What Is The General Supply Air Volume of A Fume Hood?

The make-up air volume of the fume hood is a key parameter, which directly affects the air quality in the laboratory and the comfort of the working environment. The determination of the make-up air volume needs to take into account multiple factors, including the exhaust volume of the fume hood, the negative pressure requirements of the laboratory, and the external environmental conditions, etc.

Generally speaking, the make-up air volume is usually about 70% of the exhaust air volume. This is because when the fume hood is in operation, the exhaust fan will extract the air inside the hood, creating a certain negative pressure area. In order to maintain the air circulation and balance in the laboratory, it is necessary to introduce fresh air through the make-up air system to replenish the air that has been drawn away. If the make-up air volume is too small, it may lead to excessive negative pressure in the laboratory, affecting the comfort and work efficiency of the laboratory personnel. If the make-up air volume is too large, it may increase energy consumption and noise, and may also have adverse effects on environmental parameters such as temperature and humidity in the laboratory.

However, it should be noted that this 70% proportion is not absolute. In practical applications, the size of the supplementary air volume still needs to be adjusted according to the specific conditions of the laboratory. For instance, if the laboratory has higher requirements for negative pressure, it may be necessary to appropriately increase the supply air volume to maintain a more stable negative pressure environment. Conversely, if the laboratory does not have a high requirement for negative pressure or the exhaust air volume itself is small, then the make-up air volume can also be reduced accordingly.

In addition, the adjustment of make-up air volume also needs to take into account the ventilation efficiency and air change rate of the laboratory. Generally speaking, the higher the ventilation efficiency and air change rate of a laboratory, the greater the demand for supplementary air volume. Therefore, when determining the make-up air volume, it is also necessary to comprehensively consider factors such as the design of the laboratory's ventilation system, the performance of the exhaust equipment, and the actual needs of the laboratory personnel.

Overall, the make-up air volume of a fume hood is a parameter that needs to be flexibly adjusted according to the actual situation. When determining the make-up air volume, factors such as the negative pressure requirements of the laboratory, ventilation efficiency and air change rate should be fully considered to ensure the air quality in the laboratory and the comfort of the working environment.