[SargeW]

Shoot, I cut a 3' hole in the side of a brand new Tiffin Phaeton in 2013 to put in a outside TV that the dealer didn't order. Did it in the camp area of the service center in Red Bay Alabama.

I plan to draw out a 4" circle where I suspect I will need the vent to be on the inside wall. Then I will drill around the 4" circle with a 1/8 drill bit about every 1/2". If I don't hit anything solid (other than the foam inside the wall panel) I wii follow it up with a 4" hole saw. Once the pilot bit pops through I will go around the outside and drill from the outside in.

It's rocket science, but 30 seconds from Keystone to tell me if there was a stud in the area would have been nice.

Unvented dryers or Combo units are a huge waste IMHO. WAY to long to dry anything.