Bathroom Fan Addition - 2021 T@B 320S Boondock

SLJ

My bathroom fan addition is done in my 2021 320S Boondock. Installed the 6" MaxxFan Dome fan.
Held my breath as I used a 6 1/4" hole saw. Drilling a large hole in the side is not for the weak hearted... 
Hardest part was boring a hole for running power horizontally inside the Azdel wall using a heavy solid copper ground wire. Went from the radio antenna cutout going just under the factory vent. Grabbed 12 volts under the bench for it. Mounted using supplied screws and Dicor non-leveling lap sealant.

Denny16

Looks nice…
cheers

LBW

"Drilling a large hole in the side is not for the weak hearted." You aren't just kidding!  It looks great!

Tabnero

I sure agree that it should have a fan, but not sure I would have been willing to do this to get it

VictoriaP

Tabnero said:

I sure agree that it should have a fan, but not sure I would have been willing to do this to get it

There’s a Dome Plus version which includes an LED light. I’ve thought about asking my dealer to replace the light fixture with that combo. Still requires a hole being cut, but I expect it’d take much less wire reconfig.

SLJ

VictoriaP said:

There’s a Dome Plus version which includes an LED light. I’ve thought about asking my dealer to replace the light fixture with that combo. Still requires a hole being cut, but I expect it’d take much less wire reconfig.

My goal was no more holes in the roof. Since it's not flat, an additional fan over the bathroom could lead to leaks especially since that area gets hit with high wind and driving rain when towing. I found the flat side to be an easier location to get a good seal and easily check and maintain the sealant.

Denny16

Never had water coming in through the shower area fan on our TaB400.
But, I can understand not wanting to cut a hole in the roof.
Cheers

Maxcamp

Thank you, SLJ!  What a great improvement and terrific writeup on your website.

Implemented this mod and extremely pleased with the result.  Running overhead fan to draw exterior air in, and running this side bath fan to exhaust, there is zero water vapor on the camper ceiling or walls, and little vapor on the bath ceiling or door behind our magnetic affixed curtain.
Final exterior pics missing from camera.

I tested the fan mechanically and electrically prior to install.
Mounted the handle vertically, with the handle slide release button upwards to operate with thumb.
The slide only locks on one side so uncertain there is a good air seal.  However we had heavy rain on two long drives and the interior stayed arid.

Although I did a test cut in plywood first, the cheapo 6-1/8" hole saw from Amazon had considerable runout (wobbled about the pilot bit.)  I would not recommend it as it created a slightly ovoid hole which I spray foamed.  Test yours before using.  Easy enough to swing a trim router to make a masonite template, and use a collar or guide bit.

Mechanical:
1. Laid out opening, drilled undersize pilot hole through wall.
2. Hole-saw 6-1/8" exterior fiberglass face first as it will track better.
3. Complete hole-saw from interior.  The soft foam will not allow the hole saw to 'track' well.  I ran it in reverse.
4. Took a minute for my heart rate to go down.
5. The furnished PVC wall sleeve is extremely flexible.  I firmed it up with a length of tightly rolled sill-seal inside, and easily cut on the chop saw.  Did a half inch test length first to ensure I'd get a clean cut.
6. I already had a can of spray foam adhesive for polyiso insulation, and coated the outside of the sleeve with this to aid it's seal to the foam cutout and minimize water vapor intrusion.
7. Test fit fan and ensure it opens and closes 
8. Mounted outside fan, bedded in Geocell Proflex RV sealant and caulked. 
8. I used no.10 x 1/2" pan head s.s. sheetmetal screws in every hole, not the few thin screws supplied with the fan.  Predrill and very gently hand tighten in the Adzel face.
9. Mounted outside escutcheon, bedded in Geocell, caulked, and similarly screwed.
10.  After final electrical and testing, installed inside escutcheon bedded in Geocell and caulked inside ring.
Also ran some more caulk on bathroom joints.

My 2021 trailer bath wall consists of:
0.13" outer Adzel or fiberglass face, appears to be two members with a paper or fiber center scrim.
0.13" glued backing to fiberglass, appears to be softer grey material.
1.0" foam having zero screw holding capacity
0.13" inside fiberglass/Adzel face, with bathroom vinyl wallpaper.

