I live in Florida and have mold allergies. Multiple times my 2008 Sienna van has a bad AC smell develop which makes me cough my head off. The dealer has cleaned the evaporator and ducts and the problem gets better but returns.

I read on this site that I should not use MAX and the recycle air setting so much as it prevents fresh air from drying out the evaporator and tubing. I also read I should let the system run fresh air without AC for a few minutes before turning off engine.

My old Volvo wagon had a fan motor that came on for a while after the engine stopped. I thought it was a malfunction but the dealer said it was to dry out the AC.

All that understood - when it comes time to buy a new car:

Which car manufacturers, other than Volvo, have added some kind of mold prevention to the AC system?

  • 10
    What Volvo model did you have? Some older Volvos (e.g., the 900 series) had engine cooling fans that would sometimes continue to run for a few minutes, but I'm not aware of any feature to dry out the A/C. Nov 27, 2011 at 16:34
  • 1
    I'd agree with William, most cars run the radiator fan after the car is turned off if the coolant is too hot. I suppose it is possible that the Volvo had some sort of alternate fan on it, but I've never heard of that. Did the dealer replace the cabin filter on the Sienna?
    – Harv
    Dec 1, 2011 at 21:34

1 Answer 1


In my humble opinion, the mold could have gotten into the ducts, and you have 2 options:

  1. New Car
  2. New Ducts

They can clean the evaporator and other parts, but if its in the ducts it might keep coming back if they don't get rid of it all.

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