Wanxiang exhaust hood is a type of local exhaust, which is immediately discharged nearby after harmful substances are generated. This method can remove a large amount of harmful substances with less air volume, save energy and have good effects. It is a feasible and economical way to improve existing laboratory conditions and adapt to the ventilation construction of new laboratories.

When arranging the universal exhaust hood, the following points should be noted:

1.For different emission situations of harmful substances, different exhaust hoods are used. For example, for spectrographs, enclosed exhaust hoods are generally used; For the exhaust of the experimental table or slot, a side suction hood can be used; For heating tanks, it is advisable to use umbrella shaped covers.

2.Full room ventilation: Natural ventilation and mechanical ventilation are required. Commonly used in rooms without ventilation hoods and where harmful substances need to be discharged.

Natural ventilation refers to the use of the temperature difference between indoors and outdoors, that is, the density difference between indoor and outdoor air, to generate hot pressure and discharge harmful gases from indoors to outdoors. When air flows freely through windows, it is called unorganized natural ventilation; When relying on certain air inlet and outlet shafts to allow air to flow in the required direction, it is called organized natural ventilation.

Mechanical ventilation refers to the use of mechanical ventilation when natural ventilation cannot meet indoor ventilation requirements, especially for hazardous materials warehouses, drug warehouses, etc. Although natural ventilation is available, mechanical ventilation must also be used to consider accident ventilation.

3.Try to get as close as possible to the source of harmful substances.

4.The exhaust hood should be convenient for experimental operation and equipment maintenance and repair.