Emergency hatch Maxxair fan / skylight?

[kellin]

Hey everyone,

My Maxxair fan is arriving Friday and I have some decisions to make.

The only possible location for the fan is where my emergency hatch currently is. I wanted to get some opinions on what the best course of action is for installing fans into this space

As of now, I'm debating between A) maintaining the functionality of the hatch and building the fan into it - removing the hatch and replacing it with steel and building the fan into that - or C) replacing the hatch with something like Lexan and building the fan into it so I can get a bit of a skylight along with the fan.

I have some concerns about whether the Lexan would be able to support the fan. The functionality of the hatch is not really important to me since I have a ladder in the back of my bus. The emergency hatch measures roughly 22" x 22". Does anybody have input on this/able to share what worked for them in a similar scenario?

Thanks!

 

[DeMac]

Many here have done the same. I searched the site, read several threads and copied what had been done before me.

Check out the rest of the album here.
https://www.skoolie.net/forums/members/39257-albums2121.html
I detailed the specifics in the picture descriptions.

 

[kazetsukai]

I did skylights: https://www.skoolie.net/forums/f11/kazetsukais-build-22680-14.html#post395287


The amount of light that they bring in is incredible, enabling us to not have to turn on lights during the day (we removed the original windows). Also, since one is over the bed, we can enjoy stars, lightning, etc. The Maxx fan is going to be 14" ish, which will use up most of the space making a skylight surround not all that fruitful by comparison. I also don't see an advantage to keeping the hatch.


Can the Maxx fan really not go anywhere else? Have you considered somewhere not at the apex of the roof? I'm thinking of doing a retrofit, and the only places available to me are the sides of the roof- I'd have to work around the curve in one way or another.

 

[o1marc]

Option C, excellent idea. You'll be surprised how much light the 5" surround lets in. I need to trim the cover onto the unit with some wood.

 

[musigenesis]

I installed mine on the side of my roof by fabricating this projection:



which keeps it level above my shower stall (MaxxAir says to not use them over a shower but oh well). This projection might look complicated, but once you figure out the shape of that one side triangle the rest is just rectangles stitched together.

I think building the fan into the hatch is an interesting idea and not too difficult. Just cut a 14"x14" hole in the middle of the hatch and install (hatches are kind of a funky two-layer pressed plastic structure, so after cutting the hole you might need to reinforce around the edges in some fashion. I have cut a similar center hole in one of my hatches, although I'm going to cover it with Lexan rather than a fan. To form the edges of the hole, I'm going to pack XPS foam in between the two layers of the hatch and then cover this with Bondo.

 

[kellin]

I did skylights: https://www.skoolie.net/forums/f11/kazetsukais-build-22680-14.html#post395287


The amount of light that they bring in is incredible, enabling us to not have to turn on lights during the day (we removed the original windows). Also, since one is over the bed, we can enjoy stars, lightning, etc. The Maxx fan is going to be 14" ish, which will use up most of the space making a skylight surround not all that fruitful by comparison. I also don't see an advantage to keeping the hatch.


Can the Maxx fan really not go anywhere else? Have you considered somewhere not at the apex of the roof? I'm thinking of doing a retrofit, and the only places available to me are the sides of the roof- I'd have to work around the curve in one way or another.

Thanks for that info. I have a 23-foot short bus so unfortunately, that comes with limited roof space. My solar panels are in the front and stop a few inches short of the hatch - and the whole area behind the hatch is going to be where my deck is.

 

[kellin]

Option C, excellent idea. You'll be surprised how much light the 5" surround lets in. I need to trim the cover onto the unit with some wood.

That second picture is exactly what I had in mind! What type of material did you use for the skylight portion that the fan is mounted into and is it strong enough to hold the fan? I have seen around the forum that people used Lexan, but is there any particular kind of plexiglass that works best when it comes to fitting the curve of the roof and maintaining its strength? Thanks, everyone for the replies.

 

[o1marc]

That second picture is exactly what I had in mind! What type of material did you use for the skylight portion that the fan is mounted into and is it strong enough to hold the fan? I have seen around the forum that people used Lexan, but is there any particular kind of plexiglass that works best when it comes to fitting the curve of the roof and maintaining its strength? Thanks, everyone for the replies.

Plexi can crack and break, never use it. Lexan is the right product, acrylic, polycarbonate sheet. 1/8" is more than thick enough , the fan doesn't weigh much. I took out both hatches and replaced with Lexan, then cut the vent/fan into the rear one between the bunk beds. There's a seller on eBay that will have, or will cut to size what you need. So you don't have to buy a whole sheet. 26" fits the 24" hole.

