early air con

Just seeing if anyone has a diagram or photo of the early air conditioning unit that would sit on the outside of the drivers door, I think it had water in it and the air would cool as it pass through and in to the cab. Its a circle with an hollow centre. It would be on a split bus I think. Its a long shot I think, but worth a shot.

 

Its somtimes called a swamp cooler

 

That's the ticket lol swamp cooler.

 

https://www.google.co.uk/search?q=swamp cooler vw bay&espv=210&es_sm=93&source=lnms&tbm=isch&sa=X&ei=KGwoU-_UH83M0AWR44DQAQ&ved=0CAcQ_AUoAQ&biw=1290&bih=683

 

I just googled homemade car swamp cooler and loads of stuff and plans comes up