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Fresh air flow.

Posted: 13 Dec 2017, 21:14
by bigbadbob76
I'm tempted to add some fresh air vents in the back of my panel van camper conversion as we get a lot of condensation back there when sleeping.
Looking at this pic-

Image

The fresh air flow seems to be from the front grill- across below the dash-through the doors-up the B posts and along the top level with the gutters.
Can anyone confirm this and whether it then connects to the exterior vents in the D posts?
I don't have the fourth heater vent control lever so assume i always get fresh cold air through there.

If I was to fit interior vents in the back sides, up near the roof, would I get engine smells coming into the van?
Cheers.
BBB.

Re: Fresh air flow.

Posted: 14 Dec 2017, 10:43
by sarahandthebear
Hello don't know if this link will help at all but I was trying to do a bit of research for you and stumbled across this
http://www.gowesty.com/tech-article-details.php?id=83" onclick="window.open(this.href);return false; I think you may have engine smells if you use the back vents the warm air rises and often after a drive you can small it as you walk past the vents so you may get some smells in the van unless you could close the vents when you wanted sorry if this isn't no help at all but when we first got our van I was reading the Haynes manual about the heating system also some good information and diagramed in there

Re: Fresh air flow.

Posted: 14 Dec 2017, 10:55
by multisi
Why would you get an engine smell ? The vents use air from the front of the van , the air ducts up near the roof aren't connected to the engine bay. The early Aircooled engine van could produce an engine smell from the heat exchangers into the van if there was oil dripping onto the exchangers or if the connections were loose.

Re: Fresh air flow.

Posted: 14 Dec 2017, 11:47
by sarahandthebear
Yeah just been looking at the diagrames online you are right you would not get an engine smell as multisi rightly said unless you have an air cooled with a heat exchanger but with a water cooled you will have no problem :ok

Re: Fresh air flow.

Posted: 14 Dec 2017, 12:23
by DavidPallister
I think the 4th heater lever opens a flap in the bottom of the heater box to divert air into the front cross beam, and from there through the door beams, up the b posts and into the top rear vents.

With no 4th lever, the air won't get in to that part of the system.

Also, those vents are in no way attached to the rear engine vents.

Dave

Re: Fresh air flow.

Posted: 14 Dec 2017, 16:37
by bigbadbob76
Thanks everyone. :ok
Your confirmation that "the air ducts up near the roof aren't connected to the engine bay" and variations on that theme is re-assuring.
So I should be able to fit vents above the rear side windows.
Not having the 4th lever... I'm hoping i'll still get fresh air up there just not hot air from the heater core.
I'll check if I get any flow from the door vents next time I'm out, I always leave them shut so have never noticed if there's any fresh air coming out.
Although looking at the go-westy link it looks like these are air exits not inlets. hmmm.... interesting link Sarahandthebear. :D

Re: Fresh air flow.

Posted: 14 Dec 2017, 16:54
by multisi
Sounds like you need a square motorhome roof vent on the actual roof, the little air duct vents aren't going to get rid of the condensation. I have an old fiamma vent if you go down that route.

Re: Fresh air flow.

Posted: 15 Dec 2017, 09:24
by bigbadbob76
Thanks for the offer Multisi.
That would definitely give me the best ventilation but I really don't want to cut holes in my roof.
It's a virgin unmolested tin-top and I don't want to violate it. :lol:
I could maybe run some ducting up the D pillars and put vents in there as long as the ducting draws from somewhere away from the engine.
Vents in the tailgate would be an option too but would probably look crap.
An opening tailgate window would be a nice option. has anyone seen it done?

Re: Fresh air flow.

Posted: 15 Dec 2017, 09:48
by multisi
You need to get some windows that open, looking at photos of your van with fixed windows and no roof vents I'm not surprised it gets a bit sweaty in there !

Re: Fresh air flow.

Posted: 15 Dec 2017, 10:42
by itchyfeet
Condensation ...yeh yeh....Ffffffffffffffrrrrtt. :D

Re: Fresh air flow.

Posted: 15 Dec 2017, 11:23
by Mocki
i have those upper vents in my camper ( ex caravelle gl) they only provide cold air, and only when the van is moving
and unless you are parked facing a brisk wind nothing comes out other wise when staionary.
you dont need the 4th control though i dont think, as the vents in the bottom of the doors work all the time , but you will need the ducting and seals for the "B" pillar and roof

Re: Fresh air flow.

Posted: 15 Dec 2017, 17:18
by dave friday
You need to fit an extractor fan/tailgate lock open thingy...
Would be nice if the heater motor could be made to suck instead of blow!

Re: Fresh air flow.

Posted: 15 Dec 2017, 17:38
by marlinowner
As above

https://www.brickwerks.co.uk/tailgate-stand-off-t3.html" onclick="window.open(this.href);return false;

Re: Fresh air flow.

Posted: 15 Dec 2017, 20:26
by lefty67
We had the thermal window covers in the previous van which helped to cut down the condensation. Just used them on the rear and side windows.
Don't have much of a problem in current van as have a roof vent and wind deflectors so can leave windows open a bit.

Re: Fresh air flow.

Posted: 15 Dec 2017, 21:14
by bigbadbob76
itchyfeet wrote:Condensation ...yeh yeh....Ffffffffffffffrrrrtt. :D

It was the dog. :P

We have wind deflectors on the front so can leave them open a bit and a sliding window over the sink so can do the same there but really want some small vents somewhere at the back that we can cover with fine mesh to keep midgies out and not get lashing rain in.
Maybe a short ducted vent from inner skin to the top of the exterior vents.
Propping the tailgate would be a bit too much ventilation methinks, good suggestion though. :ok
Cheers for the heads up on the vents Mocki. :ok