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Dusty road problem

PostPosted: Thu Dec 20, 2007 1:31 am
by 4123
So...Here is my first post. (2nd?) I do a lot of off road driving and camping. One of the problems I've encountered is dust making its way inside the trailer. To combat this, I've been thinking about 'pressurizing' the inside of our teardrop. I will use a low pressure, high volume, 12 volt air pump, similar to what is used to inflate river rafts. There will have to be an automotive type air filter on the intake end of the air pump mounted as far forward on the trailer as possible. Also, a small opening between the galley and sleeping quarters to equalize the system. What I am hoping for is air pressure to be blowing out through any microscopic holes or cracks that would normally allow dust to enter. The pump will be turned on via a switch in the tow vehicle, wired through the trailer plug connector. When you hit the dusty road, simply throw the switch...
Is there anyone out there who have already done this? Any suggestions would be appreciated.
Thanks, Ron

PostPosted: Thu Dec 20, 2007 1:46 am
by Juneaudave
I haven't heard of anyone doing this, but it would probably work if you have a closed filtration system that feeds dust free air into the cabin for pressurization, otherwize you're only sucking dusty air in and making things worse.

I'm up in Juneau and have a similar problem with "Wet". I'm focusing on making my door and window seals as tight as possible so they don't leak. That might be a better solution!!!
8)

PostPosted: Thu Dec 20, 2007 10:03 am
by Gerdo
If the pump is inside the TD then it is using the air inside. You are taking the same volume of air, compressing it and releasing it. You will be using as much volume as you are making. There will be ZERO pressure change. But if the air supply for the pump was oudside of the TD then it should work.

I would look for where the dust is coming in and seal it. You should see trails of dust where it is coming in. I'm thinking of adding some vents but they would have screw on covers to seal them.

PostPosted: Thu Dec 20, 2007 10:48 am
by caseydog
Unlike water, dust can come in from anywhere because it "floats" in the air and is carried BY the air. It is amazing how it gets into places you thought were well sealed off.

The pressurized cabin idea sounds good. You'd have to have a really good filter, and clean the filter often to keep dust from coming in through your pressurization system. However, if you make it right, it should be effective.

Another option is a filtration system INSIDE the cabin that runs all the time. You would be removing the dust from the cabin air while it is airborne, so most of the dust does not get a chance to settle inside the cabin.

Good luck.

clean air

PostPosted: Thu Dec 20, 2007 4:28 pm
by legend lime
You could install the pump under the hood of the tow vehical with a cold air duct to the front of the vehical with a filter; same as the intake for the eng, then run a hose under the vehical back to the rear of the vehical with a quick disconnect connector. Mount another hose to the tongue of the tear drop then into the inside of the tear. this way you are pulling the air in prior to any dust (unless you are behind someone else) but then that's what the filters for.

PostPosted: Thu Dec 20, 2007 6:28 pm
by angib
My suspicion (this is all theory, yeah? - no practical experience) is that the doors are at a higher pressure than the hatch which is in the low pressure wake. So I'd expect air to be trying to flow in past the door seals, through gaps/holes in the bulkhead and then out past the galley hatch.

So one thought is maybe you could cut the dust by sealing the bulkhead thoroughly, so that the airflow is stopped. Taping up every joint and seam in the bulkhead with masking tape might be a test worth trying, to see if it stops/reduces the dust problem. I guess taping up either the hatch or the doors would also test it, but I'm not sure why I feel less confident about those two.

If you pinned down that it was airflow doing it, then caulking the bulkhead might be a simple long term solution - unless you've got a hatch in it!

Andrew

PostPosted: Fri Dec 21, 2007 11:09 am
by Wos
My family owned a van when I was a kid and my mother has a severe dust allergy. We had a vent on the roof of the van that would open at the back, tilting up like most vents I've seen on this site, causing a vacuum effect that would pull air in from all the other holes (seals, vents etc) in the vehicle. It also opened at the front, like a ram hood on a dragster, which would pressurize the vehicle. It kept the dust out entirely. This would probably work on a teardrop if the tow vehicle didn't cause to much dust to be thrown over the roof of the tear. Even then it may force more out than it draws in.

