In winter, outdoor temperatures are low, and people tend to keep doors and windows tightly closed to maintain indoor warmth, resulting in poor air circulation between indoors and outdoors. Occupants continuously exhale CO₂ without corresponding ventilation measures, causing indoor CO₂ concentrations to accumulate continuously and greatly exceed standard levels. Photo credit: unsplash Research indicates that in ordinary living rooms with doors and windows closed, the activity of just two or...

In modern cities, people spend more than 80% of their time indoors. However, have you ever felt dizziness, throat discomfort, fatigue, or even difficulty concentrating in certain buildings? This may be due to Sick Building Syndrome (SBS), and one of the culprits behind it is Total Volatile Organic Compounds (TVOC). Photo credit: unsplash Sources of TVOC Total Volatile Organic Compounds (TVOC) is the sum of various volatile organic compounds indoors, which readily volatilize at room...

CO₂ is a colorless, odorless, and asphyxiating gas. Its indoor sources are primarily the combustion of carbonaceous fuels and human activities. When related activities such as cooking, heating, and lighting occur, CO₂ concentrations can reach elevated levels within a short period. An adult exhales approximately 22.6 liters of CO₂ per hour. In enclosed indoor environments without combustion devices, such as office buildings, hotels, shopping malls, gyms, and cinemas, human respiration is the...