Dual AC units

The bigger 15K unit is responsible for cooling a larger area with the 13.5K AC in assist mode for cooling the bedroom area on hotter days. If you order your new TT you can get whatever sizes you prefer, I have even seen TTs where both AC units are the larger 15K units. Enjoy your new TT!!!

If you are not summer camping in the south you probably don't need it. I camp in the summer in Florida and only have a 13.5k which works fine with a little shade from the trees and mine is not insulated very well.

Other than costing a small amount more - I can't see any other negatives to a 15K and a 13.5K.

With a properly ducted dual AC setup - the bedroom AC can keep the main living area comfortable when eating or watching TV with a minimum of noise in all but the worst summer conditions.

The 15K unit will be better at dealing with warm weather humidity.

But it's your choice.

Personally, I always go with whatever gives me the most options for use. I try to not limit my options in a RV/TT.

dual AC's will require a 50amp setup.

If I had the option I would have them install two 15K units in a 30'.

There is no technical reason not to have two 13.5k units. The only downside is the lesser cooling ability of the smaller rear unit. We have a 15k in the living area and a 13.5k in the bedroom in our 35' 5er. After a long day of travel when the temps are 100+ it takes both units 2-3 hours to get the inside temp really comfortble. After that the 15k will keep it cool with the 13.5k off. Not sure a 13.5k would. Since you do not camp often in the hot summer, two 13.5k units probably would work fine for you.

Manufacturer probably just does not want buyers coming back and saying the smaller ACs do not cool well.

BB_TX wrote:
There is no technical reason not to have two 13.5k units. The only downside is the lesser cooling ability of the smaller rear unit. We have a 15k in the living area and a 13.5k in the bedroom in our 35' 5er. After a long day of travel when the temps are 100+ it takes both units 2-3 hours to get the inside temp really comfortble. After that the 15k will keep it cool with the 13.5k off. Not sure a 13.5k would. Since you do not camp often in the hot summer, two 13.5k units probably would work fine for you.

Manufacturer probably just does not want buyers coming back and saying the smaller ACs do not cool well.

I too have this set up in my 5er. We run the two units to get the heat out and then only run the main 15k unit at night. If the temps start to get up in the daytime we run both and the door to the bedroom wide open.
I have used this set up for 3 summers in NC/SC now. I used both Ac during our Thanksgiving trip to take the heat down in the camper several days when the sun shined bright. and then ran the 15k main unit at night once. then before the week was over I had the heat on wide open with my Duraflame Amish style heater going too. SC beach weather???
IT boils down to what ever makes you comfortable. BUT a lot of the campers even if you order it, have retail packages and the 15K main unit might not be allowed to be removed or could cost you in resale value or just cost more because you messed up the dealer/ builder package.
JMHO
randy

In my opinion, and take that for what's it worth, it depends on how good the AC unit is. My brother has a Coleman Mach unit on his 28 foot 5th wheel. It's suppose to be a 15k unit but, it is designed so poorly that it barely keeps his RV cool on a 90 degree day.

Thanks for all the input. What I didn't realize is that both units share ductwork so actually not cooling separate areas. We'll probably go with the 15K main and 13.5 in BR so I can still run that one off of my generator if needed.

I'd verify that with the manufacturer if you haven't already. Some trailers come with a non-ducted second A/C.