MTSea marine refrigeration and air conditioning


Mark Critchley and Tania Nicholls look at the different aspects of a successful maintenance regime for HVAC and refrigeration systems

Imagine one of these scenarios, the owner is on board or the yacht is full of charter guests, the fridges and freezers are packed to the brim and they have just stopped working, or maybe the AC in the boss’s cabin has just stopped. No yacht engineer or captain really wants to deal with any of these situations. The ramifications of these predicaments are at best an inconvenience. Beyond that can be unexpected expenses due to ruined food or damaged charter reputations. The solution – be on top of the yacht’s maintenance needs.

Maintenance regimes
These can be divided into four different types which all have their time and place.

  • Preventative maintenance – carrying out checks and service as dictated by the manufacturer plus attending to systems based on historical data
  • Condition based maintenance – process of monitoring and inspecting systems to a planned schedule and the service, repair and or replacement of components in poor condition
  • Risk management maintenance – the maintenance of a system and its components, the carriage of tools and spares based on the judgement of what is most likely to fail
  • Failure maintenance – the repair of a system or components when they fail

Preventative maintenance
First and foremost, read the manufacturer’s instruction book, it gives guidance on preventative maintenance from daily checks to annual inspections. Be methodical and keep a logbook for each system, record problems, works done and data such as pressure readings, get to know what is normal for your system.

Condition based maintenance
There are a number of pre-season refrigeration and air conditioning condition-based checks. Check the pumps are working and service parts including impeller are inspected and replaced where needed. Check refrigerant pressures in the seawater condensers, this is your best tell regards marine growth. The easiest way to do this is to have gauges installed and regularly record the readings. Systems that don’t have gauges should be checked by a refrigeration company either annually or bi-annually depending on activity and use of the yacht. The connections on the electrics of the system should be checked for loose connections and damage including saltwater and heat damage.

MTSea marine refrigeration and air conditioning
Marine growth in seawater pipework, Worn seawater pump impeller

Risk management maintenance
Even with good preventative and condition based maintenance procedures, it is quite likely you will get some failures. This is where risk management maintenance comes in. Obviously, it is not practical to keep a complete store of all the yacht’s parts and specialist tools onboard instead, a judgement call needs to be made. The main questions are, what is most likely to go wrong, and what critical parts may not easily and quickly be sourced? Have a knowledgeable and trusted dealer and build your support networks. Purposefully develop good relationships with refrigeration specialists independent of your current yacht, these are people who will answer the phone when you call, regardless of day of the week and your location.

Failure-based maintenance
Onboard breakdowns are inevitable but using failure-based maintenance as a way of maintaining a yacht will leave everyone vulnerable and in the long run is unlikely to save money. When considering priorities for maintenance it might be tempting to dismiss air conditioning and refrigeration as non-essential systems, but this is not so. Air conditioning is an integral component of the ventilation system on a yacht and is therefore safety critical in areas that are not naturally ventilated. Fridges and freezers have to be reliable, or they can become a significant hazard.

And don’t just take our word for it google says the benefits of effective maintenance are:

  • Lengthen asset lifespan
  • Lower risk of breakdowns
  • Increase efficiency
  • Decrease unplanned downtime
  • Save money

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