White dust from vents?!

[JonGTD]

Good afternoon guys, new here and in search of some help!

I did a quick search but couldn't seem to find anything relevant, just wondered if anyone else has experienced the problem I have...

I own a mk7 GTD, have had it for 4 years (it's a 64 plate). About 2 years ago I noticed that when I had the AC on full blast in the summer, there were small white dust like particles blowing out of the vents. Further experimenting showed that it happens when on max heat too, in fact at any temperature. I have searched for answers for a long time and have only found a few helpful bits of material online, so I just wondered if anyone here has experienced this or knows any more about it?

From my research it could be a problem with the AC evaporator, as shown in this video

https://youtu.be/JiU_OP2XLVY

Any more knowledge or help would be much appreciated!

Thanks

[fredgroves]

Seems very likely that's the cause doesn't it.

That's got be some sort of surface corrosion on that part hasn't it? But caused by what?

[JonGTD]

I have no idea, I made some enquiries with my local VW garage and they were not very convincing but made out they had heard of this problem and it was an expensive job to change the evaporator, was just hoping before I take any action I could hear from someone who had experienced a similar problem!

[fredgroves]

Googling around it seems its a common thing across air conditioning in general but why I've never seen anyone say about it on here is weird.

[Ryan90GTI]

When was the last time the pollen filter was replaced? Could be worth trying that as a cheap first port of call.

[JonGTD]

I did the pollen filter when I first experienced this problem, didnt help 

[bgbazz]

I've seen this once before, on one of my cars. I had used one of those aircon refresh/clean spray applications to get rid of a stale smell in the cabin. It seemed to work well and made a big difference thereafter.

The whitish dusty stuff appeared about a week later but gradually seemed to get better without me doing anything about it.

My two bobs worth.