Why Only the Bottom Half of the Evaporator Coil is Cold?

The evaporator coil is a crucial component of an air conditioning system, as it is responsible for absorbing heat from the air inside a building and transferring it to the refrigerant. When the evaporator coil is not functioning properly, it can lead to problems with the overall performance of the air conditioning system.

One common issue is when only the bottom half of the evaporator coil is cold. This can occur for a variety of reasons, and it is important to diagnose and fix the problem in order to ensure that the air conditioning system is working efficiently and effectively.

In this article, we will explore some of the potential causes of this problem and provide some solutions for fixing it.

Only Bottom Half of Evaporator Coil is Cold Problem

It’s important to make sure that the refrigerant levels are correct and that the expansion valve is functioning properly in order to ensure that the system is working efficiently and effectively.

To determine the correct reading for the refrigerant levels in your system, it’s important to consult the manufacturer’s specifications for your specific unit. These specifications will typically provide information on the recommended refrigerant levels for your system based on the size and capacity of the unit. It’s also important to note that different refrigerants have different pressures, so it’s important to make sure that you are using the correct refrigerant for your system.

If you are unsure about the correct refrigerant levels or if you suspect that there may be a problem with the expansion valve, it’s a good idea to have a professional HVAC technician take a look at your system. They will be able to diagnose any issues and recommend the appropriate course of action to fix the problem.

Possible Causes of the Problem

There are several possible causes that could lead to only the bottom half of the evaporator coil being cold.

Low Refrigerant Levels

One potential cause is low refrigerant levels. When the refrigerant levels are low, it can lead to a lack of sufficient refrigerant flow through the evaporator coil.

This can result in an insufficient amount of heat being absorbed by the refrigerant, which in turn can lead to only the bottom half of the coil being cold.

Restricted Refrigerant Flow

Another potential cause of this problem is restricted refrigerant flow. This can occur when there is a blockage or restriction in the refrigerant lines, which can prevent the refrigerant from flowing freely through the system. This can also lead to an insufficient amount of refrigerant flowing through the evaporator coil, resulting in only the bottom half of the coil being cold.

Faulty Thermostatic Expansion Valve

A faulty thermostatic expansion valve (TXV) can also cause this issue. The TXV is responsible for controlling the flow of refrigerant into the evaporator coil. If it is not functioning properly, it can lead to an imbalance in the amount of refrigerant flowing through the system, resulting in only the bottom half of the evaporator coil being cold.

Clogged Air Filter

A clogged air filter can cause this problem. When the air filter is clogged, it can restrict the flow of air through the system, which can lead to an insufficient amount of heat being absorbed by the refrigerant in the evaporator coil. This can result in only the bottom half of the coil being cold.

How to Diagnose the Problem

To diagnose the problem of only the bottom half of the evaporator coil being cold, there are a few steps that you can take.

Check the Refrigerant Levels

First, you can check the refrigerant levels in the system. If the levels are low, it could be causing the problem.

You can check the refrigerant levels using a refrigerant pressure gauge.

Inspect the Refrigerant Lines

Next, you can inspect the refrigerant lines for blockages or restrictions. These can prevent the refrigerant from flowing freely through the system, leading to problems with the evaporator coil. To check for blockages or restrictions, you can visually inspect the lines and look for any visible signs of damage or obstruction.

Test the Thermostatic Expansion Valve

You can also test the thermostatic expansion valve (TXV) for proper function. If the TXV is not functioning properly, it can cause an imbalance in the flow of refrigerant through the system, leading to problems with the evaporator coil. You can test the TXV using a refrigerant pressure gauge and following the manufacturer’s instructions.

Check the Air Filter

Finally, you can check the air filter and replace it if necessary. A clogged air filter can restrict the flow of air through the system, leading to problems with the evaporator coil. Simply replacing the air filter can often fix this issue.

By following these steps, you can diagnose the problem and determine the appropriate course of action for fixing it.

How to Fix the Problem?

Once you have diagnosed the problem of only the bottom half of the evaporator coil being cold, you can take the appropriate steps to fix it. If the problem is low refrigerant levels, you can add more refrigerant to the system. This can often fix the problem and restore proper function to the evaporator coil.

If you have identified a blockage or restriction in the refrigerant lines, you will need to clear it in order to fix the problem. This may involve cleaning or repairing the lines. It is important to make sure that the lines are properly sealed and functioning correctly in order to ensure proper flow of refrigerant through the system.

If the thermostatic expansion valve (TXV) is faulty, you will need to replace it in order to fix the problem. This is a more complex repair that should be carried out by a trained HVAC technician.

Finally, if the air filter is clogged, simply replacing it can often fix the problem. Be sure to check and replace the air filter regularly in order to prevent issues with the evaporator coil.

By following these steps, you can fix the problem of only the bottom half of the evaporator coil being cold and restore proper function to your air conditioning system.

Tips for Troubleshooting and Fixing the Problem

Here are a few additional tips for troubleshooting and fixing the problem of only the bottom half of the evaporator coil being cold:

Check the Indoor Air Handler

In addition to the evaporator coil, the indoor air handler is another important component of the air conditioning system. If the air handler is not functioning properly, it can affect the performance of the evaporator coil. Be sure to check the air handler and make sure it is functioning properly.

Check the Outdoor Condenser Unit

The outdoor condenser unit is also a crucial component of the air conditioning system. If the condenser is not functioning properly, it can impact the performance of the evaporator coil. Check the condenser unit and make sure it is functioning properly.

Check the Ductwork

If there are issues with the ductwork, it can affect the performance of the evaporator coil. Check the ducts for any blockages, leaks, or damage, and repair or replace as needed.

Clean the Evaporator Coil

If the evaporator coil is dirty or covered in debris, it can affect its performance. Be sure to clean the evaporator coil regularly to keep it in good working condition.

Check the Thermostat

The thermostat is responsible for controlling the temperature in your home or business. If the thermostat is not functioning properly, it can affect the performance of the evaporator coil. Be sure to check the thermostat and make sure it is working correctly.

By following these tips, you can help to ensure that your air conditioning system is functioning properly and keeping your home or business comfortable.

Closing Thoughts

If you are experiencing the problem of only the bottom half of the evaporator coil being cold, there are a few potential causes that you should consider. These include low refrigerant levels, restricted refrigerant flow, a faulty thermostatic expansion valve (TXV), and a clogged air filter.

By properly diagnosing the problem and taking the appropriate steps to fix it, you can restore proper function to your air conditioning system and ensure that it is working efficiently and effectively. Accessing the Evaporator coil isn’t that hard though.

It is also important to maintain your air conditioning system regularly in order to prevent issues like this from occurring. This can involve checking and replacing the air filter, as well as having a trained HVAC technician inspect and service the system on a regular basis.

By taking these steps, you can ensure that your air conditioning system is working properly and keeping your home or business comfortable.