Comparison between negative pressure fans and positive pressure ventilation: Which one is more suitable for your production environment?

1. Working principle
Negative pressure fan: uses atmospheric pressure to discharge air from one place to another, thus forming a negative pressure area indoors. When the negative pressure fan is working, the outdoor air automatically flows into the room through the air inlet, forming a convection cycle to achieve ventilation.
Positive pressure ventilation: a system that drives the discharge of indoor dirty air by providing fresh air to the room to form a positive pressure environment. The positive pressure fan drives the fan blades to rotate through the motor to generate a strong airflow, and sends the outdoor fresh air into the room after filtering and purification. At the same time, the indoor air pressure gradually increases to form a positive pressure state, so that the dirty air is naturally squeezed to the low-pressure area such as the gap between doors and windows for discharge.
2. Applicable scenarios
Negative pressure fan:
Applicable to occasions that require ventilation and exhaust of harmful gases or dust, such as factory workshops, laboratories, hospital operating rooms, etc.
Particularly suitable for handling dust, because blowing inward easily makes dust fly, and negative pressure fans can effectively avoid this problem.
During high temperatures in summer, negative pressure fans can also quickly remove hot air and moisture from the room and lower the indoor temperature.
In emergency situations such as fires, negative pressure fans can be used as smoke extraction systems to reduce the harm of toxic gases to the human body.
Positive pressure ventilation:
Suitable for occasions where air flow needs to be controlled and external pollutants need to be prevented from entering, such as air conditioning systems in high-rise buildings, underground parking lots, etc.
It can effectively improve indoor air quality and remove exhaust gas, odor, moisture and heat.
The equipped air filter can prevent harmful substances such as dust and bacteria from entering the room, reducing the risk of germ transmission.
Energy-saving and environmentally friendly, it can more effectively control indoor temperature and reduce air conditioning energy consumption.
3. Performance characteristics
Negative pressure fan:
It is large in size and has the characteristics of super large air duct, super large fan blade diameter, and super large exhaust volume.
Energy-saving and low-consumption, low power consumption, usually about 10% to 15% of traditional air conditioners.
Environmentally friendly, does not contain Freon (CFC).
Good cooling effect, can effectively reduce indoor temperature.
Positive pressure ventilation:
Forced air supply, can quickly deliver fresh air into the room.
The equipped air filter can ensure the quality of the air delivered to the room.
The air intake can be adjusted according to the indoor population density, outdoor temperature and other conditions to keep the indoor air fresh and comfortable.
IV. Noise and vibration
Negative pressure fan: Since the air needs to be discharged from one place to another, noise and vibration control need to be considered during design.
Positive pressure ventilation: When the air supply volume is large, it may generate a lot of noise, but the noise impact can usually be reduced through reasonable noise reduction measures.