The difference between fume hood and laminar flow cabinet 1/2

1、 Functional purpose
FUME HOOD
Main function: It is mainly used to eliminate toxic, harmful, odorous gases, vapors or dust generated during the experimental process, protect the health of experimental personnel, prevent pollutants from spreading to the laboratory during the experiment, and provide environmental protection. It is an important safety equipment in laboratories, widely used in operations that may generate hazardous gases such as chemical and biological experiments. For example, during chemical experiments, if toxic gases such as hydrogen chloride and sulfur dioxide are produced, the fume hood can quickly exhaust these gases outdoors.
Application areas: Widely used in chemical laboratories, biosafety laboratories, physical and chemical laboratories, etc., suitable for experimental operations that may produce harmful gases, such as chemical reactions, sample pretreatment (such as digestion, extraction, etc. involving volatile substances such as strong acids and bases)
clean bench
Main function: It is a device that provides a locally dust-free and sterile high cleanliness working environment. By filtering and sterilizing, dust removal, and controlling air flow, it prevents external impurities, bacteria, etc. from entering the working area, thereby ensuring that experiments are conducted in a relatively sterile environment. It is mainly used for experiments and operations that require high environmental cleanliness, such as cell culture, microbial detection, precision electronic component manufacturing, etc. For example, in cell culture experiments, a super clean workbench can provide a sterile operating environment to avoid contamination of cell culture.
Application areas: Plays an important role in aseptic operations in biomedical research, pharmaceutical industry, electronics industry, food processing and other industries, such as aseptic filling of drugs, formulation of injections, assembly and testing of electronic products, which require ultra clean environments.
2、 Working principle
FUME HOOD
A fume hood usually has an outer shell with a working area inside. Negative pressure is generated by the built-in fan to draw air from the working area into the cabinet. The air passes through structures such as workbenches, orifice plates (sometimes), and deflectors to form an orderly airflow, and finally passes through filters (if it is a fume hood with filters) or is directly discharged outdoors. This airflow organization method can effectively capture and discharge pollutants generated during the experimental process, preventing them from escaping into the laboratory environment.
The exhaust system of the fume hood can adjust the air volume as needed to adapt to the amount of pollutants generated in different experiments. Some fume hoods are also equipped with valves that can adjust the exhaust volume according to experimental needs.
clean bench
A super clean workbench is a device that draws in external air through a fan, filters it through a high-efficiency filter (usually a HEPA filter), removes dust particles, bacteria, and other microorganisms from the air, and then blows the clean air towards the work area at a certain speed and direction, forming a continuous sterile and dust-free air curtain to achieve high cleanliness in the work area. At the same time, the air in the work area is constantly circulating to maintain a dynamic and clean state.
The ultra clean workbench has different airflow modes, such as vertical airflow mode and horizontal airflow mode. Vertical airflow mode refers to the air blowing down vertically from above, covering the workbench; The horizontal airflow mode is when air is blown horizontally from one side to the other, forming laminar flow.