Fabricating a powered dust filtration system?

[John E Davies]

Please send me to a thread if this has been discussed.

I am going to be buying an Oliver travel trailer and will have _abundant_ solar and battery power.

I was wondering if there are plug and play powered dust filters available to pressurize the cabin (minimizing dust infiltration) while towing on dusty roads, or if I could build my own using a universal heater blower kinda like this?

I really don't know how to design the air intake, what kind of filter to use, and where to mount the intake. It would have to be in clear air, not necessarily positive pressure, but certainly not inside the dust cloud down low.

Kimberley uses an exotic system powered by compressed air. I do not want to design a starship, just a simple 12 volt forced and filtered induction.

I am imagining a Safari Snorkel head facing forward out of the top of the roof, with a dust pre filter. The duct goes down to a filter airbox in the front closet, then to the fan and into the cabin. The snorkel head would have to be easily removed and the hole weather tight. Maybe mount it to a round marine deck plate?

As tight as an Olliver is built, I think this would pressurize the cabin enough without having to plug up all the outside vents.

Am I crazy? To be honest I haven't heard stories of inside dust being a problem, but the vast majority of them don't ever venture off pavement. If I post a question at the Oliver Forum they will just laugh. I'm just wondering at this time.

Thanks for any comments.

 

[Rutdigger]

This is interesting. The UEV 440 has a pos air system in theirs to keep the dust from entering the trailer. I was actually thinking of building one myself. This will be interesting on the ideas ppl come up with to make it. As for the filter I plan to use a K&N type filter. Flow is good elevating high amp draw on the fan I use.

 

[John E Davies]

You might consider an airbox from a car of some kind or Shop-Vacuum cartridge to utilise standardised available anywhere filter element.

The car airbox is a GREAT idea. Here is a complete Second Generation Dodge Ram Cummins airbox assembly from eBay for US$80.

http://www.ebay.com/itm/94-02-Dodge-Ram-Cummins-Diesel-Air-Filter-Airbox-Intake-Complete-Factory-OEM-/321948901806?hash=item4af5a661ae:g:G7QAAOSwcBhWbvWW&vxp=mtr

It's compact yet has a very large, affordable, easy to replace paper filter and a restriction gauge that shows you when to replace it. I think something like that would work great. If you were determined to have a washable filter, you can easily find those. But I think having a foam pre filter at the air inlet would negate that issue. You would want a paper element in the airbox for getting out the finer particles. You can blow the paper filter reasonably clear with compressed air, a few times anyway.

Here's the filter
http://www.genosgarage.com/product/af25541/air-filters

Here's a compact 3 inch, low amp bilge pump that flows 130 cfm of air, and it's cheap.

http://www.amazon.com/Marine-Electric-Bilge-Blower-130cfm/dp/B00F7ANK7S

Manufacturers specs:

http://www.seaflo.com/en/productDetail_350.html

Snorkel head 3 inch:

http://www.ebay.com/itm/Snorkel-Head-Air-Ram-Head-3-77MM-Safari-Airtec-Airflow-all-brand-replacement-/291410181330?hash=item43d9667cd2:g:ByoAAOSwGotWpoLp&vxp=mtr

Foam pre filters:

http://www.ebay.com/itm/2-X-UNI-FILTER-Safari-Airflow-Toyota-Snorkel-Ram-Head-Cover-Precleaner-Filter-/331646724703?hash=item4d37af6a5f:g:WKgAAOSwKtlWjfvj&vxp=mtr


John Davies
Spokane WA USA

 

[Korben]

Idea for ya, might as well do a combination unit with a vacuum. I'm betting you'll appreciate a vacuum and with an air pump and filter you're half way there anyway. So why not do something like snag all the parts for the HondaVAC out of a wrecked Odyssey. Set it up in your new Oliver with the addition of the snorkel intake thing and a way to switch the suction side between the vacuum hose and the intake.
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Or...
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I don't know what your tow vehicle is or if you're up for modifying it but maybe use it's HVAC system. For example some rigs have(or some install aftermarket) separate rear systems, connect it with a flexible hose from the tow rig to trailer and you can not only pressurize the trailer but it'll be warm(or cool) already when you stop.

 

[John E Davies]

Idea for ya, might as well do a combination unit with a vacuum. I'm betting you'll appreciate a vacuum and with an air pump and filter you're half way there anyway. So why not do something like snag all the parts for the HondaVAC out of a wrecked Odyssey. Set it up in your new Oliver with the addition of the snorkel intake thing and a way to switch the suction side between the vacuum hose and the intake.
.
Or...
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I don't know what your tow vehicle is or if you're up for modifying it but maybe use it's HVAC system. For example some rigs have(or some install aftermarket) separate rear systems, connect it with a flexible hose from the tow rig to trailer and you can not only pressurize the trailer but it'll be warm(or cool) already when you stop.

