Wet towel (mildew) smell coming out of air conditioner

Cold and damp environments like air conditioning ducts are ideal for nasty-smelling organisms. It helps if you run the heat after the cold, to dry out the condensation and prevent the formation of moulds and mildew. Once they're in there, disinfectants or bleach will kill them off, but the areas are hard to get at. You could try a can of Lysol sprayed into the intake ducts with the system on full blast for awhile, and it wouldn't hurt to check the cabin air filter. The dealer's $100 service doesn't sound like it includes disassembly of the affected components, but you could ask.

 

It's just condensate from the AC, that sits and doesn't evaporate. Run the heater and it should evaporate no problem. I would get the smell intermittantly when I lived in Los Angeles. It usually went away after about 15 minutes of the heater running.

 

<div class='quotetop'>QUOTE(michael_prius @ Oct 9 2007, 08:08 PM) [snapback]523366[/snapback]</div>

 

Do you park on a hill and has it rained recently? I used to have a camper van, and if I parked going uphill when it rained, the water was able to back in through the A/C ducts and cause this type of problem. If I parked nose downhill the water could not enter.

 

<div class='quotetop'>QUOTE(michael_prius @ Oct 9 2007, 09:08 PM) [snapback]523366[/snapback]</div>

Got the same problem with my 1500 mile 07. Yes 1500 miles. Its a design problem for sure. Really its the only problem I have not been able to fix by someone's suggestion here. In Florida you can't drive anywhere without the air on. In fact today 10-9 it was 89. Putting on the heater trick before you shut it off for the day is not really an option as it has been 95 outside for the last month. Should you really have to sit in the car with the heat on for a while every day before you put it away? Or leave it running with the heat on...in the dead of Florida summer? Its a brand new car! How many $ 25K cars have you had to do that with in your lifetime? Me? None. But I tried it and it does not work. Smell was back the next day. In the morning upon start up I now drive for a few miles with the windows down...sweating.... and the air on till the smell goes away or actually till the inside condenser is wet and the mold is soaked and can no longer emit the smell. Great for gas mileage. But I have no choice. It stinks that bad. Its a real problem. I don't smoke...car is garaged every night...garaged at work all day...always clean and detailed inside. I can't remember even being caught in the rain.The car is mint. But if I smell the vents now with the car off the vents smell moldy. Very moldy. The car is brand new.
Kinda depressing to have that horrid smell. Not going to waste my whole day to have the dealer spray Fridgie Fresh in the vents and it smells like a hospital for a day. Its not usual for a car to have that smell so prominently so new. Have owned many cars here both new and used and not had that smell so bad so new. Something must be different or unique to Prius inside condensers. Not draining correctly maybe although I notice it drains pretty good based on the puddles on my garage floor. But maybe not draining completely? Or not vented right. Why does mold grow so intense on these condensers. It doesn't grow that bad on home AC condensers or other car's? Type of metal used on the condenser itself that promotes mold growth? Some kind of wacky alloy instead of aluminum like everyone else? I Wish Toyota could come up with a fix because if they did I would not have one complaint with this car. I love this car. Toyota...please HELP!!!

 

Check there are no leaves in the plenum chamber in front of the windscreen, where the air gets into the vent system from outside.

There is a drain that comes through the fire wall, it is a black rubber pipe which is pinched on the end to prevent air getting in but allows water out, make sure it isn't blocked. It should be checked during a service. You can find it by getting under the car with the airconditioner on, water will drip from it. Use a piece of coat hanger wire to ensure it's clear but dont damage it.

Remove the cabin air filter (replace the slide it lives in) then with the fan on low airconditioner on and set to recirculate spray a disinfectant type spray (Glen 20 surface spray or Oust) into the vent under the dash, no need to pump a lot in just a few 3 second squirts with the air conditioner on to make the spay condense on the cooling coils then shut down the fan. Replace the cabin air filter in the slide, use a new filter if it looks dirty. Do this before you leave the car over night to give the spray time to do it's work. This should fix the smell.

The heater will not heat the airconditioner coils as it is down stream in the system in all cars I know of, but running the fan with warm air from outside or the cabin will dry the coils. It is a good idea to turn off the airconditioner leaving the fan on and recirculating for a few minutes before you reach your destionation to allow it to dry out, it also reduces fuel consumption without discomfort as the cabin shouldn't heat that quickly.

