When is it time to flush your air conditioning condensers? There are a lot of different beliefs. I’ve seen some engineers have it done once a year, some when they get back to Ft. Lauderdale and others when the air conditioning system doesn’t work anymore due to high pressure.
Of course there are many pieces of equipment working together to perform the cooling process, but the condenser of an air conditioning system is the part responsible for removing heat during the cooling process. For marine purposes, the condenser is water cooled. Generally a pump pulls in sea water and circulates the water through the condenser one time and is discharged overboard getting rid of the heat from the interior of the vessel where it is not wanted. When the condenser becomes dirty, refrigerant pressures rise because of the lack of thermal contact and heat removal becomes more difficult. Other factors such as dirty sea water strainers and worn sea water pumps can attribute to high refrigerant pressures as well.
Safety circuits are usually installed to shut down the air conditioning system when the refrigerant pressure becomes too high. If the pressure was allowed to increase without shutting down the system for protection, expensive components would fail permanently. A system operating at higher pressures without reaching the safety shut down can also have affects on the life of components.
I recommend cleaning a condenser when the pressure begins to rise steadily due to a dirty condenser. An increased discharge pressure of 25 psi is enough to justify. The 25 psi increase is enough to affect system performance and increase amperage draw. Pressures allowed to go higher than 25 psi can decrease the life expectancy of equipment.
Many air conditioning systems have permanent pressure gauges or pressure transducers to relays the refrigerant pressure to a display. System without a resource for reading pressures will be required to check with a manifold gauge set. If your vessel does not have a permanent display read out, have the system pressures checked every six months.
Condenser cleaning is performed by a mechanical or chemical process depending on the type of equipment. Most often a chemical process is chosen. When using a chemical, the vessel should ensure an environmentally safe product is used. Stay away from muriatic and sulfuric acids as they will be harmful to sea life, personnel and equipment.
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