The Honda vac is interesting, but I bet the amp draw is pretty darned high and it couldn't run continuously, no way. It would burn up.

My tow vehicle is a Ram pickup so a rear hose would be a little too Rube Goldberg. I could run my generator in the bed and power an electric leaf blower.....

John Davies
Spokane WA USA

 

[DUTCH]

Kimberley uses an exotic system powered by compressed air. I do not want to design a starship, just a simple 12 volt forced and filtered induction.

Actually, Kimberley Karavans use a simple air scoop on the top of the van where it is located above the majority of dust. See the attached photo.

The air pressure when moving is the only power. They use a simple replaceable lawn mower engine intake air filter on the inside to eliminate any dust that might come in the scoop.

It works well, but can let water inside it you're driving in a rain storm.

 

[John E Davies]

Actually, Kimberley Karavans use a simple air scoop on the top of the van where it is located above the majority of dust. See the attached photo.

The air pressure when moving is the only power. They use a simple replaceable lawn mower engine intake air filter on the inside to eliminate any dust that might come in the scoop.

It works well, but can let water inside it you're driving in a rain storm.

Here is the one I was referencing, it is over-the-top complicated, but I bet it works well.

Kimberley's “Always Positive” System
Always positive presurisation system to minimize travel dust This has 3 components interconnected like a series of water falls:
A high pressure tank with air at 40-50PSI. This is the same tank used for the Air Suspension if fitted. A small compressor will occasionally come on and re-pressurize this tank.
The tank has a pressure regulating valve that fills a very large volume “bladder” at 3-4PSI very quickly. The Bladder is a specially formed lightweight PVC unit.
An automatic flow control valve connects the bladder to the inside of the caravan. Air from the bladder automatically bleeds through with a smaller pressure (0.1PSI) increase inside over the outside.
The primary air filter is fitted outside as an air-cleaner before the compressor.
The compressor doubles up as a tyre-inflating device.

The Bladder is a PVC construction but with the special stringed PVC layers that keep a flat shape. It sits in the upper section of the front tunnel boot and is 1500mm x 700mm x 150mm deep. It weighs only 3.5kgs.

The compressor and pressure regulator come on only when the vehicle is connected to the caravan and the ignition is on with a signal to the caravan.

It takes seconds to activate.

This is standard on the Black Caviar Model and an upgrade on the Classic Model.

Buyers Please Note:

It is realistically impossible to 100% barricade all the dust and some air will always pass through the filter with some dust. we would have liked to say that we are dust free but we cant. What we can say is the amount of dust is absolutely minimized.

http://www.kimberleykruiser.com/anti-travel-dust

John E Davies
Spokane WA USA

 

[DanCooper]

Now this will be interesting to watch . . .

 

[DUTCH]

Here is the one I was referencing, it is over-the-top complicated, but I bet it works well.
John E Davies
Spokane WA USA

Waaaaaaaay overly complicated, if you only want to minimize dust. The top air scoop mentioned above works very well, and it's one less thing to break down.

 

[OCD Overland]

The Oliver has a fan on one of the fridge vents already, so I don't know if that could be utilized in some way. As it is, I wonder if it runs while underway if it would actually pull dust in. I don't know how well sealed the back-of-fridge space is from the main cabin. I've been curious about water intrusion there also.

You also have the MaxxAir fan and the A/C to either worry about or use to your advantage, and there's a powered vent in the bath. I don't know if those rooftop AC units have a fresh air intake or not, but the MaxxAir has no filter at all, just an insect screen, and I don't know how well it seals when closed - BUT - the MaxxAir airflow can be reversed, and possibly you could do the same with the bathroom vent by reversing the polarity - put a filter on either and you'd be set. The MaxxAir could give you 900cfm - that should do it, lol - and could probably be run in the rain, even while underway. If the range is good enough, you might even be able to use the remote to control the MaxxAir from the tow vehicle. Now wouldn't that be sweet.

Or maybe Oliver would install a second pop vent like in the bath and just have that polarity permanently reversed.

It's worth asking Oliver about some sort of air filter on those fridge vents, regardless of what you do to pressurize the cabin.

I can't understand the Kimberley setup at all. One thing I'm beginning to suspect about them is that if Bruce has the choice of building something with 1 part or 5, he'll pick 5 every time.

 

[John E Davies]

The MaxxAir could give you 900cfm - that should do it, lol - and could probably be run in the rain, even while underway. If the range is good enough, you might even be able to use the remote to control the MaxxAir from the tow vehicle. Now wouldn't that be sweet.

Or maybe Oliver would install a second pop vent like in the bath and just have that polarity permanently reversed.

It's worth asking Oliver about some sort of air filter on those fridge vents, regardless of what you do to pressurize the cabin

All interesting comments, tho I doubt that I would need to run any dust filtration system in the rain..... LOL.

