How to block the outside air vent

[shadetreemechanic]

Due to polluted air coming into the cabin though the air vents (especially when driving behind a crap diesel) I've been thinking how to block up my outside air vent, shown below.

I thought about trying to find a pollen filter similar to what can be made to fit to VT onwards (VE onwards come with one from factory) but this seems all too hard so now I just wanna find the best way to block up the whole vent so air can't come in. I run my AC on recirculate anyway so I don't need fresh air and I reckon there won't be any issue running low on oxygen or anything like that....

So what do you guys reckon? Has anyone done this before, and how did you do it?

 

[one_and_only2004]

Silicon a bit of rubber mat over it - that or expander foam the whole thing.

 

[_R_J_K_]

Nah, don't use the expander foam. You want it to be easily removable in case you find out you actually need that hole open. The expander foam will trap moisture too.

 

[ephect]

Can't U switch the dial on the console?

 

[shadetreemechanic]

Can't U switch the dial on the console?

Edit: actually you're right the fresh air vent is well shut when on recirculate, i just ripped out the glove box this arvo and had a look. Pollution must be coming in through the door seals then...

I'm gonna leave it as is for now until i fabricate some sort of filter housing for the outside vent. Then i think i'll add a proper HEPA filter so i can then use the vents on fresh to build up positive cabin pressure which should stop air leaking in past the seals.

Here's some very recent research into this issue if anyone cares http://www.sciencedaily.com/releases/2014/02/140219113426.htm