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Phew…hey your air conditioner sure stinks!
by I.M. Cool
Appeared January/February 2001 Cool Profit$ Magazine
© 2001 All Rights Reserved
I could be wrong but I don’t remember cars of the 70’s and 80’s blowing out smelly air-conditioned air. It was in the early 90’s when I first heard my niece complain that her new Plymouth minivan had developed a rude behavior whenever she turned on the air. Now it seems to be a fairly common complaint. So much so that several vendors have jumped in with a variety of products that allow the technician to alleviate the problem.

Which leads me to one of the mysteries about this condition: why do auto dealers seem to be getting the resulting service business, and not the independents? (If you don’t believe that, ask the vendors who most is buying their product.) Certainly an answer is that most of the vehicles that suffer from stinky air are still under warranty at the time, a dealer gimme. Still though, this is an ongoing problem. Could it be that independent service shops feel guilty about this service, like maybe they’re peddling snake oil? Hopefully we can rearrange some of those ideas.

“Houston, we HAVE a problem”
(I couldn’t resist)
Condensation forms on cool evaporator fins and tubes and collects in the pan. Inlet air brings along contaminants like dirt, pollen and plant and animal debris, some of which is deposited on the wet fins and in the pan. Additionally, if a system spends much time in re-circ mode, it also gathers matter like pet hair and nicotine and tars from cigarette smoke. Another cause could be leaking evaporators allowing oil to coat the fins. Certain evaporators, housings and pans are more prone to accumulating these contaminants than others.

Armed with the nourishment (contaminants) listed above, the warm, moist, dark, environs of the housing encourage beasties (microorganisms, mold, mildew, fungi, bacteria, etc.) to form and multiply. Being alive and growing means they produce gas. This gas, a volatile organic compound, IS the problem: its moldy odor stinks.

Car manufacturers turned to professionals, so did I
The auto manufacturers turned to vendors to solve their odor problems. I asked these companies several questions to assist in preparing this article. Several of them graciously responded.

AirSept, Inc. provided a more scientific description to what I called beasties. They report that independent laboratories have identified Aspergillus, Cladesporium, Penicillium along with others as the fungi growing on coils and other parts of the system.

Problem vehicles
I asked the vendors which vehicles seem to be most affected. Four Seasons reported that while all vehicles are affected to some extent, their Tech Line receives the greatest number of complaints for the front wheel drive Daimler-Chrysler/Dodge family of mini-vans. The evaporator odor problem could be found in Mitchell-On-Demand Technical Service Bulletins for 1993 model year vehicles covering Ford (Bulletin # 98-2-7), General Motors (99-01-39-004, & 53-12-12A), and Daimler-Chrysler/Dodge (24-11-97).

airco_applied.jpg (32985 bytes)
(Click thumbnails for larger image). Below: Innotec demonstrates how to apply their aerosol product. If easy access to the evaporator is unavailable, drill a 7/32” hole in the air intake of the evaporator assembly. Be sure to plug the hole when you’ve finished.

AirSept believes that “limited under hood space in downsized vehicles, along with increased need for air cooling in vehicles with higher glass content, led vehicle manufacturers to reduce the size of a/c evaporators while simultaneously increasing the fin count. These more densely packed evaporators trap and hold more moisture.”
Cliplight Manufacturing Company has no evidence that R-134a evaporators are any worse to foul than those using R-12. They point out that in fact, an R-12 vehicle will be at least eight years older and therefore likely to be packed with eight more years worth of contaminants.

The cure(s)
While many products include a deodorizer as part of their package, for obvious reasons we did not invite pure deodorizer vendors to this party. Legitimate cures for evap-stink are: 1. Apply a microbial and moisture-resistant coating to the coil to reduce the problem in the first place, 2. Clean the evaporator (and pan, housing, air inlet, etc.) and 3. Using an electronic timer to cycle the blower at certain intervals after the vehicle has been shut down. The latter action dehydrates the evaporator in less-than-humid areas, which stifles microbial formation.

Many manufacturers now install evaporators that have been coated with both antimicrobial and hydrophilic (i.e. water shedding—thanks again AirSept) materials. However, those coatings are not permanent. Once depleted, the evaporator can then become a microbial breeding ground.

AirSept Inc.’s Air Cooling Coil Coating is an aftermarket product designed to replace a coil’s lost coating, or apply one to coils without such coating. It combines an antimicrobial and an acrylic coating to the coil that is said to last three seasons in normal A/C use. There is a Pre-Wash product that should be used in case the system, plenum chamber or air ducts are cluttered with leaves and other debris.

