1. Your model is a 13.5 btu
2. IF you have a slide out and you are at 25 foot, the 13.5 will be marginal to cool that RV in hot temps above 90 degrees. Even if ducted
3. Curious, WHERE did you get the idea that the Delta was 40 degrees?????? It has always been 18 to 23 degrees.
4. "If the air moves across the coils, slower, it'll cool more than if the air moves faster. I can't believe they designed the evaporator to move the air across it slower though. That makes no sense."
The slower the air moves thru the evaporator the MORE cold the air can absorb. That is why running on LO COOL can cause a freeze up. The air moves slow and does not remove the acumillated cold on the Evaporator. Your model has just 1 fan motor and has 2 selections for Fan--HI and LOW.
5. The simple answer is your AC is not large enough to do the job. You need a 15k. Doug
