Dust Proofing a Caravan

Never done that but have put a push up pressure hatch in the roof of a full van. It seemed to work but it would probably be a bit difficult finding a spot up high enough above the dust in a pop top.

We have the windsor rapid offroad model and have it fitted with a pressure hatch which is about 15-20 cm wide and pops up into the airflow over the roof when opened to pressurise the inside of the van and force air out the door vent. We did the Oonadatta track and a few thousand km dirt road without any significant dust egress. The rear bed end gets a bit in but the rapid is all sealled so it stays on the outside of the canvas until you get home to clean it anyway so no harm. Seen all sorts of additional sealing but the standard windsor foam stuck around the bed end seals seems to work fine.
How much dirt road driving do you intend to do??

When you drag something as big as a caravan along at reasonable speeds you will create a vacuum inside the van. The causes, and there are many in most vans, are the door vent, the fridge vent, the numerous ports for cabling and piping plus all of the smaller holes in the sheeting and flooring that were missed in the factory to mention a few. The best way to avoid the dust is stay off of the dusty roads.....but that is where the best camping spots are!!! You have to create a positive air pressure inside the van, an electric fan would have to move a lot of air to create this positive pressure. The scupper vent, that is an openable vent on the roof, above the dust line, is the simplest and cheapest remedy. When you have one fitted, ensure that the cuts into the roofing sheets are fully sealed against water ingress as you would with a window fit.

Don't know if I should call you Poppy or Kevin, I try Kevin. If you install a 12v fan to create pressure inside the van, that mean you will have air loss through the myriad of exit points, that then means you have air entry to equalise the loss. if you don't control the entry point you will have air rushing in from all sorts of places bringing dust with it. If you control the entry point with a pressure hatch on the roof you will probably find you don't need the fan. Carts

I see that no one has mentioned what is commonly overlooked as a dust inhaler in caravans and that is the air conditioner fitted to the roof. Some of the Dometic ones have drain holes from the evaporator that drain water over the top of the caravan.

If you have one of those, I believe you can reduce the drain holes in volume capacity tremendously and stop the way air conditioners suck dust into the inside. I have two of the holes blocked completely and the other two blocked by about 40%

If you take care of that sort of dust ingress a decent filtered air intake can do the rest. Dometic don't seem to recognise the problem. The B1900 certainly has these drains and they just look like two corrugations down the lower part on top of your caravan. You can poke a little finger into each one from underneath.

We have found that a piece of foam rubber held between the door and screen door covering the bottom vent keeps a lot of dust out of that area. It doesn't block all the air so you still have a gas vent (and the gas is switched off anyway while travelling) and it keeps dust out. Our foam is about 2cm thick and we got it from an upholsterer but no doubt Clark Rubber or similar places would have a good fine foam. You can also use it to protect the space behind the fridge while travelling - we checked with our manufacturer and were told that it won't do any harm to cover the lower vent while running the fridge on 12v. You just have to remember to remove it when you stop. Lynne

G'day Poppy Kevin
I haven't personally done or seen this, but I had an interesting conversation with a bloke that fitted a heater/air con fan to his ute canopy. That's the fan from under the dash.
He started with computer type fans and quickly found the volume of air was to low.
With the heater fan he found that the dust was not only kept out but was actually blown away from around the door seals.
I have forgotten most of the conversation, but he did mention his mate had fitted 2 heater fans to something bigger to keep the dust out. Can't remember what it was now.
This bloke had one of a fibreglass canopies that you see on full size 2 door trade utes & it was mounted on a cruiser cab chassis. When we met him at Big Red he had gone East to West across the Simpson, down the Great Central, up the Canning, down the Tanami & West to East across the Simpson & had no dust in the back. So I would say from that that it might work.
I have looked at this situation for a long time & I reckon fitting a filter would be the go if not too difficult. This bloke never had a filter but travelled on his own.
Keeping the rain out would be another issue to consider as well .
Good luck & let us know how it goes in the future.