Spend two minutes inside a Tesla with the air filters running and even the world’s most polluted air is reduced to a safe level. Run the car and filters a few more minutes, and pollution levels in the outside air start to fall. So says Tesla Motors — based on placing one of its Tesla Model X crossovers inside a badly polluted plastic bubble for 10 minutes.
Tesla’s point is that in the scheme of things around the world, air pollution is a bigger threat to health than car accidents. The world’s more polluted cities reduce life expectancy by 6-23 months, so time spent in Tesla with the cabin air filters full-on, in what Tesla calls Bioweapon Defense mode, might get back a bit of those lost hours and days. Tesla has the new air filters on its Model X crossover and new production of the Tesla Model S sedan.
To show the world how its filtering system works, Tesla created a sealable bubble 2-3 times as long, wide, and high as the Model X, which they placed inside. They pumped it full of hyper-dirty air, 1,000 micrograms per cubic meter (µg/m3) of PM2.5 matter versus the EPA’s upper limit for good air quality of 12 µg/m3. PM2.5 stands for particulate matter less than 2.5 microns in size; for comparison, dust and pollen are 10 microns and a human hair is 50-70 microns.
Lab techs wearing gas masks got in the car and activated the Bioweapon level of air filtration. Within 2 minutes, pollution inside was 1/100 of the original level (blue line in chart above) and then the big Tesla air filters started to scrub the air outside, reducing pollution by almost half.
According to the Tesla blog, “We developed a HEPA filtration system capable of stripping the outside air of pollen, bacteria, and pollution before they enter the cabin and systematically scrubbing the air inside the cabin to eliminate any trace of these particles. The end result is a filtration system hundreds of times more efficient than standard automotive filters, capable of providing the driver and her passengers with the best possible cabin air quality no matter what is happening in the environment around them.”
At the Model X launch last fall, CEO Elon Musk said, “This is a real button … a Bioweapon Defense Mode [button] …. We’re trying to be a leader in apocalyptic defense scenarios. [The protection is] on the levels of a hospital room,” apparently referring to how hospitals filter their air, rather than the number of patients laid low by infections contracted in the hospitals.
Tesla has three filtration modes: recirculate the air inside the car, draw in outside air with some (not-quite-HEPA) filtration, and invoking the Bioweapon Defense Mode and Tesla’s huge HEPA filters.
Not everyone is 100% on board with the Tesla bioweapon setting. As bioweapons experts told Gizmodo, 0.3 micron HEPA filters (and costlier 0.2 micron filters that take more energy to draw air across) will filter bacteria, pollen, dust, and spores. But it likely won’t be enough to hold back viruses that are even smaller.
From time to time, other automakers have claimed their vehicles scrub the outside air clean, or at least some of the air. Makers of hydrogen-fueled cars such as the BMW 7 Series hydrogen car — which burns hydrogen in a traditional engine — emits out the exhaust pipe cleaner than the air drawn in to the engine.
Citing the World Health Organization, Tesla says the average annual concentration of PM2.5 pollutants includes these cities:
The time Tesla owners spend in their cars in these high-pollution cities, as well as in well-filtered homes and offices for the affluent, would have a positive impact on their longevity.