A/C odor?

This is currently being discussed in another thread. Dealers and AC service shops have stuff they spray into the evaporator that fixes the problem.

I have suggested running the heater at full speed and high temp for 5-10 minutes. This often will, at least temporarily, eliminate the problem.

Are you sure there's not a ripe sweat sock under the seat? :wink:

 

Steve:

Every A/C evaporator will *eventually* give off a funky smell: home, commercial, or automotive. The interval can be fairly short (Weeks to a few months) in a very humid climate, longer in a hot dry climate.

The reason is fairly simple: When the evaporator is ice cold, the moisture in the environment condenses out the entire evaporator is covered in condensation. You can really notice this on large commercial chillers and evaporator coils.

That moisture dribbles down and collects in the drain pan, which is what makes that puddle under your car when the A/C is on.

Of course, all that moisture and darkness is also the perfect breeding ground for mold and mildew. And when those disgusting things breed, they STINK. Get enough of that stuff growing and you will even have health problems.

Do you also drive on a lot of dusty roads or in an agricultural area? Park the car under a tree where leaves, needles, sap, etc can collect in the HVAC intake? If yes, you may have already introduced plenty of "food" and raw spores to get some real funky mold/mildew breeding.

The only guaranteed way to cure the funk is to clean the evaporator. The old-fashioned way that works 100% but can only be done with the evaporator removed is to use ammonia or bleach. You then have to rinse with plenty of water to get rid of the ammonia or bleach smell.

Never, EVER try to mix ammonia and bleach. Unless you're some sort of Junior Chemistry Evil Genius nut.

Yes, there are products just designed to clean evaporator coils. I have experience with some of them on industrial chillers and large control room evaporator coils. I'm most familiar with NuCalgon products:

http://www.nucalgon.com

I've used their Cal-Brite with excellent results but that is fairly nasty commercial stuff: PVC gloves and a respirator please. Lot's of surfactants and ammonium bifluoride.

I've also used their EVAP-Foam with good results, but it's nowhere near as strong as their Cal-Brite. They claim the EVAP-Foam is no rinse.

If you have a high speed internet connection, please read the following NuCalgon pdf's:

http://ftp.nucalgon.com/ftp/prodlit/3-917.pdf

http://ftp.nucalgon.com/ftp/prodlit/3-34.pdf

These pdf's explain how to properly clean evaporator coils and condenser coils. They have some relevance to automotive applications:

http://ftp.nucalgon.com/ftp/prodlit/3-125.pdf

http://ftp.nucalgon.com/ftp/prodlit/3-116.pdf

I'm not sure how easy the evaporator is to access on the Prius. Somebody - more than likely a Prius tech or maybe you if it's easy to get to - will have to clean the evaporator.

Sorry if this isn't the easy answer you were expecting. Ask your Toyota dealer what they recommend, maybe they have the NuCalgon or a rebranded product.

Otherwise ask around at large commercial HVAC contractors. Good luck.

Jay