27rbds and 28rbds second ac

[RodneynDawnT]

I have a 2016 Winnebago Instinct 28rbds, very similar to the 27rbds - the most noticeable difference being the front cap. Anyway, last summer I had the stock 15k Dometic Duo Therm replaced with a 15k Atwood Air Command with heat pump (these are now marketed as Dometic Air Commands). I kept the duo therm to possibly add above the bedroom later. I finally got around to having that done.

A few issues with adding a second unit to the 28rbds are that the roof above the bedroom roof is at an angle, the distance between the bedroom roof vent and wall is about an inch to short for the inside cover to fit (this may or may not be an issue with the 27rbds, depending on installed wall configuration - I’ve seen more than one setup), and while my 28rbds has 50amp power, the vent cutout was not prewired.

Fortunately, the duo therm literature says the it can be installed up to 15 degrees left, right, front or rear. This varies by manufacturer and ac model.

The wire was run and is completely hidden. It was run from the breaker box through the ceiling past the kitchen skylight then through the ductwork to the bedroom vent and into to vent cutout.

I used an oscillating tool to cut about an inch off of the inside ac cover so that it butts against the bedroom/den wall. I installed some weatherstripping material where they meet.

I’ll attach some pictures to better explain.

I still need to do a couple of things. I need to trim the vent from the main ac so the the cover will be flush there and add a heat strip before winter. We’re going on a trip in the morning and will get to try it out more than just in the yard.

[RodneynDawnT]

I wanted to add a couple of things. The Dometic duo therm up front is what they call the “Brisk II”. It worked great for our Labor Day trip last weekend, although I only turned it on for about an hour or so when we set up and again when we were shutting down. The trip was 4-500 miles.

If anyone is looking to add a second unit but have only 30 amp service, there are some really good videos on YouTube for neatly having a second power cord dedicated to the second unit powered from a 20 amp outlet. Most campgrounds tend to have a 50, 30 and 20amp outlet in the same box.

[RodneynDawnT]

I’ve been wanting to customize the second a/c a bit for awhile. I did that this weekend. I didn’t like the vents on it - not very directional. I added a dual directional vent - major improvement. I been wanting to run a duct through the wall into the living area. I did that with another dual directional vent (very hidden). The stick on gasket I used kept coming unstuck so I replaced it with a bulb gasket that snaps on like you might find on the trunk of a car. And I finally trimmed the bedroom vent from the main ac to allow the bedroom ac inside cover to fit snug against the ceiling.

[Fasttimes]

Looks great. We have a 27RBDS and I could definitely see the need for the 2nd air. I guess this is something to think about in the future.