The controlled experiments are conducted in a 18.26 m3 stainless steel environmental test chamber maintained at 23 °C±0.4°C and 50%±5% relative humidity with an air exchange rate of 0.5859 per hour. Air samples can be drawn from the chamber via a suction pump into a canister to determine VOCs. The Dust-Trak portable samplers and IAQ-Trak monitor are put in the centre of the chamber to monitor particulate matters, temperature and relative humidity, respectively. A Telfon tubing connecting with CO analyzer, SO2 analyzer, NO-NO2-NOx amalyzer and THC monitor is put in the chamber