1. The differences are as follows:

1. Different purposes: The purpose of sending and exhausting air at ordinary times is to eliminate residual heat, humidity and harmful substances; The purpose of fire ventilation is to prevent smoke and exhaust smoke. Smoke prevention means to maintain a certain positive pressure in the area to ensure that the requirements cannot be invaded. Smoke exhaust means to exhaust smoke in time to ensure the normal evacuation of personnel.

2. Different design wind speeds: Usually, the air supply and exhaust are always on. Considering the noise and operation cost, the control wind speed is generally not more than 11 m/s. The fire-fighting air supply and exhaust is the fire-fighting start, and the wind speed of the metal air duct is generally controlled not to be greater than 21m/s, and that of the civil air duct is not greater than 15m/s;

3. The calculation method of air volume is different: usually, the air supply and exhaust are calculated according to the air exchange times, and the air exchange times in different rooms are different, and some are calculated according to the dilution equation. Smoke control and extraction are generally calculated by unit area, and the amount of smoke extraction per unit area is the same (basement garage is also calculated by air exchange times);

4. The setting temperature of the fire damper is different: the temperature of the fire damper for exhaust air is set at 71℃. Fire air supply is 71℃, and smoke exhaust is 281℃.

second, contact:

it can be used * * *, and the fan does not have to be used independently, but it can be used at high and low speeds.

smoke exhaust system: a system that uses mechanical smoke exhaust or natural smoke exhaust to exhaust the smoke outside the building.

mechanical smoke exhaust: smoke exhaust fans are used to exhaust the smoke outside the building.

natural smoke exhaust: a smoke exhaust method that uses the buoyancy of hot smoke generated during fire and the action of external wind to exhaust smoke to the outside through the external opening of the building.

smoke exhaust fire valve: it is installed on the pipeline of mechanical smoke exhaust system, normally closed and meets the requirements of air leakage. It is manually and electrically opened when there is a fire or smoke needs to be exhausted, which plays the role of smoke exhaust. When the smoke temperature in the smoke exhaust pipeline reaches 281℃, it is closed, which can meet the requirements of smoke leakage and fire integrity within a certain period of time, and plays the role of smoke isolation and fire prevention.