 

<div class='quotetop'>QUOTE(Drifty'sDad @ Oct 10 2007, 01:12 AM) [snapback]523475[/snapback]</div>

I have covered this before and would like you to reference the following thread.

http://priuschat.com/index.php?showtopic=38755

I know I'm being picky, but the source of the odor is the evaporator coil, not the condenser which is mounted in front of the radiator.

I have asked around various HVAC outfits if they had a clue why a Prius A/C would stink. Mine finally started to give off a smell this July when we had a bout of incredibly hot and humid weather. The A/C at my hobby farm also started to give off a funk

An older guy who owns an HVAC outfit east of Winnipeg in a town called Steinbach finally had a plausible theory for me, which neatly explains why the A/C at my hobby farm also is more prone to stink

The Prius A/C compressor is electric variable speed. This is completely unlike a conventional automotive A/C compressor, which uses an electric clutch to engage and disengage the compressor. Rather than cycle the compressor on and off, giving the e-coil a chance to dry off, the Prius A/C is almost always on. That is actually much more efficient. However, the e-coil is always cold and saturated with moisture

At my hobby farm, I have a Bryant Evolution system: efficient condensing gas furnace with variable speed fan, a two speed outdoor A/C unit, and a control network with outdoor temp sensor to properly stage the operation of the heating and cooling cycles.

With my Bryant system, in cooling mode the A/C unit operates almost all of the time in low speed compressor operation. The A/C is sized according to the high speed capacity, so when it can operate in low speed most of the time, it's a lot more efficient. A PID control loop is used to stage the cooling - or heating - based on outdoor temp, indoor temp, and setpoint.

As it can operate almost 90% of the time at the low speed, the variable furnace fan can run slower too. The slower airflow across the e-coil allows much more moisture to be condensed from the house air, anywhere from 3-10 times more than a conventional A/C. The house is much drier in humid weather. However, the longer duty time results in the e-coil almost always saturated with condensed moisture.

The theory is, the longer duty times with the e-coil always saturated with moisture, really helps grow mold and mildew that would otherwise not be a problem. All it takes is one invisible spore, and the right conditions, to have a stinky problem

The problem can be cured, but you require the correct product to erradicate the source, not just cover it up with another smell. I've had good luck with NuCalgon Evap-Fresh, but sometimes you have to do two applications.

NuCalgon Bio-Fresh CD is much stronger and will usually work in one application. I recommend the Evap-Fresh as it doesn't have a sharp, stinging odor that lingers. Within an hour, you can't smell it.

I hope this helps. Feel free to PM me if you need more detailed instructions

<div class='quotetop'>QUOTE(patsparks @ Oct 10 2007, 03:27 AM) [snapback]523502[/snapback]</div>

That is how I sprayed the Evap-Fresh into the car e-coil. However, the smell returned after a couple of days, so I had to repeat. That appeared to erradicate the odor

I would like to know the location of the heater core and e-coil in relation to the exterior of the case. It would be easier - and more effective - to drill a small hole into the case at a location that directly faces the e-coil. One could then saturate the e-coil with the disinfectant, then use a press in plug to cover the hole.

There are companies here that offer to clean your house ductwork. Then drill approx 1 inch holes every 4-10 ft in the ductwork, then blast in compressed air while running a strong vacuum attached to the other end. When finished, they press in plastic plugs

Of course, I would be very careful attempting to drill the case of any automotive A/C. Get the location wrong - or actually drill into the e-coil - and you're looking at a very expensive repair bill

 

Thank you Patsparks and Jayman.....

Patsparks: Yes the condensate is draining quite nicely as water is pouring out pretty good as it should.

Jayman: Thanks for that very informative article. I think your right on the money there with a "maintenance hole" drilled in the e-coil case. Giving access to the e-coil to be able to spray some mold killer on the e-coil itself. That would fix my issue as I would gladly spray something in there once every couple of weeks. In Florida the ac is always on in the car. Its getting quite stinky. I can't imagine how bad its going to get as the car is only 2 months old. Its too bad because I thought I had found auto nirvana but like most of my plans it's not to be.
I clean my house air handler about every 2 years too(we don't smoke & change AF's every month so it stays pretty good). Clean out the e-coil real good. Its amazing how many people don't understand or even know you have to clean out the e-coil on your house unit . Its usually people with non stop sinus infections or resp. problems and stink houses.
Now we have to figure out where to drill that hole! This weekend I'm going to look around under the dash. Drilling a hole in that air box is dicey business but I think your on the right track. I'd like to find a totaled Prius in the bone yard and see how the air box is set up under the dash. In the meantime I will try the spray the filter trick. Thanks alot!

