Fume Hood

It is divided into three categories: upper exhaust type, lower exhaust type and upper and lower exhaust type. In order to ensure uniform wind speed in the working area, the fume hoods for the cold process should adopt the lower exhaust type, and the fume hoods for the hot process should adopt the upper exhaust type. For the process with unstable heat generation, exhaust ports can be set up at the top and bottom to adjust the ratio of the upper and lower exhaust volume with the change of heat generation in the cabinet, so as to obtain uniform wind speed.

Full exhaust type fume hood : The indoor air intake is circulated in the cabinet and then discharged to the outside, which is called full exhaust type. This is a very widely used type.

Supplementary air fume hood : When the fume hood is set in a room with heating or temperature and humidity control requirements, in order to save heating and air conditioning energy consumption, the method of taking supplementary air from the outside and circulating it in the cabinet and then discharging it to the outside is called supplementary air fume hood.

Variable air volume fume hood : The ordinary fixed air volume system requires manual adjustment of the fixed blade air valve to adjust the exhaust volume of the fume hood. When the valve is adjusted to a certain angle, the desired surface wind speed is achieved. Variable air volume control is to change the air volume to achieve a given surface velocity by adjusting the sensor of the valve. Of course, the standard type has low cost and the variable air volume has high cost, which is suitable for occasions requiring high precision.

Fume hoods are classified according to the use status:

They can be divided into integral lower open type, floor-standing type, two-sided type, three-sided glass type, desktop type, one-piece type, and special fume hoods designed for radioactive experiments, synthetic experiments, and perchloric acid experiments according to the needs of different experiments.