Pressure hatches and Bull dust
Submitted: Sunday, Oct 24, 2010 at 18:49
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bluefly
Having a so called pressure hatch open on the roof of a camper van has always perplexed me.
Not all that long ago we tried it out on a bull dust section.
Never ever again! The van was saturated in bull dust (on the inside) in comparison to other trips in similar conditions.
Obviously all vans have vents, and I’ve sealed these up from time to time with bubble wrap, which has reduced the entry of bull dust to some extent.
Then I came across a response from the Kenron Boys on another
forum debunking pressure hatches as a load of nonsense.
I’ll never open a pressure hatch again in bull dust sections, but I would like to hear the thoughts from others.
PS Please be mindful that I’m talking about Bull Dust and not normal road dust.
Cheers
Reply By: Sand Man (SA) - Sunday, Oct 24, 2010 at 19:26
Sunday, Oct 24, 2010 at 19:26
There is a vast difference between a pressure vent on a vehicle and one on something being towed.
When relatively clean air is forced through a vent, or even a cracked open window of a chassis cab the positive air pressure will stop dust being sucked in through even small openings in a tailgate, etc.
When you are towing a camper or caravan, the dust from the towing vehicle wheels will create a "cloud" that will then be forced into the "pressure vent" on the towed object just behind it.
That's my experience anyway.
I have a vent on the forward section of my canopy and I don't get any noticeable dust in
the tub section.
Unfortunately, on a recent trip through the
Gawler Ranges I neglected to open the small vent and the result was a significant amount of bull dust being sucked in to
the tub area.
Bugger!
Bill.
AnswerID:
434089
Follow Up By: bluefly - Sunday, Oct 24, 2010 at 19:43
Sunday, Oct 24, 2010 at 19:43
Bill
I think you misunderstood my post. I was talking about camper trailers and caravans, not hubs on a verhicle.
Cheers
FollowupID:
705118
Follow Up By: bluefly - Sunday, Oct 24, 2010 at 19:55
Sunday, Oct 24, 2010 at 19:55
Oops I miss read your post.
Cheers
FollowupID:
705120
Reply By: Member - Christopher P (NSW) - Sunday, Oct 24, 2010 at 19:39
Sunday, Oct 24, 2010 at 19:39
I saw on here a great idea. It's called positive pressure, what they did was use a car air cleaner that was round and they used some computer fans to pressurise the camper van or trailer.
some ideasanother one
AnswerID:
434090
Reply By: KiwiAngler - Sunday, Oct 24, 2010 at 20:47
Sunday, Oct 24, 2010 at 20:47
Hi Bluefly
I have just ordered a Conqueror UEV 490 and in their video they show a fan mounted on the side of the CT that you turn on to 'pressurise' the CT
I havent got my Conqueror yet so cannot say if it works or not but the logic seems ok
Thsi video shows them referring to it
Conqueror Video Link
Cheers
KA
AnswerID:
434095
Reply By: Notso - Sunday, Oct 24, 2010 at 21:02
Sunday, Oct 24, 2010 at 21:02
I've had a pressure hatch in two vans so far.
To be honest I don't know whether they work or not, but with regard to the dust swirling up over the van, I haven't seen that yet.
The majority of the dust seems to pass beside and under the van before it swirls up above van height.
Anyhow, I haven't had a major dust entry problem yet.
AnswerID:
434100
Follow Up By: Member Boroma 604 - Sunday, Oct 24, 2010 at 21:31
Sunday, Oct 24, 2010 at 21:31
Gooday,
Have a 21ft hardtop caravan, came with 1 pressure hatch, first trip across Great Central in 2005 was like a vacuum cleaner. When I came back I got the builder to put another 2 hatches in,
The original was about 6X4". Next 2 are about 8"X5". Just completed 14500KM, 2700 on gravel, including Donoghue/Plenty, Great Central Rd, various other gravel stretches in WA, then The Tanami back to Alice, would have come back to
Brisbane via Plenty only it was closed due to rain. On the gravel I opened all 3 hatches, had a piece of corflute full length between screen & outer door, taped over the other couple of vents and had virtually no trouble with dust. The secret is to have enough air coming in to pressurise the interior.
Yes a pressure fan working on the inside would be superior but there were none about when we had the caravan built.
Cheers,
Boroma604.
FollowupID:
705132
Reply By: Peter_n_Margaret - Sunday, Oct 24, 2010 at 21:50
Sunday, Oct 24, 2010 at 21:50
We have a pressurising vent at the top, front of the bed-over of the OKA that is permanently open to ram air.
We get virtually zero dust inside the living area (which is sealed from the driving compartment which gets LOTS of dust).
Cheers,
Peter
AnswerID:
434107
Reply By: MEMBER - Darian, SA - Monday, Oct 25, 2010 at 09:43
Monday, Oct 25, 2010 at 09:43
Nope - the 'Kenron Boys' (Gall boys, Kedron ?) are wrong if they said that about pressure hatches. Set up right, they can work very
well.
AnswerID:
434138
Reply By: kiwicol - Monday, Oct 25, 2010 at 19:55
Monday, Oct 25, 2010 at 19:55
Hi,
The coaches that travel on dirt roads have a Donaldson air cleaner with a fan built in high up on the roof which forces clean filtered air into the luggage compartments below floor level. They work fantastically, have seen the mess when the units break down.
I have the same unit fitted to my skid steer loader, pushing clean filtered air into the aircon, which also pressurises the cab, keeping out the dust.
Cheers Col
AnswerID:
434192
Reply By: Member - Graham H (QLD) - Tuesday, Oct 26, 2010 at 10:28
Tuesday, Oct 26, 2010 at 10:28
The main problem as I see it is that you have a small scoop trying to pressurize the inside of the van and have several vents that are much larger defeating the purpose.
EG the LPG vent in the bottom of the door. ( Illegal to cover up) the one in the bed area near the roof, the one behind microwave, leakage around the fridge sometimes.
Like pushing the proverbial up
hill with a rake sometimes.
Yes I know we all cover the one on the door but one day may cause you to wake up dead if stove leaks in the night.
Havent had any trouble so far and the pressure hatch wont open on my van anyway.
AnswerID:
434249
Reply By: garny - Wednesday, Oct 27, 2010 at 20:04
Wednesday, Oct 27, 2010 at 20:04
Hi Bluefly
i have a windsor rapid pop top and have fitted a 12 volt 9inch fan inside sucking through a air cleaner ellement this in conjunction with the top hatch opened this allows the van to equalise when travelling slowly on dirt roads the higherthe fan can be mounted the better.
regards Garny
AnswerID:
434381