[ha3Dy_j1s]

So what are folks here who are insulating doing about the little pressure relief flaps on the lower rear quarters? Closing them off? Leaving an airway open and putting some kind of grill or opening on the finish panel?

And the hidden ones way down below the tail lights? Just leaving them alone and leaving the corner grills open and un-insulated? Or closing them off? Can you insulate around the bulbs? Do you want to? Tips and experience appreciated!

 

[Zoomyn]

Just a reminder those are more than 'pressure relief flaps' and work as a flow-through air path to keep exhaust fume ingress way low, the packed & stacked air around grill/windshield area gets metered sort-of proportionally into the compartment then drawn out into the following lower pressure slipstream. Again - those keep carbon monoxide levels down, remember it's cumulative and are a fail safe for operators doing eight/ten hour stretches driving in a closed vehicle or the young & infirm...

Leaving an easy path to its general area - a combination area of 1/4" gap eight or twelve inches plus along the liners etc, trying to equal the surface area of the rubber flaps would sure keep the passenger/cargo area a nicer place to spend time. Even be worth it to do a sturdy small speaker grill (w/o fabric dust screen) right smack over top of them.

 

[papab]

I have a 159 ext, it doesn't have those pressure flaps. Weird that that they put them in some but not all. It does have the hidden ones by the taillight You have to leave that area accessible. You might be able to put some thinsulate or something in there, but I t think those lights will get too hot. I just left it alone for now anyway.

 

[ha3Dy_j1s]

Got it. There's some little round aluminum vent covers with louvers I've seen at the hardware store in several sizes. I think they're used in soffits, etc. So the ones around 4" should be about right. They're inexpensive and should give a nice finished look, you just crimp the edges over on the backside. Could be painted I guess, but I'm okay with the aluminum. I'm thinking I'll pull the tall corner covers off and adhere the EZCool to the sheet metal (maybe a double layer) as far down as I can get access. That should give some insulation value and still allow air to flow freely to those lower vents.

I'm a little surprised the long van doesn't have the vents at the sides but the shorter vans do. Maybe those really are about relieving pressure when closing the slider as someone mentioned. Thanks guys.

 

[makevx73]

I'm a little surprised the long van doesn't have the vents at the sides but the shorter vans do. Maybe those really are about relieving pressure when closing the slider as someone mentioned. Thanks guys.

It seems pretty random actually. My 118" doesn't have them.

Those side vents by the wheel wells are for pressure relief of door closing. Nowhere near enough flow for anything else.

 

[jostalli]

I have the side vents in my 159 standard length. I didn't insulate over them but I'm going to cover them with paneling and cabinetry. When I bought the van the vents were covered with plywood paneling and I didn't notice any more difficulty closing doors but maybe I wasn't paying close attention.

 

[stonehopper]

It seems pretty random actually. My 118" doesn't have them.

Those side vents by the wheel wells are for pressure relief of door closing. Nowhere near enough flow for anything else.

Does your 118 have the louvered vents behind the bumper? I remember a posted picture here that shows them, mine does not. It's a definite straight path for my diesel exhaust gas to get into the cabin, which does when I open the windows. I haven't had time to stop by the dealer to peek under a new unit on the lot to see how they are built.

 

[ha3Dy_j1s]

It seems pretty random actually. My 118" doesn't have them.

Hmm. Surely there's room for it on the 118". Could it be a model year thing? The '14s had too much trouble closing the slider so they added them to the '15s? Mine's 2015/136"/with. It still takes a real firm pull to get the back end to latch if the van's closed up.

 

[ha3Dy_j1s]

Leaving an easy path to its general area - a combination area of 1/4" gap eight or twelve inches plus along the liners etc, trying to equal the surface area of the rubber flaps would sure keep the passenger/cargo area a nicer place to spend time. Even be worth it to do a sturdy small speaker grill (w/o fabric dust screen) right smack over top of them.

While checking the "Source for Rear Door Windows" thread I came across this:
http://www.etrailer.com/p-371800.html
This might be a very good solution. Could leave it normally open but close it when camping in temperature extremes, etc. Looks like the opening would be roughly equal to half the area of a 6" hole, which sounds fairly close.

 

[makevx73]

Does your 118 have the louvered vents behind the bumper? I remember a posted picture here that shows them, mine does not. It's a definite straight path for my diesel exhaust gas to get into the cabin, which does when I open the windows. I haven't had time to stop by the dealer to peek under a new unit on the lot to see how they are built.

Can't say. I'll have to look sometime. Don't think so though. I've had the bumper apart to install a hitch and can't say I saw anything.