PostPosted: Fri Dec 21, 2007 3:30 pm
by Miriam C.
Wos wrote:My family owned a van when I was a kid and my mother has a severe dust allergy. We had a vent on the roof of the van that would open at the back, tilting up like most vents I've seen on this site, causing a vacuum effect that would pull air in from all the other holes (seals, vents etc) in the vehicle. It also opened at the front, like a ram hood on a dragster, which would pressurize the vehicle. It kept the dust out entirely. This would probably work on a teardrop if the tow vehicle didn't cause to much dust to be thrown over the roof of the tear. Even then it may force more out than it draws in.


:thinking: Anyone want to put their vent on opening to the front and see if this works. Might work if the lid doesn't blow off. I have resisted running down the dirt roads I really prefer to keep out the dust. Well I did it one time and got dust everywhere. :D But had gaps everywhere too.

PostPosted: Fri Dec 21, 2007 3:59 pm
by PaulC
angib wrote:My suspicion (this is all theory, yeah? - no practical experience) is that the doors are at a higher pressure than the hatch which is in the low pressure wake. So I'd expect air to be trying to flow in past the door seals, through gaps/holes in the bulkhead and then out past the galley hatch.

So one thought is maybe you could cut the dust by sealing the bulkhead thoroughly, so that the airflow is stopped. Taping up every joint and seam in the bulkhead with masking tape might be a test worth trying, to see if it stops/reduces the dust problem. I guess taping up either the hatch or the doors would also test it, but I'm not sure why I feel less confident about those two.

If you pinned down that it was airflow doing it, then caulking the bulkhead might be a simple long term solution - unless you've got a hatch in it!

Andrew


Andrew, is'nt that called the "bernoulli effect"?
Cheers
Paul :thumbsup:

PostPosted: Fri Dec 21, 2007 10:25 pm
by Wos
Miriam C. wrote:
Wos wrote:My family owned a van when I was a kid and my mother has a severe dust allergy. We had a vent on the roof of the van that would open at the back, tilting up like most vents I've seen on this site, causing a vacuum effect that would pull air in from all the other holes (seals, vents etc) in the vehicle. It also opened at the front, like a ram hood on a dragster, which would pressurize the vehicle. It kept the dust out entirely. This would probably work on a teardrop if the tow vehicle didn't cause to much dust to be thrown over the roof of the tear. Even then it may force more out than it draws in.


:thinking: Anyone want to put their vent on opening to the front and see if this works. Might work if the lid doesn't blow off. I have resisted running down the dirt roads I really prefer to keep out the dust. Well I did it one time and got dust everywhere. :D But had gaps everywhere too.


My words seemed a little inadequate. The vent we had had two ways of opening, the back end lifted up just like most of the ones I've seen here and the front also had a door panel on it. The whole thing looked a bit like a teardrop with a flat face that opened. The front was only 3"x 12" or so. When it was open to pressurize you could hold your hand up and feel the air coming in.

PostPosted: Sat Dec 22, 2007 11:23 am
by schaney
Ron, IMHO pressurizing the cabin is way over kill. I would chaulk the gaps and use good door/window seals. I use EPDM "D" or 5-rib seals on my doors and have no dust problems. For really dusty situations I'd go with the 5-rib seal
Image

Both MD (available at Home Depot) and Trim-LoK make a ~3/8 x 5/8 version of it.

One trick for sealing again dust an "old timer" told me, was to smear your seals with vasoline. A little messy for my taste, although I find keeping them regularly rubbed down with 303 Protectant does help.

PostPosted: Sat Dec 22, 2007 1:04 pm
by jdarkoregon
Scott, great advice and I'm with you.

Soft gaskets on all the openings should take care of the problem. I admit that sometimes a person will have to customize the gasket fit. Especially with the homebuilt.

John