Air Quality inside your car

Ahh, I remember my days of commuting to work in northern Virginia…with NPR and a cup of coffee for 45-50 minutes, the little cabin of my Ford Ranger hugged around me like a safety blanket against the traffic and elements.  For many commuters, their car is a sanctuary of control, from temperature to volume to speed.  What we don’t control, and don’t even know about, is the air pollution that infiltrates our little safety zone.  Without knowledge, we can be helpless against it. 

For those living in or traveling through high-traffic areas, air pollution can be significant.  According to research at University of California Riverside, your car is like a small box with holes in it.  What’s inside the box, eventually becomes the same as what’s outside the box.  The time this takes depends on fan speed, ventilation mode, and cabin air recirculation.  

According to UC Riverside, when encountering heavy pollution, it is best to close the windows, set the ventilation to “recirc” and set the fan on low.  This will allow the car’s cabin filter to take out some of the ultrafine smog particles.  However, this setting should only be used for a short time, because the concentration of carbon dioxide from passengers’ breathing starts to become high.  Surprisingly, increasing the fan speed will increase ventilation, even without changing from the “recirc” setting, because the car cabin is not tightly sealed.  

Research from Washington University in the St. Louis School of Engineering and Applied Science would add one more step: turn on your air conditioning.  Technically, the fan and recirc settings are the same whether you’re running the AC or not.  However, when the air hits the cool surface of the evaporator, the pollutant molecules are attracted to it and tend to stay there instead of continue into the cabin of your car.  Students’ research showed that the pollution level was reduced between 20 and 34 percent by turning the AC.  

Back at UC Riverside,  Professor Heejung Jung says the best ventilation setting would be a “fractional recirculation”, where the flap controlling recirculation is opened at specific angles to improve ventilation.  His team of researchers are assembling a database of specific car models and test data, to help the average car owner achieve better air quality using the controls they do have. 

Then, there are the pollutants you can control.  Dust and mold are two allergens that you can clean out of your car, to a large extent.  

  • Keeping food wrappers and crumbs cleaned up and mopping up spills quickly will prevent mold and mildew from growing.  
  • A regular quick vacuum and wipedown with a damp cloth (no cleaning chemicals needed) will reduce dust in the air.  
  • Changing the cabin air filter regularly (at least every 15,000 miles) enables the car to filter the air too.  Definitely change the filter if you smell a musty smell when turning on the air conditioning, as that could be a sign of mold growing on it. 
  • If you notice a foul smell when turning on the air conditioning, it may be that rodents have urinated on the cabin air filter or built a nest there.  Besides cleaning or changing the air filter, you can keep them out by using a safe rodent deterrent under the hood when you are not using the vehicle, and/or inside the vehicle when you are. 

Your car can benefit from a deep clean sometimes too (with the right non-toxic cleaners).  You don’t need a professional upholstery cleaner; even spritzing upholstery and carpets with hot water and soap and vacuuming with a wet/dry vacuum will remove deeper contaminants.  Make sure to do this on a warm day when you can leave the windows down for several hours to further dry and ventilate the inside so that mold growth doesn’t accelerate.

Some car companies have recognized the need for better air quality in the car and are building active monitoring and purification into their new models.  Volvo is one such company, which partners with CabinAir, a spinoff of Swedish air purifier company Blueair.  CabinAir electrically charges fresh air particles, then passes them through an optimized filter, in order to trap even ultrafine particles (pm2.5).  The system only allows 4% of harmful pollutants into the cabin (also filtering out 99.97% of airborne viruses and bacteria), compared with 50% using traditional cabin air filters.  This system can also be retrofitted into existing cars by installing the new CabinAir filter with charging system, and the NordZone Air Quality Monitor (which may be also synced with the NordZone App on your phone to provide the total view of interior and exterior conditions).  The NordZone Air Quality Monitor displays lights indicating when you have fresh air but not clean (too many pollutants), clean air but not fresh (too much CO2) or clean and fresh air, by sampling and measuring PM, VOCs and CO2.  Hyundai and Tesla are two other carmakers that have introduced air quality monitoring and cleaning in their new models. 

Bad outdoor air quality, just like slow traffic conditions, can be predicted and avoided.  The newest generation of cars will be equipped with proactive air quality guidance in order to allow the driver to take an alternative route before they even start driving, or guide them out of areas of worsening air quality.  Companies like BreezoMeter have constructed millions of “Virtual Sensors” which extrapolate air pollution based on data from real sensors and algorithms.  What a breath of fresh air for the commuter!