never enough btu's
I installed the 16K btu by mermaid last summer. You can never get enough btu's in a hot climate. I decided to do it when I learned that the price and size differential was nominal between the 12k and 16k units. The c30 is not insulated real well, it still takes a lot of work for the unit to cool a hot boat in the summer. In a home you don't want too big a unit since it will cool the house too fast and not adequately reduce the humidity. On a boat, with poor insulation, the ac will still blow for hours to cool it down and will greatly reduce the humidity, even with the big unit. My suggestion is get the most btu's you can afford and have the space to accomodate.