What Size Generator Suits my A/C Needs?

By: Andrew Holland

It’s not unfamiliar for anyone working in the yachting industry to run into the question of what generator size is required on a particular boat. An answer will depend on a few variables, such as the boat’s size, where the boat will be spending most of its time, and whether there will be access to shore power. However, the most telling question a sailor can ask is how often air conditioning is needed.

In our client’s experiences, they often over-power their boats—meaning they will equip their boat with a generator more powerful than is actually required. This results in a more costly and unnecessary expense for an owner. But how can one determine which size is right?

The first question we ask clients is how many evenings per year they think they will need to run a generator for air conditioning while they are at anchor. The answer is often when clients are stuck in windless marinas where there isn’t the necessary airflow into the boat to cool it down that one resorts to turn the A/C on, not just anchoring in a place known to be hot and humid.

However, while dockside you’ll have the ability to plug your boat into shore power, so you will not be dependent on your generator. To bring your boat to a frigid chill, you may need as much as 15 amps of power, all depending on how large your boat is.

The best piece of advice we can give to those in the market to buy a boat is to get sufficient air conditioning to completely chill the boat dockside and get a smaller generator to run one or two of the air conditioning units for the rare days that are uncontrollably hot or humid at anchor.

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About Andrew Holland

Andrew Holland is the Sales and Marketing Manager of The Multihull Company and an avid catamaran enthusiast. After joining TMC in 2007 he began working closely with TMC President, Phillip Berman, learning the many facets of the catamaran industry. Having overseen the sale of over 800 catamarans around the world. He is able to take the most complex transaction and make it a breeze! Articles by Andrew Holland include:


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