 

[kellin]

Plexi can crack and break, never use it. Lexan is the right product, acrylic, polycarbonate sheet. 1/8" is more than thick enough , the fan doesn't weigh much. I took out both hatches and replaced with Lexan, then cut the vent/fan into the rear one between the bunk beds. There's a seller on eBay that will have, or will cut to size what you need. So you don't have to buy a whole sheet. 26" fits the 24" hole.

Perfect. Exactly the info I was looking for. Looks like I will go with the 1/8 inch dark grey tint. Couldn't find the 26" sheets but he has 32" x 32" that I can cut down to size. Thanks for your help!

 

[kellin]

Actually, upon doing some research - I've been seeing some debates on clear vs tinted Lexan. Thoughts on which would be better in this situation? I assumed tinted to block some of the heat from the sun.

 

[Mountain Gnome]

Actually, upon doing some research - I've been seeing some debates on clear vs tinted Lexan. Thoughts on which would be better in this situation? I assumed tinted to block some of the heat from the sun.

I'd get clear.


If I really though the sun would be a prob sometimes, I'd get a second sheet of cheapo tinted plexiglass (not Lexan) and have that ready to install on the inside in those circumstances.


My roof hatch is double-pained Lexan, all clear. The light it lets in is invaluable, and I even kept all my side windows.


My skylight also is hinged, and can open. I plan on making a fan assembly that will fit nicely in that hole, then I can crack the lid, and turn on the fan. So far, though, just opening the hatch all the way lets all the heat out; there is a definite draft going on there when parked in sunlight with a door or window open.

 

[Drew Bru]

We went with steel (16ga or 18ga IIRC). I was afraid Lexan would crack under the weight of the fan while rumbling down the road. Maybe not in the first few miles, but maybe after thousands of miles. I've not seen anyone who's put any real mileage on this setup. Would be easy enough to swap out metal, or seal it, if it does crack though I suppose. I just didn't want to have to figure it out on the road, and we kept our windows so light isn't a problem that needs to be solved.

 

[kazetsukai]

How does lexan hold up against hail?

 

[Mountain Gnome]

My friend introduced me to lexan. He used it in playgrounds that he maintained, where kids beat on it all day, it sits in the sun, rain, freezing, etc. If it cracks, it could hurt, even kill a kid.



He took a piece and threw it on the grass. He picked up a sledgehammer on a 3-foot handle, swung it over his head (he's a big boy at over 6' and 200lbs.), and smacked the lexan. It bounced off. He did it again, and it creased the lexan panel and it bent 30° - did not crack.


I also saw a video on YouTube where I guy tested a piece of lexan against bullet-proof glass, using a pistol. The lexan held up better.


I think a 2-foot diameter tree could fall on my roof, and it would take a 4" diameter branch on that tree to puncture the lexan, but only if the tree fell really fast.

 

[kellin]

How does lexan hold up against hail?

Hey Miko! This is actually Kellin from Windham. You fixed my brake lights last summer. I thought I recognized the bus in your profile picture then saw your location. You guys are on the road now I assume? Hope everything is going well for you guys and the cats!

 

[DoninTexas]

Emergency Exit Replacement

Has anyone tried one of these.


https://www.pplmotorhomes.com/parts...overs-vent-parts/exit-vents/exit-vent_31-1822


PRODUCT DESCRIPTION

Exit Dome Super 26x26

Item 31-1822 | MFR# 68631-C2
Large exit vents admit three times more fresh air than conventional-size dome vents. Vents open easily with either opening mechanism and hold at any position for air control. Available in opaque white with aluminum frame and four piece metal garnish, cut to roof thickness. Includes white plastic, leak resistant lids. #31-1829 has a plastic frame with 2-7/8" plastic garnish. #31-1827, #31-1803 and #31-1822 have metal frames with four-piece 2" white metal garnishes.

 

[o1marc]

How does lexan hold up against hail?

1/4" Lexan will stop a 22 caliber bullet, impervious to hail damage.
Tinted is the way to go, mine are and let in a lot of light.

 

[cushionhead]

I installed my MaxxAir into the old hatch and love how it turned out. It still bumps up a few inches for ventilation and it opens fully to access the rood deck. Here are a few pics.

 

[musigenesis]

I installed my MaxxAir into the old hatch and love how it turned out. It still bumps up a few inches for ventilation and it opens fully to access the rood deck. Here are a few pics.

This looks great, nice job.

 

[kuja]

1/4" Lexan will stop a 22 caliber bullet, impervious to hail damage.
Tinted is the way to go, mine are and let in a lot of light.

I'm looking to do something similar. I'd like to go with a tried and true source for material. I'm not sure if it's allowed to post the links, but if you could share that would be great!



Also, what did you use to secure and attach both items to one another (fan to Lexan, Lexan to roof)?


Thank you!