When air quality exceeds the standard for dust or pollutants, in addition to wearing respiratory masks outdoors, government agencies may recommend staying indoors with doors and windows closed as much as possible. Living inside a building can partially protect residents from outside dust and pollutants and prevent the easy flow of outside air as most building constructions are closed. However, the characteristics of the indoor air can lead to increased humidity and the growth of bacteria, mould, and airborne diseases. Residents may often experience discomfort due to stagnant and non-circulating air which can result in Sick Building Syndrome such as headaches, skin or eye irritation, difficulty breathing, coughing, and sneezing. These illnesses are more likely to occur in those who spend more time inside a building than outside. Therefore, it is also crucial to pay attention to Indoor Air Quality (IAQ) as it greatly affects the health of those who reside inside a building.

Indoor Air Quality Testing is the process of measuring the quantity of particles and gases, temperature, and humidity in the air inside a building. In a residential building, the quality of the air is determined by the ability to maintain good health and well-being for the residents. In a manufacturing building, the quality of the air is determined by the ability to produce high-quality products efficiently and cost-effectively.