1. The centralized type is to form a system of fume hoods on one floor or several floors, or the entire laboratory building is divided into one or two systems. It is characterized by fewer ventilators, less investment in equipment, and a certain adaptability to a slight increase or decrease in the number of fume hoods, as well as changes in location. However, due to the large system, the air volume is not easy to balance. Although each fume hood is equipped with a regulating valve, it is inconvenient to use, and it is not easy to achieve the predetermined effect. If the system duct is damaged and needs to be repaired, then the fume hood of the entire system cannot be used. Therefore, the laboratories that used a centralized system have been changed to a decentralized system one after another.
2. Decentralized is a fume hood or several fume hoods in the same room to form an exhaust system. Its characteristics are: the ventilator can be turned on and off according to the work needs of the fume hood, without mutual interference, easy to achieve the predetermined effect, and save energy than the centralized system, because the centralized system, as long as one fume hood is in use, it must be Turn on the big ventilator. Due to the small system, small exhaust air volume and small resistance of the decentralized type, the air volume and air pressure of the ventilator are not large, and the noise and vibration are correspondingly small.
