A comparison between the aircon cooling coil and the evaporator coil.

The aircon cooling coil plays a vital role in the heat exchange process. As the refrigerant passes through the coil, it releases the accumulated heat and cools down, allowing it to re-enter the system and continue absorbing heat from the indoor air. Without the aircon cooling coil, the air conditioning system would not be able to expel heat efficiently, leading to poor performance and inadequate cooling.

What is the Evaporator Coil?

The evaporator coil, on the other hand, is located inside the air handler or the indoor unit of the air conditioning system. Its primary function is to absorb heat from the air inside the room. The evaporator coil operates in conjunction with the compressor and the aircon cooling coil to facilitate the cooling process.

As warm air is drawn into the indoor unit, it passes over the evaporator coil, which is filled with cold refrigerant. The refrigerant inside the evaporator coil absorbs the heat from the air, causing the air to cool down. The now-cooled air is then blown back into the room. As the refrigerant absorbs heat, it evaporates from a low-pressure liquid to a gas, which is then transported back to the compressor for further processing.

Key Differences Between the Aircon Cooling Coil and the Evaporator Coil

While both the aircon cooling coil and the evaporator coil are essential for the cooling process, their functions and locations within the system differentiate them. Here’s a comparison of the two:

1. Location

Aircon Cooling Coil: The aircon cooling coil is located in the outdoor unit of the air conditioning system. It is positioned outside the home or building, where it can expel the heat absorbed by the refrigerant.

Evaporator Coil: The evaporator coil is located in the indoor unit, typically inside the air handler or near the air filter. This placement ensures that the refrigerant can absorb heat from the indoor air as it circulates through the system.

2. Function

Aircon Cooling Coil: The primary function of the cooling coil is to release the heat that the refrigerant has absorbed from the indoor air. It works by allowing the refrigerant to release its heat into the outdoor environment, where it can be dissipated.

Evaporator Coil: The evaporator coil’s function is to absorb heat from the air inside the room. When warm air passes over the coil, the refrigerant inside the evaporator absorbs the heat, cooling the air before it’s circulated back into the room.

3. Role in the Refrigeration Cycle

Aircon Cooling Coil: It plays a key role in the final stage of the refrigeration cycle. After the refrigerant has absorbed heat from inside the building, it travels to the aircon cooling coil where it expels the heat to the outside. This allows the refrigerant to cool down and return to the compressor for the next cycle.

Evaporator Coil: The evaporator coil is part of the first stage of the refrigeration cycle. The refrigerant enters the evaporator coil as a low-pressure liquid and evaporates into a gas as it absorbs heat from the indoor air. The cool air is then circulated back into the room, providing cooling.

4. Temperature and Pressure

Aircon Cooling Coil: It operates under high pressure as the refrigerant has been compressed by the compressor. As the refrigerant moves through the cooling coil, it is cooled by the outside air and returns to a lower-pressure liquid form.

Evaporator Coil: The evaporator coil operates under low pressure, as the refrigerant inside the coil absorbs heat and evaporates into a gas. This process lowers the temperature of the air passing over the coil.

5. Heat Exchange Process

Aircon Cooling Coil: It performs heat rejection. It expels the heat from the refrigerant, transferring it to the outside air. This allows the refrigerant to cool down and cycle back into the system to absorb more heat.

Evaporator Coil: The evaporator coil performs heat absorption. It absorbs heat from the indoor air and transfers it to the refrigerant, causing the refrigerant to change from a liquid to a gas.

Common Issues and Maintenance

Both the aircon cooling coil and the evaporator coil are subject to wear and tear over time, especially if the air conditioning system is not properly maintained. Here are some common issues that may arise:

Aircon Cooling Coil: Over time, the aircon cooling coil can become clogged with dirt, debris, and dust. This buildup can prevent the coil from efficiently releasing heat, leading to reduced cooling performance and higher energy consumption. Regular cleaning of the cooling coil is necessary to maintain optimal performance.

Evaporator Coil: Similarly, the evaporator coil can accumulate dirt and debris, which can hinder its ability to absorb heat from the air. If the evaporator coil is dirty, the air conditioner may struggle to cool the room, and ice can even form on the coil. Routine maintenance, such as cleaning the coil and replacing air filters, can prevent this issue.

While the aircon cooling coil and the evaporator coil serve different functions, both are essential for the proper functioning of an air conditioning system. The aircon cooling coil is responsible for expelling heat to the outdoor environment, while the evaporator coil absorbs heat from the indoor air to cool the space.