[dieselguy]

I believe I’ve discovered a design flaw in the newer Montanas with the dropped frame. I’ve never been too impressed with the heating and cooling of my 2011 Montana. It’s also been the draftiest fiver I’ve owned. There’s a 1.5” thick aluminum framed wall that separates the main cargo bay from the kitchen level of the fiver. When I removed the white partition from the back of the convenience center as well as the pressed board wall from inside the cargo bay … I got a big surprise. There is a 1.5” gap between the main floor area and the partition wall. This gap allows air conditioned or heated air to fall into the belly and into the dead space between your frame and the lower aluminum skirting both of which are by no means well sealed. On a windy day this gap also allows air from the outer dead space and belly to blow up into your fiver to a certain degree depending on open windows or vents. There is also about a foot of wall missing right behind the convenience center. With the white panel behind the convenience center removed, you can look right at your hot water heater and furnace or on into the living area. Finally, there is about a 2.5” gap between the bottom of the bedroom floor and the top of the aluminum framed wall in-between the floor joists.
As seen in the photos, I added four 24” by 10.5” pieces of insulation in-between the main floor and the cargo partition wall. I then cut a 12.5” by 31.5” piece of plywood to cover the hole behind the convenience center. (notched out for water and drain lines) I also added blue foam insulation in-between the aluminum frame in the cargo area and the bedroom floor. I‘ve already noticed my draft is gone and with the cool nights lately, I’ve noticed the furnace doesn’t cycle as much. Time will tell this summer as to A/C improvement. One last note … since I had the wall removed, I cleaned up the installation of the electrical wiring, cable lines, and furnace vents as well as checked all water connections.