1. Classification by material: The material of fume hoods can be divided into all-steel fume hoods, PP fume hoods, stainless steel fume hoods, steel wood fume hoods, glass fiber reinforced plastic fume hoods, etc.
2. Classification by function: The functions of fume hoods can be divided into standard fume hoods, desktop fume hoods, walk-in fume hoods (floor fume hoods), downdraft fume hoods (downdraft fume hoods) and conjoined fume hoods.
3. Classification according to exhaust modes: The exhaust modes of fume hoods can be divided into three types: upper exhaust mode, lower exhaust mode and upper and lower simultaneous exhaust mode.
4. Classification by appearance: The appearance of fume hoods can be divided into open fume hoods, push-pull fume hoods and integral fume hoods. Open fume hood usually connects the console with the laboratory, push-pull fume hood can separate the console from the laboratory, and integral fume hood connects the console with the laboratory as a whole.
Usage skills of fume hood
1, ensure the number of air changes in the laboratory: it is generally believed that the number of air changes in the laboratory should be 6- 12 times/hour. If the fume hood is used as the first-level control of laboratory airflow control, it is usually required to ensure the number of air changes of 4- 12 times/hour.
2. Prevent cross-contamination of air flow: ensure that the air flow in the laboratory is constantly updated to prevent the concentration of toxic gases in the laboratory from increasing on weekdays. The air in all chemistry laboratories should be discharged to the outside and cannot be recycled.
3. Maintain negative pressure: excessive equipment and instruments should be avoided in the fume hood, and the total area of equipment or other equipment in the fume hood should not exceed 50% of the countertop area.
4. Pay attention to the ambient airflow: when the fume hood is close to the doors and windows, the doors and windows should be closed when using the fume hood; Do not turn on the fan near the fume hood to minimize the interference of ambient air flow.