Air Purifier for the Car

Diesel trucks: a love-hate relationship if there ever was. We play with plastic models as kids, and drive wanna be styled pickups as adults. Like the railroads before them, today’s transports cut a wide path, but not a clean path.

Serious landscape darkeners are soot from diesel fumes and dust from rubber tires.

Asthma Cause: Diesel Exhaust?

Latex Allergy Cause: Tire Dust?

Black rain, black snow: everything along an interstate corridor has this oily finish, with tiny soot particulates waiting to flurry into the air an auto moves through.

Brake dust, some of which still contains asbestos, accumulates as millions of brake shoes wear over billions of miles traveled. It builds up along the highway.

Mechanics working on brakes and clutches are trained to avoid generating clouds of fibers, but every vehicle on the road raises a huge cloud of roadside dust.

Brake Dust: Another Allergy Cause?

Cars and Purer Air

Clean air standards have made today's landscape look cleaner, and heavy traffic is easier to breathe in than it once was. But appearances deceive.

Airborne particles can be classified as coarse ( bigger than 2 micron), fine (0.1 to 1 micron), and ultrafine ( 0.02 micron).

Catalytic converters are now standard exhaust cleaning controls on every new gas powered automobile. Modern catalytic converters break down engine exhaust into fine particles called micron soot. Fine and ultrafine particles are a minor component by weight, but they are significant by number, which makes them dangerous to health. Small enough to evade our natural filters and be inhaled deep into the lungs, they can trigger an inflammatory response, causing serious health problems.

Particle pollution is connected with heart attacks, irregular heartbeat, lung disease, and asthma.

Heavy Metals

Heavy Metal in the air is not just loud music.

Like the trucks, the more numerous cars shed copper, lead, zinc, nickel, iron, antimony, and cadmium from wearing parts. A three-way catalytic converter purifies air in an car's exhaust system, using platinum, palladium, and rhodium as catalysts.

A ceramic biscuit is coated with these metals which speed up the high temperature air purification process. The ceramic catalyst is made from a lightweight, fragile material with a honeycomb structure.

Road debris striking the converter or vibration from broken exhaust pipe supports can cause a catalyst fracture. When a ceramic catalyst is fractured, the broken pieces can rattle around and grind into powder.

Rhodium, platinum, and palladium content of soils from U.S. roadsides is sometimes dense enough to consider recovery operations.

Mining pollution along the road?

Well, nobody has proposed that, but the point is made, highway roadsides accumulate toxins.

Lead, added to automotive fuels from 1926 to 1984, permeates the soil along any route that carried traffic during those years. This "legacy lead" may not line recently built interstates, but the older U.S. route running parallel may be loaded.

All pollutants along the highway accumulate and peak just before rains.

A good thunderstorm is an efficient purifier, air is purified and pollutants washed off the right-of-way.

One study found air purity in vehicle interiors was only 24% better than roadside measurements.

That's with windows up.

Heavy stop-and-go traffic means your vehicles' interior is more likely accumulating smog, exhaust, dust, and other impurities.

Smog is Ozone

Sunlight is required to produce smog, so ozone levels are highest in the summer. I rant at length about ozone (under indoor air quality on navbar). Since ozone is an even greater part of the air purity problem, I see little purpose for car air purifiers which add ozone while the vehicle is occupied.

Here is a good use for ozone emitting room air purifiers you were thinking of trashing: put the purifier in the auto and plug it in overnight. Ozone will build up substantially in the interior, oxidizing VOC’s. In the morning, remove the purifier from the car, and ventilate the interior completely before driving.

Carbon monoxide (CO) is a consequence of every combustion process, including cigarette smoking.

CO sticks to vital oxygen carrying hemoglobin in our blood, creating accident causing fatigue.

No car air purifier can filter carbon monoxide, which is concentrated along roads.

Carbon dioxide builds up inside an occupied cabin. While not directly toxic, it will cause discomfort.

VOC: Unsafe at any Speed

EPA has identified 21 toxic chemicals in highway air. Some toxic compounds are present in gasoline and are vaporized when gasoline evaporates or passes through the engine unburned.

Benzene, formaldehyde, acetaldehyde, 1,3-butadiene, polycyclic hydrocarbons, and fuel additives such as methyl tertiary butyl ether (MTBE) are present wherever there are autos.

Solvents used in cleaning and repair operations drip onto the pavement.

Leaking antifreeze from radiator hoses is extremely common, as are power steering fluid leaks.

Ions and Ionizers

Ions and their effects on health are discussed under the technology navbar, but the upshot is that rare negative air ions are "good" for particle cleaning and health.

Positive ions and a positive leaning air ion balance are considered "bad." As air rushes over the exterior metal skin, negative charges are stripped away. Positive ions build up in interior air, causing stimulation followed by fatigue. This is why the car air ionizer has become so popular.

Air In Cars

Flow through ventilation is required by law: when the A/C is set to recirculate, all cars still exchange some outside air to maintain adequate oxygen in the vehicle interior.

This admits exhaust fumes and allergens. Oil leaking on hot engine parts or dripping rubber fuel lines may produce a slight smell of gasoline inside the cab. Many drivers will not realize this smell is coming from their own ride.

One more phrase has been introduced: "Love that new car smell."

Chemicals Cause New Car Smell

Old automobile smells can be just as bad. When you appraise a used car ask yourself if the previous owners smoked, used chemical upholstery cleaners, repainted interior metal work, or used solvent containing plastic patching compounds.

Did the doors, window gaskets, or moon-roof ever leak? Wet carpeting and insulation can make mold very difficult to get rid of. Some models have incurably wet A/C systems, breeding mold and blowing it in riders faces. Old heater cores may have tiny anti-freeze leaks, making almost imperceptible smells in the air.

Dust levels in interiors can be far beyond what a small ionizer air purifier can handle. Ionic air purification is not really air cleaning, it flocks particles into groups too heavy to float in air. A car has powerful air currents which disturb settled dust. Frequent vacuuming and damp cloth cleaning should accompany installation of an air purifier.

Several manufacturers, mostly from Europe and Asia, have introduced built-in cabin air filters.

Some cleaning products can be toxic in a car's air. Interior air freshener sales continue at a brisk pace. A vehicle interior is more confined than residential rooms: smoking and side stream smoke are especially unhealthy inside an already toxic car. Rooms can be painted over, furniture and carpets removed.

Tars and particles from smoking can never be removed from automobile headliners and upholstery.

Air Purifiers for the Road

Driving a car can be our single most toxic activity. There are many models of auto air cleaners available. China has thousands of products, which fit the low budget mom and pop electronics explosion there. Most are small ionizers, and can be plugged into the car's 12v DC cigarette lighter socket. Few have any ability to actually purify air in cars, with its high impurity levels.

As with indoor air cleaners, better car purifiers have real fans and activated carbon for toxic chemicals.

Some can also double as a travel air purifier, using an optional AC power adapter.

Vehicle Air Purifiers: Reviews