Introduction To The Classification of Fume Hoods

Fume hoods, as indispensable safety equipment in laboratories, come in a wide variety of types with different functions. The following is a detailed classification introduction of fume hoods:

First, classification by exhaust method

Top exhaust type: This type of fume hood is suitable for thermal processes, and harmful gases are discharged through the top exhaust port.

Bottom exhaust type: This type of fume hood is suitable for cold processes. Harmful gases are discharged through the bottom exhaust port to ensure uniform air velocity in the working area.

Top and bottom simultaneous exhaust type: It is suitable for processes with unstable heat generation. The ratio of top and bottom exhaust volumes can be adjusted according to the changes in heat generation inside the cabinet to achieve a uniform air velocity.

Second, classification by air intake method

Fully exhaust fume hood: It is a widely used type that takes in air from the room, circulates it within the hood, and then exhausts it to the outside.

Supply air type fume hood: When the fume hood is installed in a room with heating or temperature and humidity control requirements, in order to save energy consumption for heating and air conditioning, the supply air is taken from outside, circulated inside the hood and then discharged outside.

Variable air volume fume hood: By adjusting the sensor of the valve, the air volume is changed to achieve the given face air velocity. It is suitable for occasions where high precision is required for exhaust air volume.

Third, classification by usage status

Integral lower open type: Compact structure, suitable for laboratories with low space requirements.

Floor-standing type: Good stability, suitable for scenarios where large experimental equipment is placed.

Two-sided and three-sided glass types: Offer a broader field of vision, facilitating the observation of the experimental process.

Desktop type: Compact in size, it is suitable for placement on a laboratory bench and is ideal for laboratory environments with limited space.

Integrated type: It can be customized according to the specific needs of the laboratory to achieve the integration of multiple functions.

Fourth, classify by the presence or absence of external pipelines

Exhaust type fume hood: Harmful gases are directly extracted to the outside through external pipes to ensure the cleanliness of the laboratory air.

Ductless fume hood: It is equipped with purification devices such as activated carbon filters to adsorb harmful gases inside the cabinet, eliminating the need for external pipes.

Fifth, classification by special functions

Heat-resistant and acid and alkali corrosion-resistant fume hood: For scenarios where electric furnaces need to be installed or corrosive experiments need to be conducted, its countertop, backing plate, side panels, and selected faucets and gas nozzles all have anti-corrosion functions.

Explosion-proof fume hood: Designed for handling flammable and explosive substances, it features fire prevention and explosion-proof properties.

Biosafety fume hood: Specifically designed for handling biohazardous substances, it features additional safety measures to prevent the spread of microbial aerosols.

Walkable fume hood: It allows laboratory personnel to work inside the fume hood and provides a larger operating space.

Sixth, classification by material

All-steel fume hood: The main structure and internal components are all made of stainless steel or carbon steel, which has good corrosion resistance and durability.

Steel-wood fume hood: The main structure is made of steel, and the internal components are made of wood, which can effectively reduce noise and vibration.

All-wood ventilation cabinet: The main structure and internal components are all made of wood, which has good sound insulation and heat preservation effects.

PP fume hood: Suitable for laboratories with high requirements for corrosive substances such as acids and alkalis.

FRP fume hood: It has excellent corrosion resistance and weather resistance, and is suitable for various harsh environments.

Seventh, classification by air flow organization mode

Full exhaust fume hood: The entire working area is in an exhaust state, and all gases are discharged from the laboratory.

Partial exhaust fume hood: Only certain areas or parts of the area are in the exhaust state, while the rest of the area is in a positive pressure state.

Fume hood without exhaust: There is no exhaust outlet inside the fume hood. The gas is purified through a filter before being discharged outdoors.

To sum up, fume hoods can be classified in various ways, and each type has its specific applicable scenarios and functional features. When choosing a fume hood, a comprehensive consideration should be made based on the specific needs and conditions of the laboratory.