coils and

N- or Z-Coils.


One common type of evaporator coil is the A-Coil, named after its distinctive shape resembling the letter “A”.

A-Coils have slanted sides and looped refrigerant tubes, allowing for increased surface area.

This increased surface area allows for more efficient heat absorption and dispersion. The design of

A-Coils also makes them relatively easy to clean, ensuring optimal performance.

A-Coils are known for their reliability and have been used in HVAC systems for many years. However, one downside to

A-Coils is their tendency to collect dirt and debris between the loops.

Regular cleaning and maintenance are essential to prevent clogs and maintain efficient operation. Nevertheless, with proper care,

A-Coils can provide excellent performance and reliability.

N- or Z-Coils

Another type of evaporator coil is the N or Z-Coil, named after their zig-zag shape, resembling the letter “N” or “Z”. These coils have multiple rows of zig-zag coils with a third leg of fins between each row.

This design allows for increased surface area, resulting in improved efficiency and enhanced heat transfer.

N- or Z-Coils are known for their efficiency in heat absorption and dispersal. The enhanced surface area ensures that a larger amount of heat is transferred, leading to faster cooling or heating of the air or water passing over the coil.

However, a potential downside to this shape is that the third leg of fins can make cleaning the coil more challenging. The tight spaces can trap debris, making it harder to remove and potentially leading to freeze-ups if not properly maintained.


Understanding how an evaporator coil works and the different shapes it can take is crucial in comprehending the functionality of your air conditioner or heat pump. The evaporator coil plays a vital role in heat absorption, heat dispersion, and condensation.

Whether you have an A-Coil or an N- or Z-Coil, proper maintenance and cleaning are essential to ensure efficient operation. By now, you should have a clear understanding of what an evaporator coil does and the various shapes it can take.

Remember, the evaporator coil is just one component in your cooling and heating system, but it plays a significant role in providing comfort and balanced temperatures in your home.

Slab Coils

Slab Evaporator Coil Features

In addition to

A-Coils and

N- or Z-Coils, another common type of evaporator coil is the slab coil. Slab coils have a compact design, making them suitable for installation in tight spaces, such as attics or closets.

They consist of refrigerant tubes and radiator fin assemblies within a flat, horizontal layout. This layout allows for efficient horizontal airflow across the coil, ensuring optimal heat absorption and dispersion.

One of the advantages of slab coils is their ease of cleaning. The horizontal design makes it easier to access and clean the coil compared to other coil shapes, which may have more complex designs or tight spaces.

Regular cleaning of the coil is crucial to remove dirt and debris, as accumulated debris can hinder airflow and reduce efficiency.

Pros and Cons of Slab Coils

Slab coils offer several benefits and a few limitations. One major advantage of slab coils is the larger surface space they provide.

The flat layout allows for a greater surface area, increasing the contact between the refrigerant and the air or water passing over the coil. This enhanced contact leads to improved heat transfer, resulting in more efficient cooling or heating.

Another advantage of slab coils is their efficiency. The increased surface area, combined with the air or water’s horizontal flow, allows for effective heat absorption and dispersion.

Slab coils are known for their ability to provide consistent and reliable cooling or heating performance. However, there are a few drawbacks to consider.

Due to their compact design, slab coils may have limitations in terms of their cooling or heating capacity. They may not be suitable for larger spaces or areas with high cooling or heating demands.

It is essential to ensure that the slab coil is properly sized for the space it will be installed in to avoid any performance issues.

Goodman AlumaFin7 Coils

Features of AlumaFin7 Evaporator Coil

One notable type of evaporator coil is the Goodman AlumaFin7 Coil. This coil stands out for its exceptional features and construction.

The AlumaFin7 Coil features 7mm refrigerant lines, which allow for more efficient heat transfer. The compact design of the coil maximizes space usage, making it suitable for various installation locations.

The AlumaFin7 Coil also boasts louvered fins, which provide increased surface area for enhanced heat absorption and dispersion. These specially designed fins ensure optimal heat transfer, increasing the efficiency of the cooling or heating process.

Furthermore, the coil’s fins undergo an acid etching process, improving their surface contact and facilitating better heat transfer. To ensure durability and longevity, the AlumaFin7 Coil comes with a heat-resistant drain pan.

This pan is designed to withstand the high temperatures that occur during the cooling or heating process. The heat-resistant drain pan not only protects the coil but also ensures the efficient draining of condensation.

Significance and Awards of AlumaFin7 Evaporator Coil

The Goodman brand is well-known for its commitment to producing high-quality HVAC equipment. The AlumaFin7 Coil is a testament to this commitment.

Goodman strives to inform consumers about the significance of the AlumaFin7 Coil’s features and its impact on overall system performance. The AlumaFin7 Coil has received industry recognition, including the prestigious Dealer Design Award.

This award highlights the innovation and exceptional design of the AlumaFin7 Coil. It is a testament to the coil’s excellence and its ability to meet the needs of both homeowners and HVAC professionals.


Cased and

Uncased Coils

Cased Coils

When it comes to evaporator coils, there are two main types: cased and uncased coils. Cased coils, as the name suggests, come encased in a cabinet.

These cabinets are designed to fit seamlessly with air handlers or furnace installations. The cabinet serves as a protective housing for the coil, ensuring its proper functioning and preventing damage.

One of the advantages of cased coils is the convenience they offer during installation. The coil and cabinet are usually preassembled, saving time and effort during the installation process.

The cased coil is designed to fit perfectly with the accompanying air handler or furnace, providing a clean and streamlined appearance. Additionally, the cabinet surrounding the cased coil serves as an insulation barrier.

This helps to prevent the loss of cool or warm air and contributes to the overall efficiency of the cooling or heating system. The cased coil’s enclosed design also minimizes the risk of dust and debris entering the coil, reducing the need for frequent cleaning.

Uncased Coils

Uncased coils, on the other hand, are coils that do not come with a pre-attached cabinet. Instead, they are designed to be installed in a sheet metal cabinet or in a customized space or design configuration.

Uncased coils provide greater flexibility in terms of installation options and can be tailored to specific requirements. One of the advantages of uncased coils is the ability to customize the installation.

HVAC professionals can design a sheet metal cabinet or configure the coil to fit specific space or design requirements. This flexibility is particularly beneficial when retrofitting or upgrading an existing cooling or heating system.

Uncased coils also allow for easy access and maintenance. Since they are not enclosed in a cabinet, the coil is readily accessible, making cleaning and maintenance more straightforward.

This accessibility ensures that the coil can be regularly maintained, maximizing its performance and longevity.

Questions and Further Assistance

Leaving Replies and Getting Quotes

After reading this article, you may have additional questions or require further assistance regarding evaporator coils or any other HVAC-related matters. It is essential to have reliable sources to seek guidance from and professionals who can provide expert advice and assistance.

If you have any questions or need clarification on any topics discussed in this article, feel free to leave a reply or comment. HVAC professionals or experienced individuals can provide answers and offer further insights to help you better understand evaporator coils and their role in your cooling or heating system.

Additionally, if you are considering installing or replacing an evaporator coil and need assistance in finding the right product or getting a quote, reaching out to local HVAC professionals is highly recommended. They can assess your specific needs, offer product recommendations, and provide quotes tailored to your requirements.

When seeking assistance, it is beneficial to research and choose professionals who are reputable, licensed, and experienced in the HVAC industry. Their expertise and knowledge will ensure that you receive accurate information and reliable recommendations for your HVAC needs.


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