I too was very skeptical about a single 13500BTU AC cooling even the small interior of our Gemini. Sure enough it didn't when temps were over 90 and the sun was on it. I opted to install a second AC, and went with a matching low profile Dometic that is also a heat pump, with a second matching Dometic digital thermostat. Looking at it, from inside or out, you would never know it didn't come from the factory that way.
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