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Question about the interior Vents in back of Van.

31K views 26 replies 18 participants last post by  RyRy  
#1 ·
I have not yet purchased a PM, but I have noticed a few mentions of the black plastic "vents" that are alongside the rear cargo doors. Apparently they are one way vents that enable the doors to close with greater ease.

My question is can these vents be manually held open? If not how difficult would it be to modify them?

I'm planning an RV build that would have a raised bed in the back of the van and would like to incorporate vents into that area to get air flow from the exhaust fan I plan on having in the front. If these vents can somehow be held open that would save a lot of work.
 
#4 ·
I believe that you are talking about the wrong "vents".

The vents used to release air pressure to make it easier to close the doors are visible behind the wheel well on each side wall of the van, about 6" up from the floor. They have paper-like white flaps that vent high pressure inside to the outdoors. They are about 5" or 6" square black plastic.

They are not visible from the outside because they are covered by the wide black plastic trim molding behind the rear wheels.

It would be easy to force always open, but I would guess that some things (ie. bugs, mosquitoes, etc.) could use them as an entry point. Also heat and AC could escape in or out of them, if they are always open.
 
#5 ·
These are the vents I was looking for, I just assumed they were located along side the doors as opposed to near the floor. I would have to extend them since they are so close to the floor, but they may still work. I could just add shut offs and an internal screen somewhere in the extension to keep the bugs out.
 
#10 ·
Mine were there, but I didn't see them until someone called them to my attention. You need to look in the area on the side wall near where the back of the wheel well meets the floor.

As I said, "They are not visible from the outside because they are covered by the wide black plastic trim molding behind the rear wheels.", but they do vent air to the area behind the molding which is open to outside air.

I have a high roof, but I think I have seen them on all the PM vans I've looked at.... all roof heights.

Ed
 
#14 ·
My 159 hightop EXT does not have them.

The doors were a pain to close until i installed roof vents. All the PMs I looked at on the lot had the vents but my PM showed up without them. Its just one of the fun little mysteries of the PM, right up there with the missing passenger arm rest;)

Should you be lucky enough to receive the mystery vents, you may find that its more trouble than its worth to access them and the flow is pretty small/restricted. I will be installing a floor vent.

Dave
 
#15 ·
Hehehehe.. I cut them out and made 6" holes on both sides. Original plan was to use a portable AC and use one as the intake and one as the exhaust. Didn't work. Even after I did my insulation the van heated up faster than the AC could cool it off enough to keep the AC from shutting down on high temp.

Now going to use them as intake and exhaust from a generator box to power a window AC through a back window.

It would be very easy to make them allow air both ways.. There is are small plastic flaps inside the vent and if you remove the rear quarter panel rubber trim you can get to the screws for the vent. Take if off and simply remove the flaps.
 
#18 ·
Some seem to have rear vents on the side walls, just behind the wheel wells I think. Others have rear vents down low inside the rear corner pillars. That's where mine are. I think I read that some have vents in both places, not sure about that. From your description, it sounds like your vents are on the side walls.

I wonder if the flaps can also be removed from the vents in the pillars. Not much room to work in there. If the flaps can be removed, is there still a screen to keep pests out, but still allow 2-way air flow?
 
#17 ·
Humnnn,, There are lot of vehicles with generators in boxes inside of vans. All a high end RV is is a big van and all of them have generators, sometime 10KW ones, in boxes inside the body of the "van".
I am planning a 2.1KW remote electric start one. I will also pipe the generator exhaust directly to the outside. There will be a 6 inch auxiliary ventilation duct fan on one side pulling air in the other side directly into/onto the generator. This will put the box at a negative pressure compared to the inside of the van, so even if I don't manage to get a perfect seal (super expanding fire wall foam should give me a very good seal) I shouldn't have any exhaust gases get into the van.

The electrical setup will be that when the generator is running, the exhaust fan will be running and I will have a remote temperature and CO2 monitor in the box.

I have a friend that has spent 30+ years working on RV's advising and helping me. My friend says he can get me an RV generator monitor that has an output to kill the generator if the fan loses power or the CO2 or Temp get too high in the box.

This might want to be a separate thread.
 
#20 ·
I too am doing a conversion of my 159 HT. I noticed the vents pretty quickly while planning out my build. I also noticed the "flapper valves" that are hinged to release (open) any positive pressure inside the van, and close by gravity to keep the creepy crawlies out. When I installed the roof fan, I checked the valves and sure enough, open when the fan is blowing in, closed when exhausting air from the van. I ended up performing "surgery" and basically, ripped out the flapper valves, leaving the housing. I then glued a fine mesh screen over the existing slots on the housing. Big change in exhaust airflow which should be better for cooling the interior during moderately warm days. When I install the panels over the vents, I'll be cutting a hole and adding a mesh cover.
 
#21 ·
..."flapper valves" that are hinged to release (open) ...ended up performing "surgery" and basically, ripped out the flapper valves, leaving the housing. I then glued a fine mesh screen over the existing slots on the housing...
Reading through the DIY ideas...
I'm going to look behind the panels on our 2017 159 RB. I like the idea of performing "surgery" to use pulling in or letting out air. There is a fellow over at the Transit forum (Orton) who is pro-floor vents in conjunction with upper vents for circulation, and has them in his DIY build.

On safety? I'm doing some searches on google but coming up empty so far, i was thinking of placing a couple of passive vents in the back upper van wall above door line but wondered if (as i recall in some earlier car designs) that exhaust fumes could easily intrude into cabin while driving. Do you think this could be the case with the PM design/air flow behind van?

THX in advance for any tips/comments.
Thom
 
#23 ·
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I know this is an old thread but for those of you who have pulled the flappers out of the rear factory installed vents, How has this worked out for you over time? does it get dirty/dusty? any exhaust gas issues? Enough airflow?
i just realize today that these vents actually connect outside and i also removed all the flaps to try the same thing.
Thanks!
 
#24 ·
I would not remove the flap on the vents. You do not want to have exhaust has coming in while you are driving. Carbon monoxide has is bad news. It is cumulative in your blood stream.
Of you want get some air flow from low in the van when parked maybe think about a 6-8" round boat access port in the floor with some screen.
 
#25 ·
I doubt much exhaust fumes would flow that way while idling (no more than your rear doors would allow in if not completely sealed, or your other windows would allow other vehicles fumes, but not prolonged exposure concern), and barring any extreme winds or exhaust modifications you should be driving away from your exhaust while moving. Gases 'could' drift that way, but I doubt the little paper flaps would prevent much from entering if it did anyway.

Not to diminish carbon monoxide poisoning, nor the fact that any hole should be able to close - both good points from mtbiker. If you've already removed the flaps, I'd install a manual cover of some sort. Without modifications, I'm fairly certain the hole is bigger inside than outside. It could be part of a ventilation solution, but unlikely a very large part