The primary function of a chimney is to exhaust smoke and gases, improving combustion conditions. High-rise buildings typically feature varying numbers of vertical shafts, such as stairwells, ventilation ducts, air supply ducts, exhaust ducts, elevator shafts, and pipe shafts. When indoor temperatures exceed outdoor temperatures, the less dense warm air rises through these vertical channels. It escapes through gaps in doors and windows and various openings from the upper levels. Cold outdoor air, being denser, enters from the lower levels to compensate, creating the chimney effect. The chimney effect is the result of the combined action of thermal pressure due to the indoor-outdoor temperature difference and wind pressure from outside, with the former usually being predominant. The thermal pressure is directly proportional to the air density difference caused by the indoor-outdoor temperature difference and the height difference between the intake and exhaust openings. This indicates that the higher the indoor temperature is above the outdoor temperature and the taller the building, the more pronounced the chimney effect becomes. It also suggests that the chimney effect in residential buildings generally occurs only during winter. Theoretically, the midpoint of a building's height is considered the neutral zone, where rooms below this level are assumed to intake air from outside, and rooms above to exhaust air indoors.
Key points to note during the construction of chimney anti-corrosion:
1. Construction sites must be clean and well-ventilated, with harmful gas levels not exceeding the specified requirements. Flammable materials, except for those used in the anti-corrosion paint for chimneys, are strictly prohibited from being stored on the construction site. That is, pay attention to environmental safety and keep the site clean.
2. Smoking is prohibited on-site. Welding or open flame activities are not allowed within 10 meters. Explosion-proof lighting equipment must be used during construction. Workers should wear necessary protective gear, perform tasks in rotation within containers, and ensure adequate ventilation. Anti-slip measures must be in place, and workers must wear safety belts.
3. Once chimney anti-corrosion work is completed, when cleaning tools and containers with waste solvents, do not pour them carelessly and handle them properly. In case of any accidents, place them in designated areas.
