Installing Vent fans

[ktmossman]

I'm looking at installing the vent fans in the J. 

Has anyone installed the fans in the actual emergency exit hatch lids?

They seem to be fairly heavy duty plastic. They have plenty of surface area and the fans wouldn't prevent the hatch from fully opening.  I really want to keep the emergency exits and I'd rather not cut additional holes in the roof that I don't have to.

The only drawback I can think of is potential vibration noise, but there could be ways to mitigate that... 

But I've never done this before and I would hate to cut holes in the hatches and then realize I have to replace the hatches and still cut holes in the roof.

[richard5933]

I believe there is a thread about someone using the existing openings from the hatches to install an a/c.

I don't see any problem for a vent install into the hatch cover itself, as long as there was enough remaining material to maintain structural integrity.

[ktmossman]

The fan needs a 14x14 opening and the "flat" surface of the hatch is 24x32 (not counting the curve to the side).

[richard5933]

Vent fans are pretty lightweight, so it seems like it should be pretty reasonable to cut into the hatch cover, providing proper reinforcement is added to keep the hatch from cracking or weakening.

My MaxxAir Deluxe doesn't vibrate and operates smoothly, so I can't see how it would add undo stress.

[Jim Blackwood]

I'll probably do something along this line next summer on my DL3. I have a spare hatch from a '94 that I plan to use for prototyping. First step is to cut the perimeter rivets and separate the top and bottom, I may do that within the next couple of weeks.

Some means of restricting the opening angle is needed first, possibly gas struts. The fan can mount to the top surface or just below it, one of those plastic covers can go above that. Openings cut in the plastic inner cover should allow airflow.

Jim

[lvmci]

I used the hatches for AC, putting a metal plate over the hole. I figured out the fantastic vent fans needed exact locations, over the shower and over the stove, so Gary and Van cut hole in those places, watch out for the roof I beams running back to front inside the roof...

[somewhereinusa]

Not exactly what you asked for but this is how I made my fans using the escape hatch.