Quote:
Originally Posted by yousefnjr
Yep, as another poster mentioned you’re supposed to run fresh air or no AC for a few minutes to help dry it out, but I don’t have that kind of discipline lol. Kind of a farmy area around me, so it’s either recirc and a little foot smell or fresh cow shit air 
I’ll take a look a little later, maybe that’s easier to get to than under the car. I did buy that same cleaner. Should be here in a couple days. I’ll update the thread with how this turns out. |
Copy pasting a reply I made years ago:
Quote:
Originally Posted by jmg
This can actually promote mold and mildew growth which increases the chances of bad smelly AC if you do it too soon before you turn off your car. When you blow non-conditioned air through the vents, you are introducing relatively humid air to the interior of the air ducts. The ducts are still relatively cold from the previous use of air conditioning. As the ducts warm, they collect moisture from the warmer, humid air on the inside and condensation forms on the interior. If you leave the air on long enough, it might cause the condensation to evaporate, but if you turn the car off, the condensation remains, and you can introduce mold and mildew. Note that it takes MUCH MUCH longer for the condensation to evaporate than it did to form. You would have to turn your AC off a very long time for you to ensure that it all evaporates.
Alternatively, if you leave the AC on before you turn off the car, the air in the ducts are relatively low humidity. That means when the ducts start to get warmer, there is significantly less condensation on the inside of the ducts because the air is conditioned aka dry. Note that the condensation on the exterior of the ducts is less of a problem because even if mold and mildew grow on the exterior of the duct, our HVAC air runs through the interior, thus no smell.
So, if you had to chose between turning your AC off or leaving it on... it's almost always better to just leave it on and leave it on always. Remember, moisture is bad, and AC is basically a dehumidifier.
|
In short: there is very little moisture in your AC ducts since AC is a dehumidifier.