Stinky A/C in hot, humid climate? I might have found a solution that I'm currently testing with positive results.

[dcdttu]

My SOP is recirc off unless there is something really stinky outside. There are a number of comments on other TMC threads on this topic that make the argument that recirc is the way to go, as recirc off continuously brings in more humid air, while recirc on is maintaining the the dry environment. It certainly does not sound insane, but I'm not an HVAC engineer. Are the any educated opinions out there on this line of thinking?

Not educated, but I don't think it matters to be honest. My car opens the vent and runs fresh air through the system after getting out of the car if the A/C was used. So, whether you are fresh or recirc while driving, it's gonna be fresh when you get out. All Model 3's (and maybe Y's?) do this.

The stinky A/C problem was "fixed" with a software update that causes the car to turn on fresh air for a while after being driven. This can stay on upwards of an hour after you exit the car. I am sure it helps, but in my case it's not enough.

 

[Blacktes24]

Absolutely, here you go. It seems logical to me that making sure no organic growth happens between the filter and coils.

Advanced Carbon Activated Filters

saving for later...

 

[stopcrazypp]

My SOP is recirc off unless there is something really stinky outside. There are a number of comments on other TMC threads on this topic that make the argument that recirc is the way to go, as recirc off continuously brings in more humid air, while recirc on is maintaining the the dry environment. It certainly does not sound insane, but I'm not an HVAC engineer. Are the any educated opinions out there on this line of thinking?

I guess the theory is that if the air/HVAC system already has mold/mildew spores (or the smell of it) in it, although recirc removes moisture, it'll be continuously recycling that contaminated air and either depositing the contaminants on the filter/HVAC tunnel or pushing it into the cabin. When the AC is off (or just starting), the smell then is amplified, especially when the filter is saturated. I guess that explains why a new filter gives some temporary relief that for some people doesn't last very long before they have to replace the filter.

With recirc off, although the air coming in may be more humid, it is fresh air that can serve to dilute any contaminants. That may balance out any possible contribution to mold/mildew growth from higher humidity.

This is hugely anecdotal, but from the forums, I have seen people reporting they have an improvement with recirculation off (or at least leaving on auto), while I have not seen people reporting an improvement with recirculation on (in fact the opposite, some say it is made worse by that). That suggests manual recirculation does not help the situation, but rather may make things worse.