Reducing Dust

It hasn't really been a issue with any vehicle l have owned for many years , windows open of coarse will let dust in .
What vehicle do you have that lets dust in .

Hi Tracy

Aircon on recycle, not fresh with the windows closed.

Air will come in via a cabin filter and leave via some form of clapper valve to release air pressure that builds up.

You will always get a bit of dust film, but I find the above keeps it out of pour vehicles.

Cheers

Anthony

I think it depends if there is other traffic, if so and the air has dust in it, then vent closed AC on.

If no other traffic I have the vent on fresh air and the AC on, works for me.

Yep, last Simmo trip had the air cond on high, windows shut, and no problems, not even a little dust on the dash like there has been on other trips across.

Of course seals undamaged is a must.

Pressurising the back of my ute tub / canopy area is pretty easy with the ARB optional vent fitted, pressurises the back and I only get about a cm of dust around the edges of the completley open tailgate gaps.

With the Prado wagon a pressurising vent might not be practical.
Of course having the cabin pressurised with the air cond is probably the best bet for the back door/s too.

In situations where the air cond is not needed, you can leave the air cond switched off and just use fan on high, of dial down the temp to get air cond temp right for conditions.

Hi Tracey

I'm not a supporter of the pressurization theory , there simply isn't enough capacity of fan/vents to pressurize.

I suspect the cause will be that doors seals are not quite sealing all the way round.
And generally the big rear door is the problem as it moves around momentarily letting in little bursts of outside when you go over bumps/ corrugations.

If you look at a picture of airflow over roof it curls down massively as it exits back roofline and impacks dust laden air onto rear door. For this reason you can get aftermarket dust deflectors for rear door.

Of course the dust laden air will only get in past bad seals.

To test seals get a piece of paper 50-100mm wide and close door onto it, then gently tug at the paper and if it slips out easily yhen there is a seal issue at that point.

Often the rear door can be adjusted up to lessen effect of seals.

General dust will come in at a lower level via front of car if fans are turned higher , and recirculate reduces dust from this means.

Had problems in my 80 series on the last trip. Dust was getting in through two grommets at the back which were dislodged and also through the rear vents. Replaced the grommets and will try taping up the vents.
Now just need to go away again to see if the problem is solved.

What works for me is windows up and run the air cond on fresh to pressurise the cabin. Of course it helps to have good seals and all the grommets in the right places and not distrurbed by towbar installers and the like.
The only way to pressurise is to have fresh air coming in. Doesn't happen on recirc.

On my 200series the air cond defaults to recirc when you first turn the air cond on, so I have to manually change it to fresh.

Find where the cabin vents are in the back end of the vehicle and make sure the little rubber flaps are actually still doing their job. If they get bent or stuck in the cage that holds them together, then they will let dust in. I'm not sure where they are on a Prado, but in behind the back wheel in the bumper is a popular choice..... right where the dust is worst.

Blocking off some of the vent with tape will allow the pressure to be slightly higher in the cabin and stop dust being sucked back in through the vent and seals as well as reduce the vent flaps ability to flap and suck dust if there is turbulence from winding down a window.


This bloke went all in, but it will give you an idea of what you are looking for:
http://www.livingoverland.com/2013/04/controlling-dust.html

I find it works best on my Prado to have plenty of outside air coming in and hit recirculate when a vehicle is coming the other way to avoid his dust. No issues for me this way.

When on recirc, only a small portion of the air is brought from outside, therefore not much pressurization
On fresh then whole fan volume - significant - does pressurize cabin and helps reduce air and dust being sucked in around seals. Just try to close a door softly with fans on full and you will see the effect. Lower a window a little and try again.
In saying that some vehicles arent as well sealed as others.
I have seen some tape up exit vents (often near rear side windows) to increase pressure on seals in really dusty conditions. Works but reduces air volumes and therefore cooling on fresh.

Only time this doesnt work too well is if there is dust in air outside and your going to get dust in no matter what. Just avoid it is all can be done.
Stuffed seals, poorly sealing doors etc all leak this pressurized air and reduce the effectiveness

Not that many vehicles in AU spec have air con filters fitted and they arent designed to stop much dust, its too small. Often small in size and processing heaps of air. When clogged the air con doesnt work too well AND lots of dust comes in through lack of presurization.
Stinking air con systems from humid conditions, dirt, sweat, recirc smells is common, they sell stuff to clean them out by spraying into incoming vent.

There are for sure low pressure places on vehicles, around rear door is a good one. Dust can sit around seal and suck or fall in as door opened later on.
Rear dust deflectors do help with this issue

If you want to see if your cabin is pressurised then you can make yourself a simple manometer to measure the pressure differential between the cabin and the outside air.

Purchase about 2m of small diameter clear plastic hose.
Half fill the hose with water.
Put one end of the hose outside of the vehicle. I simply hold it at the top of the door and shut the shut the door on it.
The other end of the hose and remaining hose are now inside of the vehicle.

With the fan off, hold the hose in one hand such that the water level is at the same height in both sides of the hose loop formed.
Now turn the fan on and measure the difference in height between the two.

This works for me and with the cabin air exhaust vents sealed I get about a 5cm height difference on 'Fresh air'.

Regards,
Rob