One requirement for lil' yeti's makeover was fresh air. The Scamp originally had a ceiling vent. It was actually pretty neat technology in some ways. I just wasn't satisfied with how it was installed. Roof integrity was compromised by the old vent. The roof had actually sunk enough around the old vent to leak water inside when it rained. Unacceptable.
I removed the old vent in 2015 while summering in the precipitous White Mountains of NH. The roof hole was patched over. During the patch the ceiling was propped up and reinforced with extra fiberglass inside to correct and maintain proper shell geometry. Leak begone, permanently!
The resulting roofline was so clean and smooth. To maintain the streamline roof I considered a wall or window mounted fan. But eventually I decided to compromise and install a traditional power vent on the roof. But which one? My first Scamp had a Fantastic Fan, which was a fine product. But I much preferred the Maxx Fan that I installed in my third Scamp. (Lil' yeti's my sixth Scamp. In thirteen years. Not that I'm keeping track.)
Since 2007 the Maxx Fan product evolved some fancy new features. The full blown model now sports remote control, power open/close, digital thermostat, and 10 fan speeds. Sheesh! I was fine with the tried and true, old school knobs and switches they originally used.
I still had a purchasing decision to make.
Their basic model nixed three features that I didn't want anyway: thermostat, remote control, and power open/close. A friendly engineer at AirXcel (manufacturer) confirmed that the basic model's 4 speeds were a good subset from the fancy 10-speed model.
Cool. The only optional feature missing from the basic model that I valued was the switch to reverse flow between intake and exhaust mode. Fortunately, reversing the direction of a 12VDC motor is a simple matter. First, intercept the motor connection. It's just two wires for positive and negative voltage.
Then, insert a DPDT switch to reverse the polarity. No rocket surgery.
Full disclosure. An embarrassing number of months elapsed between my reverse switch mod and installation. In part because I needed an appropriate place to work. With favorable weather. When those planets aligned, I got around to bench testing, which revealed a problem. It kept blowing fuses. Even with the motor disconnected! The driver circuit board was defective. AirXcel was great about shipping me a replacement board. But they sent the wrong part. Mistakes happen. They made it right in the end. So it was finally time to install.
I like to work a bit smarter each time I do something. This time it was cutting a hole in the roof. The fiberglass shell was only about 1/4" thick. I decided to add a half inch plywood filler on the inside under the garnish trim. After marking the 14" rough opening on the ceiling I drilled pilot holes in each corner to transfer marks through the roof. The shim board was cut the same width as the garnish trim. Then aligned inside and wedged against the ceiling with a 2x4 prop.
From the roof I connected the dots and cut through to the plywood. For cutting I used an oscillating tool with carbide blade. I kept misting the cut area with water as I went. That produced a pasty mess which was easily wiped up. Moreover, no pesky fiberglass dust! With the roof section removed the plywood inside was already grooved by the cuts to match the opening. Nice.
The rest of the install was fairly straightforward. So I'll spare this post from those details and just skip to the end result. With the lid closed the roof's still fairly streamline for travel.
With the vent open the lid's overhang makes it fairly rainproof. Sweet!
Inside, the plywood shim still needs paint. (Like the rest of lil' yeti's interior, and exterior for that matter.)
I didn't bother labeling the direction switch. Instead, I tried to make it intuitive. For intake, flip it inwards (towards the center). For exhaust, flip it outwards.
How's it working? Great. We just returned from a couple nights in Death Valley NP. Since Furnace Creek CG was full (reservations!) we camped at Texas Spring. Can you see lil' yeti in this pic?
Generators aren't allowed at Texas Spring CG so it was a good boondocking field test. The fan worked great. Finally being able to properly exhaust cooking fumes was really nice. Another value added mod. Check.
