Air Cooler Unit

The “Air Cooler Unit” course is focused on the design, operation and maintenance of onboard air-conditioning / air-cooling units. These compact systems are based on the same principles as refrigeration plants and typically combine a refrigeration compressor, condenser, filter-drier, thermostatic expansion valve, evaporator and the complete control and monitoring system in one unit. Such units are often installed in the ECR, main switchboard room, cargo control or automation spaces and other critical locations where a stable temperature is required for reliable operation of electrical and automation equipment. Failure of an Air Cooler Unit can cause serious operational difficulties due to overheating and can also create uncomfortable working conditions for the crew. A marine engineer should therefore understand the operating principle of the system and be able to maintain and repair it efficiently.
This course will help you approach the operation and maintenance of modern Air Cooling Units with a clear understanding of the system rather than uncertainty.

The course is suitable both for engineers at the beginning of their careers and for experienced seafarers who want to strengthen their knowledge of onboard air-conditioning systems. It explains the purpose and operating principle of each main component and builds confidence in practical maintenance work.

This part focuses on practical work with air-conditioning systems. Using real onboard footage, we assemble a refrigerant recovery setup, connect the hoses and examine the correct procedure for recovering refrigerant from the system into a cylinder. The operation of a Recovery Unit is explained step by step with practical comments and recommendations.
We also discuss common operational problems such as frosting of the evaporator and compressor suction side. This lesson combines theory and practical shipboard experience and is useful for both junior and experienced marine engineers.

This part explains how to test the system for leaks both under pressure using an inert gas (nitrogen) and under vacuum. We discuss the required vacuum level and the subsequent steps needed to prepare the system for refrigerant charging. The correct connection of the refrigerant cylinder to the condenser through the compressor and a four-way manifold gauge set is shown in detail. Refrigeration scales are then used to charge the system while monitoring the exact refrigerant weight.

This part covers the practical procedure for changing from one refrigerant cylinder to another while charging an air-conditioning unit. Based on real onboard footage, we discuss the correct sequence of actions and the details that require attention. The amount of refrigerant charged into the system is controlled by weight and the process is stopped once the required quantity has been reached. The design and use of a four-way manifold gauge set are reviewed for different operations. We also examine the thermostatic expansion valve (TXV), including its operating principle and adjustment when changing refrigerant type. The TXV is disassembled to demonstrate spring adjustment and its effect on superheat.
This lesson completes the course package and consolidates the previously covered principles of refrigeration-system operation.