To indoor ventilation indoor ventilation, the higher the rate of exchange with the outside world, Nanjing Yuhuatai indoor formaldehyde detection, reduce indoor formaldehyde pollution effect is often obvious, but strong sources of formaldehyde, its release rate is volatile gradients or air Formaldehyde function values. Ventilation so that the value is reduced, and the release rate increases. Therefore, to increase the indoor air with the outside loop, for low formaldehyde pollution intensity of the indoor formaldehyde detection, for strong pollution control should be used in other ways. The main sources of PM2.5 generated Nanjing Xuanwu indoor formaldehyde detection is the process of daily power generation, industrial production, vehicle exhaust emissions in emissions after combustion residues, most of them contain heavy metals and other toxic substances. Generally, particle size 2.5 to 10 microns coarse particles mainly from road dust and the like; 2.5 microns or less fine particles (PM2.5) are mainly from the burning of fossil fuels (such as motor vehicle exhaust, coal), volatile organics.