I'm looking for response from folks that have 22" TT or shorter units!. My 40' DP didn't cool very well in 100 degree days.. So I changed them (2ea) to 15000 units and it made all the difference in the world.
2006 WINNEBAGO ASPECT 29H Ford E450 Super Duty 2018 F150 Lariat Crew Cab, Coyote 5.0 L RWD
Are you using your trailer in Sedona AZ area? Around this time of the year I believe afternoon temps there typically hover around 95-100.
In our neck of the woods (south of Sedona), where temps are regularly 105-110 degrees (humidity less than 15%) , we've found a 13.5k unit (in a shorter ~20 ft. TT) will cool reasonably well (78-79 deg interior temps) if you cool the trailer down before the hot afternoon temps hit. If you attempt to cool down a hot trailer at 2pm with ambient temps already hovering around 105-110 you may be waiting a few hours (sometimes more) before you feel any sort of relief.
My 13-5 has kept my 20ft trailer at 68 degrees in 100 degree weather, direct sun.
Most of the time it's too powerful and cools the cabin before it can de-humidify it, at least with my sweaty self in there.
HOWEVER, this is in Michigan, where it's been 80%+ humidity for the past month. In bone dry south-west air, as I understand it, an air conditioner is going to struggle a lot more.
I have a 30' with one AC unit (13500). Recently in Tn it was 101 degrees. As long as the AC stayed on it would maintain the set temp of 74. Hope this helps.
2017 SportTrek 271 VRB 2016 F150 Eco boost with max tow package