Of course, anyone can perform a truly thorough job by R&Ring the evaporator, and maybe the heater, and manually cleaning them with a solvent. But how many customers are willing to pay for that service, especially if the system is otherwise working fine? An alternative is to spray the evaporator face and/or housing with an aerosol cleaner and let the liquid carry the contaminants down the pan’s drain.

airsept_coating.jpg (25998 bytes)
AirSept’s Coating shows its stuff. Water was sprayed on both aluminum samples. After one minute, beads still collect on the left, uncoated sample. No drops gathered on the coated piece.

To accomplish the above, all vendors agree that the coil must be thoroughly coated with their product to assure a good cleaning. Without disassembling the housing, there two methods to get product to the coil: 1. Removing a major component like the blower, its module or the motor’s speed control resistor, or 2. Drilling a small (7/16”) hole in the case. None of the responding vendors expressed it, but in Japanese vehicles a certain foam product can actually be applied directly into the blower housing. As it expands it fills over into the coil housing and soaks the coil. These cleanings are said to provide protection from six months to one year from application.

The labor time to complete this project runs between twenty minutes and an hour plus, depending on accessibility to the coil. With AirSept’s Coating, there is a curing time of twenty minutes after application. The vehicle’s heater must be on high, but there is no other technician involvement. The customer’s cost mentioned by the vendors ranged from $60-100 to perform the service.

After the service, if an electronic afterblow module is not installed, be sure to advise the car owner that operating the A/C system in Normal Mode (fresh air) as much as possible will help to reduce molds, and odors, from reforming.

Offer the service!
Besides the stink, the threat of sickness and disease carried by airborne contaminants is a major concern worldwide. I found no claims that auto air systems were the cause of any specific illness. However, certain molds are known to produce mycotoxins, which can produce short-term and long-term adverse health effects in humans. These include headaches, dermatitis, recurring colds and flu-like symptoms, asthma, sinus infection, burning sore throat and more. Experts admit that mycotoxin exposures are difficult to diagnose because other diseases can cause the symptoms.

evap_spray1.jpg (31077 bytes)
Below: Dust and other debris that builds on evaporator face provides food for micro bacteria to grow. Foaming the entire face allows the contaminants to flow out the A/C drain. Photo: Mobile Air 2000.

Also, and this is important, even dead fungi can produce these toxins. Allergies are common when air currents carry away the spores (similar to plant seeds). It’s the spores that do the damage when inhaled. So, don’t be afraid to offer an evaporator cleaning service to your customers. Besides getting rid of the odor problem, you may also be helping to keep the vehicles occupants healthier at the same time. Remember, where there is odor there is definitely mold. Where there is mold there is danger to people, especially young children suffering from asthma. Treat this condition with the seriousness that it deserves. Offer this service proudly.              $$$

Editor: Thanks to the following contributors to this article:
• AirSept, Inc., 1155 Allgood Rd., Ste 6, Marietta, GA 30062-2243; 770-321-4826, 800-999-1051, Fax: 770-973-4826; Email: info@airsept.com ; Web: www.airsept.com; Product: Air Cooling Coil Coating, 2. Electronic Evaporator Dryer

• Cliplight Manufacturing Co., 961 Alness St, Toronto, ON Canada M3J 2J1, Ph: 416-736-9036, 800-526-7096, Fax: 416-736-9138; Email: sullivan@cliplight.com; Web: www.cliplight.com; Product: EvapClean

• Four Seasons Division of Standard Motor Products; 1801 Waters Ridge Dr, Lewisville, TX 75057; 800-433-7508; Email: Robyn.Hartwell@4S.com ; Web: www.4s.com; Product: #59052 AIRCO

• Innotec NA, 1745 Bonhill Rd Unit #3, Mississauga, ON CANADA, L5T 1C1, Ph: 905-565-1225, 800 981-9688, Fax: 905-565-1277, 800-543-6533, Web: WWW.INNOTECNA.COM; Product: Airco Clean Control

• Mobilair 2000, 5 Colomba Dr, Suite 167, Niagara Falls, NY 14305-1275; Ph: 905-542-8279, 800-538-6057, Fax: 905-812-1172, Email: info@keep-it-kool.com ; Web: www.keep-it-kool.com; Product: AIR REPAIR™

Soon you will be able to check in with “current” radiator and a/c industry vendors on the web at: www.imcool.com/buyersguide/.
Vendors: If you would like to be listed as a vendor to the automotive (and Heavy Duty) radiator and A/C service industry, please call, fax, email or fill out the form on the imcool.com web site. Look for Buyer’s Guide Data Entry Form.
Your cost to be listed on the web site and in the 2002 Annual Guide is only $12. For that, you also get a subscription to Cool Profit$ Magazine. In addition, your web listing will be maintained for free (name, contact, address, phone, email, URL, etc.). One heck of a deal.

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