Electrical: 
I also fished the power from the fan opening to the camper antenna access hold sited within the microwave cabinet.
1. Unscrewed numerous monitors on the sleeping quarters wall shared with bath, that interfered with pulling the microwave.
2. Unplug, unscrew, and pull out face-screwed microwave.  On my camper it pulls straight out without leeway to angle away from the (former TV) wall.
3.  Remove the access panel inside micro cabinet that provides access to TV wall.
4.  I used a piece of electrician's metal fish tape to penetrate the outside wall along its length.   The bath stack vent riser interferes with the obvious route.  Unsuccessful working from inside cabinet towards new hole; ultimately worked back from hole and just caught the micro cabinet access area.
5. Pulled through pair of #16 wires.  The fan uses #18 or smaller.
6. I distrust crimp splices in a bouncing camper.  Twist, solder, and heat shrink insulate.  Made a small notch in foam wall sandwich cutout to next the splice, and dabbed with a finger full of expanding spray foam.
7. Home run fished down (former TV) wall- another challenge- to the former TV/Radio 12v circuit.
8. Tested operation and jounced trailer a few times to be certain.
9. Closed everything up.

SLJ

Looks great. Nice job. I drilled mine from the outside. Hole saw was solid and gave me a nice clean hole all the way through on the first try. I also used the same hole saw for adding a hatch in the bathroom for accessing the Glycol tank.

Maxcamp

Forgot to mention did your marine access hatch for glycol as well in anticipation of glycol flush. Great idea.
Thanks for the informative posts on website.  Well worth it for folks to take a look.

SolidCamper

Thank you Maxcamp8 and SLJ for your extremely well-detailed posts and construction sequence regarding the MaxxAir bathroom fan installation. From your descriptions of fishing wires through the insulation of the outside wall, there is no mention of having to penetrate or bypass any vertical framing members. Am I to understand that the exterior sidewalls do not have any full-height vertical aluminum tubing members ?. (I actually consulted the structural plans posted by Muttonchops and didn’t see vertical tubing (ie studs) but still wanted confirmation on that.  Thanks. 

Maxcamp

Adzel panel, no stud encountered. 

SLJ

SolidCamper said:

Am I to understand that the exterior sidewalls do not have any full-height vertical aluminum tubing members ?. (I actually consulted the structural plans posted by Muttonchops and didn’t see vertical tubing (ie studs) but still wanted confirmation on that.  Thanks. 

I used an electronic stud finder to check first, then sent a photo to NuCamp showing my drilling location and asked if it had any studs or wiring in that location. They confirmed my 2021 was clear in that exact location.

SolidCamper

Thanks to both of you for your help in that dept. Not having to deal with the tubing should make it easier. 

Maxcamp8 implied that SLJ had posted details of his installation on his website. Could either of you provide me a link to that website. Thanks. 

SLJ

SolidCamper said:

Thanks to both of you for your help in that dept. Not having to deal with the tubing should make it easier. 

Maxcamp8 implied that SLJ had posted details of his installation on his website. Could either of you provide me a link to that website. Thanks. 

Here's the link to the mods I've done so far: https://teardropsandtinycampers.com/sj-mods.htm

Clipper_One

@SLJ
Excellent idea for gaining access to the glycol holding tank in the wet-bath, I was wondering, do you have the dimensions you used for positioning the 6” access panel? Or did you you guess?

If you wouldn’t mind could you please let me know how far is the round access panel edge from the right side wall, and how far from the top edge of the sink or bottom of toilet, I don’t want to guess and damaged the panel. Since you drilled yours from the outside you had known where to place the hole saw. 

I really like your write up it is very well described and it looks amazing.
Thanks in advanced.
Clipper_One
Carl

SLJ

This is the location of the center of the access port on my 2021 T@B 320. Gives me enough room for the six screws and nuts without hitting the plywood on the right and bottom of the cabinet behind the panel. I can't guarantee the wood backing on others is the exact same distance but this allows me to remove the whole panel with the port attached and locates the bottom of the port at the top of my tank.