 

<div class='quotetop'>QUOTE(Drifty'sDad @ Oct 10 2007, 09:56 PM) [snapback]523981[/snapback]</div>

That's a great idea, to find a wrecked Prius. It's quite possible the salvage yard may even have an intact HVAC unit from a wrecked Prius, so you won't even have to crawl around a wrecked car full of snakes and bugs.

I've had some experience with commercial HVAC - primarily control networks like the icky BACNet that Tony likes so much - so I knew where to use my ziptool to cut the access hole for my home e-coil.

The interesting thing is that the e-coil may look spotless, but harbor an invisible and stinky mildew/mold problem.

I hope you find a solution. Just partially misting the e-coil will only "solve" the problem for a short time, as you won't be able to eradicate all of the source spores

 

<div class='quotetop'>QUOTE(jayman @ Oct 11 2007, 12:01 AM) [snapback]524006[/snapback]</div>

Thanks again Jayman....anyone without the problem reading this must think were nuts but it sucks to have a brand new car stink so bad. Especially a car that I'm really really happy with in all other regards. There's alot of boneyards in my town...I think I'll make some calls next time I'm at work and its slow. A busted out air box from a Prius would be sweet to inspect. I'll get back.

 

<div class='quotetop'>QUOTE(Drifty'sDad @ Oct 11 2007, 08:54 PM) [snapback]524356[/snapback]</div>

Until a problem happens to the individual, they rarely believe it exists. For example, they hyper sensitive traction control on my Prius. Those of us with that issue are usually called into question, especially our winter driving skills, (Sarcasm Mode ON) as apparently there are Prius cars out there that can charge through 10 ft drifts and drive 87 MPH on glare ice with bald summer tires. (Sarcasm Mode OFF)

 

The way to fix this is to check the evaporator drain hose, it's probably clogged. I've seen spiders crawl up in there, rustproofing, etc can all clog it.

Just spray compressed air up in there to clear it (like from an air compressor) then run the fan on fresh, full blast. Spray a full tube of Ozium into the air intake up by the windshield, or pull out the cabin air filter and spray it in there.

I've done this dozens of times to various cars, and never had a complaint that it didn't work. The ozium smell will go away after a while.

Nate

 

<div class='quotetop'>QUOTE(naterprius @ Oct 12 2007, 03:01 PM) [snapback]524755[/snapback]</div>

Thank you NaterPrius but its draining quite nicely. Plus I would think if it was clogged it would find another way to drain like on the carpeted floor which is a common problem on may older cars. No I suspect its a system problem as I only have 1500 miles and the car is mint in all respects. Have seen many other posts having the same problem. I'm somewhat more sensitive to it than the average bear as have bad allergies esp. to mold. Many years of allergy shots 1 in each arm once a week for years! Much better but can smell mold where no one else can but in this instance its not in my head....voices maybe..but not this smell. BUT...I'm willing to try anything. Thank you!

 

I found Ozium on eBay and just bought some but cannot find any Nucalgon products that Jayman suggested.
There's a HVAC wholesale joint open to the public I will try Monday. I'm going to check on the draining pipe this weekend.Thanks all.

 

Always glad to try and help.

 

<div class='quotetop'>QUOTE(Drifty'sDad @ Oct 12 2007, 07:59 PM) [snapback]524926[/snapback]</div>

NuCalgon has their site at

http://www.nucalgon.com

Clicking on "Where to Buy" and chosing Florida, returns 11 distributers. A Yahoo or Google of "nucalgon products" also returns many hits

Some commercial HVAC outfits may be picky about selling to the public. The products are safe if used as directed.

Whatever you do, don't mix up laundry bleach and spray it in. Although the laundry bleach will absolutely erradicate the source of the stench, it will also attack the copper tubing in the e-coil.

 

I get that here too, I used to think it was me..... :blink: no serisously, every car I've had since I've been in Cali it's the same smell. So I thought I was stinkin' it up from the gym or ....whatever , I've realized it's just the moisture in the vents. although I have to say there is no moisture anywhere else in so cal (well except last night it rained, :lol: )

I agree though you should run the heat for a bit, seems like that would do the trick.