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The air volume hood is in hand, and the balance test of the ventilation system can also be carried o

日期:2024-05-20 04:45
浏览次数:284
摘要:Everyone in the industry knows that the air flow hood is mainly composed of three parts: the air flow hood body, the base, and the PDA. It is mainly used to collect the air flow and gather the wind to the basic air velocity homogenizer. When doing the clean room acceptance test, the air volume test is the first item to be done. Only when the clean room air volume is qualified, can the next item test be started. Before air volume detection, it is necessary to check whether the fan is operating no
Everyone in the industry knows that the air flow hood is mainly composed of three parts: the air flow hood body, the base, and the PDA. It is mainly used to collect the air flow and gather the wind to the basic air velocity homogenizer. When doing the clean room acceptance test, the air volume test is the first item to be done. Only when the clean room air volume is qualified, can the next item test be started. Before air volume detection, it is necessary to check whether the fan is operating normally, whether the components of the system are installed correctly, and there are no obstacles, and all valves should be fixed in a certain open position. When using an anemometer to test the air volume in the pipeline, you should measure whether the size of the air duct and the air outlet meet the design requirements. In principle, the position of the measuring point should be selected in a place where the airflow is relatively stable and uniform, and no less than 3 times the air duct before the local resistance component. The diameter or length of the long side shall be no less than 5 times the diameter or length of the long side of the duct after the local resistance component.

Air flow hood


  working principle:
A wind pressure sensor is installed on the uniform wind speed, the sensor reflects the change of the wind speed, and then calculates the air volume according to the size of the base. The display of the air volume cover adopts PDA, and the large-screen LCD display is intuitive, and the data of wind speed, temperature and air volume can be directly obtained, and the recording time interval can be set for continuous parameter recording for data analysis. The measured and recorded data is recorded on the memory card and will not be lost, and the data can be transferred to the PC through the serial port of the computer for further application.
The advantages of using the air flow hood to test the balance of the ventilation system are: direct reading of the air flow, quick measurement and easy operation. However, the design of the HVAC/R system will affect the test. Factors that need to be considered include: the type of diffuser or air outlet, the distribution of upstream airflow (elbows, fans), the influence of duct resistance (changes in duct area), the physical characteristics of the air and the shape and size of the air flow hood. In order to improve the test, the on-site calibration K factor can be used to compensate for non-standard test conditions.

Upgraded air volume hood

Air flow hood accessory bracket


Scope of application:
The airflow at the tuyere in the centralized air-conditioning system is more complicated, and the measurement is more difficult. Only when it cannot be measured at the branch pipe can it be measured at the tuyere. Generally, the tuyere air volume hood and tuyere wind speed method are used.
Compared with the tuyere wind speed method, the wind flow hood can quickly and accurately measure the average ventilation rate of the tuyere. Whether it is installed on the ceiling, wall or ground, the sending, returning, and exhausting vents, equipped with corresponding sensors can directly read the wind speed, pressure and Relative temperature and humidity, especially suitable for diffuser-type air outlets. When in use, the hood is close to the ceiling surface, so that the tuyere is completely contained and can be read directly.