ROOF AIR CONDITIONER

Sometimes bigger isn't better. A lot has to do with humidity.
No matter what size ac you have, in a Class B 15 to 20 degrees below ambient temps is about the best you can do.
Read this.

I have one of those 11000 btu Penquins and it is barely capable of cooling the rv at 100 degrees. 15000 would be better. Depends on how much space you have inside your rv and if airconditioner is working at max efficiency.

BTU size would depend on the model and year of the RT.

Most/all Chevy based Roadtreks (from 2002 up) used a Dometic CoolCat heat pump which I believe has 12,000 BTU's of cooling

My '95 RT has 5000 BTU Fedders.

If you want some kind of template, my Dodge is a 7100 BTU.

Which RT model are you asking about

I am just down the road in Windsor lol

Maybe if you ask roadtrek they might help.
john 'I am Canadian'

Could someone please advise if a 5000 btu air conditioner
is large enough for a roadtrek. thanks