Mold in car air conditioning systems

[Guest guest]

This topic has come up previously. Interesting article. Here's part of it.

http://www.tirereview.com/?type=art & id=91908

Air conditioning odors typically result from uncontrolled growth of

bacteria and other microorganisms in the evaporator. Research by

independent laboratories has found fungi such as aspergillus,

cladesporium, penicillium and others growing on cooling coils and other

A/C system areas.

How do these microorganisms get there? They

are naturally present in outdoor air, and are drawn into the evaporator

during air conditioner operation.

Moisture also contributes to

A/C odor formation. Most of the moisture that condenses on cold

surfaces inside the system drains harmlessly over time.

However, some moisture continues to cling to coil surfaces after the A/C shuts

down.

Microbial

contaminants in the air combine with this lingering moisture in the

evaporator. The warm, dark and moist conditions in the evaporator

provide an ideal breeding ground for bacteria, mold and mildew to grow

and generate musty odors.

As vehicles were downsized (while also

increasing their glass content), A/C system manufacturers reduced

evaporator size while simultaneously increasing fin count. These

densely packed evaporators trap and hold more moisture.

[Guest guest]

Very interesting article. Thanks . According to this article there is one

product that would last a while--

" One unique antimicrobial product used on mobile air conditioner odor

combines its active ingredient with an acrylic resin that is sprayed

into the evaporator. The acrylic resin dries onto the evaporator coils,

forming a coating that sheds moisture better than uncoated coil

surfaces. The antimicrobial agent remains embedded in the coating,

where it kills or inhibits the growth of any microorganisms that

attempt to settle on the coated surface. Together, the antimicrobial

and acrylic resin coating last in the A/C system for up to three years,

protecting against moisture buildup and the growth of odor-causing

microorganisms. "

Does anyone know what this is that the author is referring to? Or has anyone had

any success in using an non-toxic antimcrobial? Ironically after leaving our

moldy house we lived at a safer place a bit closer to the shore and one of our

cars has gotten funky over time. We've got an air filter in there have had the

dealership use a non-toxic fogger in there that helped for a few months. Have

any of our resident professionals ever had to deal with this?

Many thanks,

Sam

This topic has come up previously. Interesting article. Here's part of

it.

http://www.tirerevi ew.com/?type= art & id=91908

Air conditioning odors typically result from uncontrolled growth of

bacteria and other microorganisms in the evaporator. Research by

independent laboratories has found fungi such as aspergillus,

cladesporium, penicillium and

[Guest guest]

At 03:47 PM 4/29/2009, you wrote:

>Does anyone know what this is that the author is referring to?

Yes. Zinc is one of the anti-microbial used. There are a few others.

Zinc is not the most popular. You found zinc in hand soft soap, and

Consumer Reports says do not use it, as it leads to disease. (Ok,

I overstated their position, but I just use plain soap now as it's

cheaper and does it better per CR.)

> Or has anyone had any success in using an non-toxic antimcrobial?

No reply. I just use soap and warm water. Scrub with elbow

grease. And Vinegar.

Sometimes borax depending on the surface (painted), or real TSP, both are mild

antimicrobials cleaners. But I have had my dash board off just twice now, and

I removed all the ducting, finding the seals were crumbling (ugh to

replace them),

and cleaned the ducts in the kitchen sink. Though the heat exchange unit was

sealed, and too much labor to remove, I did visually see it with flashlight and

mirror and it was looking clean. The source of my smell was something else...

read below. It's so simple to fix.

>Ironically after leaving our moldy house we lived at a safer place a

>bit closer to the shore and one of our cars has gotten funky over

>time. We've got an air filter in there have had the dealership use a

>non-toxic fogger in there that helped for a few months. Have any of

>our resident professionals ever had to deal with this?

Yes. The simple method is every time you hose down your car to wash it

also spray into the external air intake vent grill down into the cavity there,

as it is THAT CAVITY that collects dead leafs, goes moldy, and hurts

the interior duct surfaces. I use lots of soapy water at high speed.

WARNING: DO NOT FLOOD THIS CAVITY. It does have a drain

pipe and you can exceed it's capacity. When this happens,

WATER WILL ENTER THE INTERIOR OF THE CAR, which is

the opposite of what you want. Why is there a drain pipe? Rain water...

Do wash this cavity monthly, and your woes will go away for decades. YMMV

[Guest guest]

Thanks ,

When you say " Zinc " are you talking about a product or the mineral? Wouldn't

washing out the cavity even moderately introduce moisture? One of our cars, a

volvo has wires inside there as well. I wonder if that would be a problem as

well.

Sam

Do wash this cavity monthly, and your woes will go away...

[Guest guest]

At 10:18 AM 5/1/2009, you wrote:

>Thanks ,

You're welcome.

>When you say " Zinc " are you talking about a product or the mineral?

>Wouldn't washing out the cavity even moderately introduce moisture?

The cavity is designed to be washed with rain water.

It has a drain.

There is a remote controlled flap, you can see on some models.

The dash board controls for the AC open and close it. Keep it

closed when washing, that is turn off all outside air, usually the

Off position.

Once this flap is closed (visually look to be sure it is completely

closed... and the seal is fully intact all the way around, as that

can let in outside air, and water), you can wash fairly secure

in the knowledge that water will not enter the interior ducting.

BTW, the flap is not at the bottom of the cavity, as that would

let in rain water that puddles before it drains out, in heavy rain.

The flap bottom is at least 1 inch up from the bottom of the

cavity.

I've recommended washing for over a decade now. It has solved

the smell issue 9 out of 10 times.

Ever get dead leaves on your passenger seat wheel well carpeting?

Ever wonder how they got there? Yes, in through the external

grill, past the flap, into the ducting, and past the fan, and then

stuck against the inside register grill, until the leaf ages, breaks

apart and lands on the carpeting.

Oh, do visually inspect the inside outlets for hot air under the

dash to your foot area for leaves being held there. They

can smell, too. Though they are dried out, and smell little

compared to leave debris stuck in the external cavity,

that gets morning dew condensation moisture that creates

mold growth.

> One of our cars, a volvo has wires inside there as well. I wonder

> if that would be a problem as well.

Ask at the volvo dealer what those wires are for. Are they

loose? Or in a pattern?

My first guess is to hold the bigger leaves from entering the

interior flap area,

to prevent them from touching the flap seal, and to direct the dead leaves

downward, towards the drain, to be dried out, break apart, and go down

the drain.

I'd like to know when you find out, so post to the list, please. Thanks.

Pete