CABIN AIR QUALITY FACES SCRUTINY
Concerns that car cabins could trap in significantly higher levels of particulates and CO2 than outside air have led Emissions Analytics (EA) to develop a series of tests. It is evaluating both a car’s ability to filter external pollen and how car heating and air-conditioning systems trap in and circulate CO2.
“By the time the pollution actually gets to the pavement, it’s diluted quite a bit, so measurements in the middle of the road are much higher than at roadside monitoring stations,” explained CEO Nick Molden.
The second measurement covers heating, ventilation and air-con systems, which create a trade-off between exposure to pollution from outside and build-up of CO2.
Climate.gov puts the global average ambient CO2 level at 407 parts per million (ppm), but Molden said: “We’ve recorded up to 3000ppm within 30 minutes with just the driver in there, and it can go a lot higher. When you get past 1000, you start getting things like dry eyes, dry throat. When you get up to 2500, you start to get cognitive impairment – of the gentlest sort.
“It doesn’t become really, seriously unsafe, where you start losing consciousness, until you’re up to about 10,000ppm. But if it increases your reaction time from 0.5sec to 0.8sec, that has a safety implication.”
EA has assessed around 130 vehicles and found the worst performers to be Volvo for CO2 and Lexus for particulates. Jaguar, and specifically the I-pace, was best all-round.
The testing firm has begun work on an interior air quality rating process to inform buyers and policymakers.