I think this has been addressed before but unfortunately, I can't find the thread.

I'm concerned about the A/C being used often and then accumulating that horrible smell if you don't "air it out" regularly. Apparently this is to get rid of bacteria formed inside the vents. Can someone explain to me how to "air out" the vents?

On the other side of the spectrum, in colder months when you wouldn't use the A/C, I heard that you should turn on the A/C say, once a week at full blast for about 5 minutes. This apparently is good for the pipes as the A/C releases some lubricants into the pipes. Again, you're supposed to "air out" the vents after this process to stop the bacteria forming. Can anyone validate this also? Thanks.

 

The Lexus A/C evaporator core is so dense and complex it retains water like a sponge. the 92 LS evaporator has over 10,000 sq inches of surface area and will retain over a pint of water for more than 24 hours setting in the open in a two bay garage.

When the average temperature is above about 50F (or say in a closed garage) the damp and dark environment of the A/C plenum is a perfect breeding ground for mold, possibly even toxic mold.

The best way I have found is to be sure and open the sunroof and/or windows (slightly if CIH {cat in house}) during the times the vehicle is not in use.

Personally I remove the A/C compressor clutch relay during the winter months here in the pacific northwest in my 01 RX that way it doesn't even run the A/C in defog(demist) without my knowledge or control.

Some people advise that you turn off the A/C a few minutes before arriving home to give the system time to dry out but I find this advice to be useless.

The evaporator core operating temperature is always above 32F and generally below 35F, on an extremely hot day it might take only minutes to begin evaporating the thin film of moisture on it surfaces but that process is likely to take up to an hour.

There is an aftermarket device that might help:

http://www.airsept.com/eed.html

Good luck.

 

...and now for the reply you care to read Well, what I do myself is never worry about it, really. But if you want I would suggest turning the a/c about 5 minutes or so prior to shutting off the vehicle. When you are on your way home just let the fan run with vented air for a while w/o the a/c to dry out the vents. That's my shadetree solution

-nick

 

Thanks Nick. Actually, thanks to both of you for your replies. I'll use the "switch off A/C 5 minutes prior to arriving home" method and hope that works. I don't have the horrid smell yet but did in my previous car so I just want to avoid it in my beautiful RX300.

 

But GM is actually installing the linked device "EED" for customer who complain of the musty smell having developed in their vehicles.

I'm not suggesting that anyone actually purchase one, but the text in the article does a very good job of detailing the causative factors and their "cure" methodology.

 

I just talked with an automotive A/C specialist who says many cars will take more than 5 minutes to use up the liquid refrigerant already in the system pressure side after the A/C compressor is shut down, especially those with accumulators.