How To Determine If The Cooling Coil Is Leaking Or Blocked?

Visual Inspection

External Leakage Signs: Examine the exterior of the cooling coil and its connections. Look for any signs of water droplets, moisture, or water stains on the coil surface, pipes, or fittings. If there is refrigerant in the coil, you might also notice oil stains, as refrigerant often contains oil and a leak will carry the oil to the surface.

Corrosion and Rust: Check for corrosion or rust on the coil. These can be indications of water leakage, especially if the coil is made of metal. Rust spots or areas of corrosion may suggest that water has been in contact with the metal surface for an extended period, possibly due to a leak.

Blockage Indicators: Visually inspect the fins of the cooling coil. If they are covered with a thick layer of dirt, dust, or debris, it could indicate that air flow through the coil is restricted, which might be a sign of blockage. Additionally, look for any visible signs of damage or deformation to the coil that could cause blockages.

Pressure Tests

Hydraulic Pressure Test: For a water-cooled coil, a hydraulic pressure test can be conducted. Isolate the cooling coil from the rest of the system and fill it with water at a specific pressure higher than the normal operating pressure. Then, monitor the pressure gauge. If the pressure drops significantly over a certain period, it indicates a leak in the coil.

Refrigerant Pressure Test: In the case of a refrigerant cooling coil, use a pressure gauge to measure the refrigerant pressure. A significant deviation from the normal pressure range, especially a sudden drop in pressure, may suggest a refrigerant leak. If the pressure is abnormally high, it could be a sign of a blockage, as the refrigerant may not be able to flow freely.

Flow Tests

Water Flow Measurement: Install a flow meter in the water line connected to the cooling coil. Measure the water flow rate. If the flow rate is significantly lower than the designed or normal value, it could indicate a blockage in the coil. This could be due to scale buildup, debris, or other obstructions inside the coil.

Air Flow Tests: For air-cooled coils, use an anemometer to measure the air flow across the coil. Reduced air flow may suggest a blockage, such as dirt or debris clogging the fins or the air passage.

Temperature Tests

Surface Temperature: Use an infrared thermometer to measure the surface temperature of the cooling coil. If there are significant temperature variations across the coil surface, it could be a sign of a problem. For example, if some areas of the coil are much colder or warmer than others, it may indicate a blockage or a leak, as the heat transfer process is affected.

Inlet and Outlet Temperature Difference: Measure the temperature of the fluid (water or refrigerant) at the inlet and outlet of the cooling coil. A smaller than normal temperature difference may suggest a problem. If the coil is blocked, the fluid may not be able to exchange heat effectively, resulting in a smaller temperature change. If there is a leak, the cooling capacity may be reduced, also leading to a smaller temperature difference.

Operational Performance Checks

System Cooling Capacity: Observe the overall cooling performance of the system. If the system is not able to cool the target area or object to the desired temperature, it could be due to a leaking or blocked cooling coil. The cooling capacity of the system will be affected if the coil is not functioning properly.

Noise and Vibration: Listen for any unusual noises or vibrations coming from the cooling coil or the surrounding components. A hissing sound may indicate a refrigerant leak, while rattling or vibrating noises could be caused by blockages or other mechanical problems.