The main task of the smoke exhaust duct is to discharge harmful gases and smoke from the outside of the building when the fire occurs, ensure the safe evacuation of personnel and fight the fire, and is one of the important facilities in the smoke control and exhaust system.

According to the "Technical Standards for Building Smoke Control and Exhaust System", the setting and fire resistance limit of smoke exhaust pipes should meet the relevant requirements, and when there is combustible material in the ceiling, the smoke exhaust pipes in the ceiling should be insulated with non-combustible materials. Therefore, the fire exhaust duct needs to have a certain high temperature resistance, and not all the air ducts need to have the heat insulation performance.

Although the relevant regulations do not stipulate that all fire exhaust ducts need to have thermal insulation performance, it is necessary in practical applications. The heat insulation of fire exhaust duct can reduce the influence of high temperature smoke on the pipeline, the surrounding environment and equipment.

At present, many people use galvanized steel air ducts as fire exhaust air ducts, but this kind of metal air ducts cannot meet the corresponding fire resistance limit requirements. Therefore, traditional and cost-effective fireproof wrapping practices will be used to enhance the fire resistance of metal air ducts.

The fire-proof wrapping method of smoke exhaust duct is relatively simple, which uses A-class non-combustible materials with excellent fire resistance (such as rock wool, glass wool, etc.) to cover the surface of the duct, and then fix and seal the material. The fire-proof wrapping material for smoke exhaust duct not only has excellent fire-proof performance, but also has thermal insulation performance. Therefore, after the use of this method, the fire smoke exhaust duct not only has the fire protection effect, but also has the heat insulation effect.

In addition to the fireproof package scheme, you can also use fireproof paint, the use of finished fire-resistant ducts, etc., but these methods can improve the fire resistance of metal ducts, but not necessarily have thermal insulation effect.

To sum up, not all fire exhaust ducts have thermal insulation effect, and it is necessary to heat insulate the ducts when there are combustibles in the ceiling. However, in practical applications, the heat insulation performance of the air duct is particularly important. Therefore, the heat insulation of the fire exhaust duct should be comprehensively considered according to the specific situation to ensure the normal operation of the smoke exhaust system and the safety of the surrounding environment.