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Buying a Marine Air Conditioning System – Considerations for Boat Owners

Buying a boat for the first, second, third or tenth time is always an adventure and outfitting it with the latest hi-tech gear is all part of the fun. This should also be the case when selecting your on-board air conditioning (A/C) system. To make choosing the right system for you a care-free experience, just ask yourself these questions:
Do I need one?

It’s a common misconception that air conditioners simply cool the air, but in fact, there’s a lot more to it. Quality A/C systems can also ensure a comfortable on-board environment by providing year-round heating and cooling capabilities, removing moisture from the air, preventing dampness, rot and mold and controlling humidity, not just in the living spaces but other parts of the yacht too. So, if the temperature in the location you normally boat in is not particularly warm, there are still other factors to consider such as high humidity of air due to close proximity with water. 

What kind of system is best for my boat?

When determining which system to buy, the size of your yacht is very important. Marine air conditioning systems use water cooling methods rather than air, which is logical considering the vast amount of water provided by the sea, and this allows us to build a more compact unit to suit space limitations on-board. For smaller boats up to 40ft, self-contained systems are the best choice due to the lower cost and easy DIY installation, which is usually under a bunk or settee. Larger yachts up to 80ft should consider split-gas air conditioning systems, which have the condensing unit in the engine room and air handler in the living space. Chilled water systems are the ideal option for larger boats and superyachts and can be tailored to specific needs by specialist manufacturers.

Which one should I get?

The cheapest option is not necessarily the best and you should remember that buying an air conditioning system is not something that should happen often. High-quality, innovative engineering is a must as is a manufacturer’s history in producing rugged systems that can withstand the harsh marine environments and work efficiently with the boat’s power source. Check out the brand’s reputation and whether it has a service networkfor instance – you never know when you might need it.


What maintenance is required?

If the air conditioning unit is properly manufactured to a high standard, then only minimal maintenance will be required to ensure maximum performance and longevity of the system. For boat owners with self-contained systems, some DIY summer and winter preparation is recommended. This includes checking areas such as the seawater strainer, thru hull and heat exchanger for any debris pulled in with the seawater as well as the condensate pan to make certain it is draining properly. Alsocheck the system’s hoses, coils and other piping for leaks and check your return air filters to make certain they are clean and free of debris. In winter, you should run a little biodegradable antifreeze through the unit. Maintaining a split-gas system takes a little extra effort because different components are located in different parts of the boat but the principles remain the same, just ensure there are also no refrigerant leaks. Chilled water systems will require regular service checks by on-board or local service engineers due to the complexity of the system.

What about electrical requirements?

Most marine A/Cs run on alternating current (AC) power and come in different power configurations, but the electrical consumption depends on the size of the air conditioner. Specification sheets will show the running current information for the unit and will also advise how to select the right circuit breaker, but make sure a generator, inverter or shore cord can handle the inrush current of the compressor when an air conditioner starts.


By Doug Curtis, Vice President of Marketing, Dometic Marine.

Dometic Marine is the world’s leading supplier of marine air conditioning systems. The company’s expert engineers work closely with boat owners and offer an extensive range of problem-solving products. For further information, visit

Print | posted on Friday, September 23, 2011 4:21 PM