Laboratory fume hoods are classified according to the ventilation mode:

It is divided into upper exhaust type, lower exhaust type and upper and lower exhaust type. In order to ensure uniform wind speed in the working area, the lower exhaust type shall be used for the fume hood in the cold process, and the upper exhaust type shall be used for the fume hood in the hot process. For the process with unstable heat generation, the upper and lower exhaust outlets can be set up to adjust the ratio of upper and lower exhaust air volumes with the change of heat generation in the cabinet, so as to obtain uniform wind speed. PP pipe fittings

Classification according to air inlet mode:

Full exhaust fume hood: It is called full exhaust fume hood after indoor air inlet circulates in the cabinet and then exhausts outside, which is widely used.

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

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

Classification according to use status:

It can be divided into integral lower open type, floor type, two side type, three side glass type, table type, integrated type, and fume hoods designed for radioactive experiment, synthetic experiment, and perchloric acid experiment according to different experimental use needs.