Where Are the Evaporator Coils on an AC Unit?

Your air conditioner serves a fairly simple purpose: it delivers refreshingly cool and crisp air into your home or business. If it works, the system keeps all occupants safe and comfortable during the intense summer heat. But to perform this function, the unit relies on an intricate network of components working harmoniously to produce that controlled air, including the all-important evaporator coils.

Where are the evaporator coils on an AC unit, and what exactly do they do? Below, JC Heating & Cooling, the leading AC repair experts in Hodgkins, IL, explain more. Read on to discover how this coil contributes to the heat exchange process so that you can stay cool.

where are the evaporator coils on an ac unit

What Is the Evaporator Coil?

You might think that your air conditioner creates cold air before blowing it through your vents, but only furnaces actually produce air at a certain temperature. Instead, both air conditioners and heat pumps require evaporator coils to draw hot air out of the building. These cooling systems simply draw heat out of the air before circulating it through the network of vents and ducts throughout a building. 

Instead of creating cold air, your property’s cooling system conditions it, and the evaporator coil plays an integral role in the process. Evaporator coils are made of metal, with a series of copper or steel fins surrounding the coils. These fins simultaneously protect the coils and assist in the process of conditioning the air. 

How Does the Evaporator Coil Work?

You might already know that metal is an excellent conductor. It can direct both electricity and heat to and from a specific area. For example, some homes include long metal rods that stick up from the roof of the house to redirect lightning strikes into the ground rather than throughout the house.

Evaporator coils work similarly. Their metal coils attract and redirect heat out of the circulating air. But where does all that heat go?

Although your evaporator coil is integral to conditioned air production, it doesn’t function by itself. Refrigerant circulates inside the coils, assisting the heat exchange process. Refrigerant is a gaseous substance that can remove and release heat from the circulating air.

The refrigerant will circulate throughout another component, the expansion valve, after leaving the coils. Once it has all the heat it can hold, the refrigerant turns into liquid and will more freely flow into the expansion valve to offload that heat. After releasing the heat, the refrigerant becomes frigid again and can absorb more heat, so it flows back into the evaporator coil to continue the process.

In summary:

  • Refrigerant flows into the metal evaporator coils.
  • The metal conducts the heat out of the air.
  • When the heat penetrates the metal, it redirects into the refrigerant. 
  • The refrigerant carries the heat and offloads it into the expansion valve before returning to the evaporator coil. 

Where Are the Evaporator Coils on an AC Unit?

So, where are the evaporator coils on an AC unit? You can find the evaporator coil inside the air handler of a cooling system. Otherwise, you might find it attached to your furnace.

If you want to locate your evaporator coils, the easiest way is to check the owner’s manual for your HVAC system model. It should contain blueprints that show the exact location of the coil. You might also be able to check your manufacturer’s website to find further information about the design of your air conditioning unit. 

Evaporator Coil vs. Condenser Coil: Are They Similar?

If you’ve heard of the evaporator coil, you’ve likely heard of the condenser coil. Although the condenser coil and evaporator coil are two different components, they work in tandem. 

Remember, the refrigerant is a gas at first that turns into a liquid at some point. During its time soaking up the heat in the evaporator coils, it then transforms into a gas again before offloading the heat. 

However, as it offloads that heat in the expansion valve, it travels into the condenser coil. There, it condenses back into its liquid form while the unit releases all the excess heat outdoors. After transforming back into a liquid, the refrigerant returns to the evaporator coils to start again.

Common Problems with Evaporator Coils

Like all appliances, your air conditioner may run into some problems from time to time. Certain parts can sustain damage, which causes problems in how your cooling unit functions. The evaporator coil is among those important parts and will always be on the maintenance checklist for experienced professionals.

What issues could an evaporator coil develop?

  • Freezing: Old, clogged air filters can force your unit to work too hard, freezing the evaporator coil. It will form ice around the metal coils.
  • Debris: Since condenser units are located outdoors, they can catch all manner of debris, which may prevent necessary air circulation. This will also cause freezing.
  • Corrosion: Refrigerants slowly erode the evaporator coil’s metallic coating, forming tiny holes that allow the gaseous refrigerant to escape.
  • Dust: Layers of dust on the coils will suffocate them to cause all of the above issues. 

Without a functioning evaporator coil, your air conditioner produces warm, unconditioned air. Plus, other components become damaged or stop working due to burnout, leading to a growing list of expensive repairs.  

Evaporator Coil Maintenance and Repair

As you can see, it’s best to keep your evaporator coil in top form with services from expert HVAC technicians like JC Heating & Cooling. You can also avoid repair services by scheduling annual HVAC maintenance services as a protective measure for the coils.

During maintenance services, a technician does the following:

  • Remove debris from around the outdoor unit
  • Switch out your air filters
  • Tune up your HVAC system for even cooling and heating

Schedule AC Coil Cleaning Services from JC Heating & Cooling

Where are the evaporator coils on an AC unit? They are usually in the air handler! We hope this brief guide to evaporator coils improves your understanding of HVAC systems.

Be sure to call 708-367-6720 for AC coil cleaning services from JC Heating & Cooling!