雾霾天开车外出,车里的霾多不多呢?过去我们认为,雾霾天,车里的空调一定要开成内循环,别让外面的霾进来。这样的认识对不对呢?下面的实验有可能挑战您一贯以来根深蒂固的常识。记者先测试室外PM2.5的浓度,大概在300微克每立方米左右,属于重度雾霾。然后,发动了汽车,测试汽车尾气部位的PM2.5浓度,数值停在了9200万微克每立方米。紧接着,再对车内的PM2.5进行测试,浓度大概在230微克每立方米左右。可见,车内PM2.5的浓度,并不比车外低很多。 Haze driving out, the car haze more? In the past we think, hazy days, the car’s air-conditioning must be opened into the inner loop, do not let the haze come in. Is not that correct? The following experiments may challenge your long held common sense. Reporters first test the concentration of outdoor PM2.5, about 300 micrograms per cubic meter or so, are heavy smog. Then, a car was started to test PM2.5 concentrations in the exhaust of the car, stopping at 92 million micrograms per cubic meter. Then, PM2.5 inside the car and then tested at a concentration of about 230 micrograms per cubic meter. Visible, the concentration of PM2.5 inside the car, not much lower than the car outside.