Market Feature: Cabin Air Filter

As the air quality has gradually degraded in many urban and rural areas–with the advent of factory farming techniques, for example–harmful pollutants like ground level ozone and suspended particles like pollen have become an issue that car makers have been forced to address. The cabin air filter is their response. It’s like a HEPA filter for your car: it cleans the air you have to breathe.

To find out more, I headed for Charlotte, North Carolina. I had never been to the home of NASCAR and, as the story goes, I still haven’t.

That’s because the manufacturing facilities of Wix, the filter manufacturing division of multi-billion-dollar Dana Corporation, are in Gastonia, an old cotton and textiles center nearly an hour from the famed Lowes Motor Speedway, but I’m getting off track.

There are two basic types of cabin air filters. Single media filters simply catch dirt and particles, and stop them from blowing through the vents inside the car. Combination filters add activated charcoal that also absorbs odors.Delta Sonderman is the operations manager of Wix Helsa–a joint venture with European company Helsa and Dana’s oldest cabin air filter (CAF) manufacturing facility. Sonderman explains that the pulverized charcoal in combination filters has to be tuned to detect and absorb certain odors. This task, she says, fell to the Society of Automotive Engineers which decided in its wisdom on two bad smells: “n-butane (that’s from sewage or farms),” she explains, “and diesel smell.”

(I privately suggested to myself that they might consider a third: Southern Barbecue, the smell of which still lingered from lunch.)

“We’re probably behind the Europeans,” offers Bruce Johnston, the company’s CAF brand marketing manager. He muses that this was likely the result of their being ahead of the North American curve as it concerns the passenger environment. Colleague Bruce Coffey, engineering manager and chairperson of the Society of Automotive Engineers’ Air Cleaner Test Methods Commit-tee, says this isn’t hard to understand if you’ve ever spent much time on European roads, following diesel-powered vehicles all day.

In any case, CAFs started appearing on cars here in 1995, and are destined to be on 80% of new vehicles sold by 2005. Today they are on about one in five.

They differ from the rest of the filters that people are used to thinking about, oil and air filters, because they do not protect the mechanical innards of the car.

Too often, says Johnston, this means they are not replaced when they should be, at less than 20,000 km. And a dirty filter is worse than no filter at all, because it impedes airflow, blocking air conditioning and heating. Few car owners know whether their car has one, and even many car dealership and independent garage personnel are unaware.

“And if they don’t know,” said Johnston, “it’s no wonder the consumer doesn’t know.” It doesn’t help matters much that there isn’t even a remotely standard location. The people at Wix have to work hard to get this information from companies they don’t supply at the original equipment level. Some filters are under the dash; some are under a plastic panel in the engine bay. Some are easy for a consumer to change. Others, says Johnston, “nearly require you to take part of the engine out.”

On the two used Ford vehicles brought in from a local used car dealer, one had a panel marked “Passenger Compartment Filter,” the other had an icon that looked like a man sitting in front of a beaded curtain, threatened by a large arrow. This supposed universal icon was universal only in its enigmatic nature. Plain language or not, the filters on both cars were filthy, clogged with dirt, leaves, and bugs.

That shouldn’t have been a surprise. According to studies, the pollution in the passenger compartment can be as much as six times as concentrated as the outside air. Everything from the cars ahead gets drawn into the vehicle. Cabin air filters can reduce the amount of particulate matter flowing in–though no one was able to say by how much–and combination filters, with their layer of activated charcoal, can remove at least two of the most offensive odors people are likely to encounter.

They can only do this if they’re changed regularly, of course, and whether consumers will remember to do this is still up in the air.

Jim Betournay is national sales manager branded products, ArvinMeritor Light Vehicle Aftermarket, which manufactures the Purolator brand.

“It’s so new and a lot of people don’t even know that they’re in their vehicles yet. It’s even new to me,” he says. Betournay adds that the coverage isn’t too onerous from an investment standpoint, the Purolator program with decent coverage being only 16 part numbers. The barrier is really about awareness.

“It’s only in the past few years that people have started to focus on it.” Half the problem is awareness, he says; the other half is knowing where the cabin air filter is located. To help on this front, ArvinMeritor has included a locator guide with installation instructions on its Purolator website, www.pureoil.com.

“It’s a growing market and we haven’t even begun to see what this sector of the market can do for us. It comes down to the fact that technicians just aren’t aware of it. We need to work a lot harder getting the word out. Everybody in the business knows it’s out there.” What they aren’t sure of is how to get the market kick-started.

“I think everybody in our industry is talking the same story about cabin air filters, but we still need to get the consumer aware of this category.”

How do customers know?

Consumers may not be aware of the fact that they have a cabin air filter in their car, but they may be aware of when it’s past its useful life without even knowing it.

Clues such as reduced air flow through the vents, or an increase in odors are the biggest indicators, though the best way to tell is still a visual inspection.

“If it’s covered in dirt and grime and bugs and leaves, you know it’s time to change it,” says Mark Robertson, product manager, G.K. Industries. “On some of the higher end vehicles with the activated charcoal, it gives you a little better hint, because [when it’s worn out] you get the smell.”

Robertson says that the filters can handle quite a bit of dirt before a consumer might be able to tell that his vents aren’t working as well as they should, but that other items, especially leaves, are prime candidates for blocking air flow.

So a consumer complaining about a low fan pressure may in fact be complaining about a clogged cabin air filter without knowing it.