Everyone spends about 80~90% of the time in the indoor environment (including in homes, offices or other buildings) every day in Taiwan. Good or bad indoor air quality affects directly the quality and efficiency of work. Therefore, it should be emphasized that the impact of indoor air pollutants on human health. We must improve effectively indoor air quality in order to protect our health.

In recent years, the issue of indoor air health hazards has gradually attracted attention, especially the changes in popular lifestyles in the past two to thirty years, although it allows people to enjoy comfort and convenience through air-conditioning systems in confined living spaces or office spaces , But following has also produced the problem of "Sick Building Syndrome". If the indoor ventilation is insufficient, pollutants will easily accumulate and cause deterioration of indoor air quality in closed buildings. The World Health Organization defines "Sick Building Syndrome" as: "Any abnormal human body symptoms caused by air pollution in buildings, such as neurotoxic symptoms (including irritation of the eyes, nose, throat, etc.), odor, asthma attacks, etc ." In 1982.

In addition, factors that affect indoor air quality may also come from outdoor pollutants, including exhaust gas from outdoor automobiles and factories, or microorganisms that breed due to the external air intake or filter of the central air-conditioning system that is not cleaned regularly. Molds and bacteria are especially prone to breed in Taiwan, because it is located in the subtropical zone and has a long-term humid and high temperature climate. Therefore, buildings must pay more attention to the regular maintenance of air conditioning and ventilation systems.