While I don't have the same RV I found that,like mgirardo, the way the vents are located it gives uneven heat throughout the RV.
I have 4, one in the dinette area one in the hall and very small bathroom and in the rear bedroom.
I found that the bathroom got very hot and I had to keep the door open to get even heat. The problem is that all the registers have no damper in them.
After I replaced the bathroom one with a register that has a damper and closing it about 80 percent I got more even heat throughout the RV and the bathroom is not over heated.
Works great and it is an easy job,I used
one of these to do the job.
They also come in
different colors and shapes