Maintenance

Engineer in charge of the watch has to maintain the A/C system in good condition by setting and monitoring the operating values. Sensors provided for fault-free operation makes it possible for the engineer to detect the problem before the malfunction occur. They must be calibrated, tested and well adjusted. Observing compressor oil and refrigerant levels as well as water or air in the coolant, operating pressures and temperatures and the electric power properties are some of them. Due to the importance, all A/C system components all sensors, actuators, indicators and starters must be provided on automation and need to be well maintained.

One of the most important issues of the air conditioning system is the frequent cleaning of oil, water, air and moisture-retaining filters that affect quality, energy and efficiency. If the filter permeability falls below a certain value, it will cause an alarm. Responsible personnel should wash or replace these filters. If this maintenance is not done, the air passage through the coils in the AHU will decrease, thus the heat transfer. In this case, the entire system will have to work continuously in order for the air-conditioned environment to reach the desired values. This will lead to negativities in quality, system life and energy consumption. Air filtration is the first step in the air conditioning process. Different filters such as fiber, cloth bag, oily, dry, washable or disposable are used in ventilation and air conditioning devices. Fiber type filters are generally used in commercial ships.

The permeability of the filters is controlled by pressure sensors and differential pressure switches located at the inlet and outlet of the filter cassette. When the filter permeability drops below a certain value as a pressure difference, the automation system gives an alarm. Responsible personnel should wash or replace these filters. The amount of air passing through the unmaintained air filter, and therefore through the heating, cooling, dehumidification and re-humidification coils, will decrease, air conditioning quality will reduce, and energy consumption will increase. Marine Engineer is responsible to operate the air-conditioning systems with proper knowledge.

Following procedure in sequence will help the Marine Engineers for cleaning the air filters in order not to spend excessive time and maintenance material. The works listed below are general points to be managed by the Marine Engineers. There may be few differences related to the air condition and ventilation systems as well as company instructions on maintenance.

·         Acknowledge the clogged filter alarms,

·         Inform relevants that you are going to stop the AHU for one (1) hour.

·         Check if all air property sensors, damper actuators, valve motors, valves, air fans and electric motors, door locks and gauges are in good condition,

·         Hang up the warning sings to the valves area and to the starter panel of the related AHU,

·         Stop the AHU from starter panel,

·         Close the supply and return valves if not automatically done,

·         Close all dampers if not automatically done,

·         Open air filter section door,

·         Use the hook tong to pull out the filter-cassette,

·         Inspect the heating coil surface if covered with dust. If so, clean the coil surface.

·         Check if the heating coil fins are deformed. If so, use fin comb to correct,

·         Take the air filters out of the cassette, replace with the new one or wash according to the filter maintenance manual,

·         Check if the sealing rubber gasket is in place. If damaged, repair or replace it,

·         Install the dried filter or the new one in right direction as shown in the manual,

·         Be sure that filter cassette installed in house properly,

·         Close the filter cassette cabin door,

·         Undo all jobs from item 6 to 1 in order,

·         Reset alarms when you see it working normally,

·         Activate the system by informing the relevant parties.