I have only communicated by email with Oliver, if I were to visit the factory, an unlikely event due to the distance, I could probably get a bunch more detailed information. I know they will not mess with the suspension other than Dexter factory parts. I can't see them offering real offroad options. They just don't have the financial motivation to offer this stuff.

Tho they seem very willing to adopt easy upgrades to the production line if a customer can convince them of its value.

Any chance you can go to TN and argue our case?

BtW this is off topic but I think you will appreciate it.

"The above mentioned other factors are cost we incur per unit that we feel adds value, safety and confidence in our product:
RVIA Certification: Look it up. We have 6 unannounced visits a year to insure we are conforming to their standards to be listed by them. They demand ANSI codes be met just like a county or city government requires when building a new home. Electrical components are all UL or equivalent listed. Wire gages meet ANSI specs based on amp load per line etc. Plumbing is all UPC or equivalent certified. Lots of hoops and testing to be RVIA Certified and we pay for all the cost of those six annual visits.
NATM Certification- They visit twice a year and insure we are in compliance with DOT guidelines concerning DOT approved lighting, proper tire data info for load capacities to mention a couple of areas.
While we would be more than willing to compare our original frame construction against ANY other trailer manufacturer on the market, for the 2016 model we are introducing a newly designed A- Frame construction with a custom, extruded for us only structural piece of aluminum. More details to come. It is intended to with stand a much more rugged use over 20 years of boon docking while traveling the back roads with the 18 inch ground to frame clearance. This has been designed and 3rd party tested to wrap up every aspect of our build process to back up the “Legacy” aspect of the trailer."

http://www.fiberglassrv.com/forums/f51/2016-oliver-trailers-base-price-increase-71722-2.html#post550061

It looks as if they are beefing up the frame. It sure makes sense to me to refine the suspension too.... What do you think of the frame comment?

John Davies
Spokane WA

 

[OCD Overland]

If we decide to order, I'm definitely going to push for some of these things. I was hoping you could soften them up for me. I get the impression that now that they have certifications on their trailers that they're limited in what they can do without getting them recertified. And apparently the groups that do the certifications make random visits and if they see a trailer being built to a different spec, they start asking questions. At least that's what I think has happened. Also the guy who gave us the factory tour mentioned that the owner would like to stop paying people to buy their trailers, lol. Get them cheap while you can, I guess - I worry that they're going to be priced like air streams before long. But unlike air streams, they might actually be worth that.

We're about three hours from their factory, so they may find me looking over their shoulder more than they want.

But we're still debating the Kimberlies...

 

[thethePete]

As mentioned elsewhere, a pump is pretty overkill. Rally cars etc use a scoop on the roof, above the dust, to create positive pressure while moving. I would think that using a scoop, possibly with accomodations for a drop in car air filter, or cabin air filter, would be more than adequate. No need to Rube Goldberg the heck out of this one. The system works well passively, I would shoot for that first.

Otherwise, I would recommend using 1 or 2 computer fans. 120mm fans, they're designed to be run continuously, they're fairly compact for the amount of air they can move, and their draw is VERY minimal. Plus they're 12V already. That would be what I would be using as my first effort, a simple filtratoin system in front of them would be easy to create, and you're done. Make a rectangle hole with channels to accept a slide in filter (small panel filter from a car, home furnace filter, cabin air filter, something like that), and done. Cabin air filters are expensive, but you want something that doesn't offer much restriction to the fans, an engine air filter might be too restrictive for anything but a high-draw fan.

 

[John E Davies]

If we decide to order, I'm definitely going to push for some of these things. I was hoping you could soften them up for me. I get the impression that now that they have certifications on their trailers that they're limited in what they can do without getting them recertified. And apparently the groups that do the certifications make random visits and if they see a trailer being built to a different spec, they start asking questions. At least that's what I think has happened. Also the guy who gave us the factory tour mentioned that he'd gotten a directive from the owner to stop paying people to buy their trailers, lol. Get them cheap while you can - I suspect they're going to be priced like air streams before long.

We're about three hours from their factory, so they may find me looking over their shoulder more than they want.

But it still debating the Kimberlies...

Cool, I am 30 hrs away by road..... please look at the previous post, I added more info after you posted this one. Did you see my frame comment?

JD

 

[OCD Overland]

It's interesting. Robert did point to the tongue of one of the frames and said that it was a custom extrusion, so it could be that the frame in the photos I posted is the new one. On the other hand, he also showed us where they were building a new rig for frame making. So maybe what we saw was sort of an in between version.

I think the frame seems super strong, personally. The way they designed the A-frame section at the front, with staggered joints means that you don't have any moment force acting along multiple welds. I think their 'legacy' philosophy is genuine - they're definitely 50 year trailers, if not many more.