答：負壓風機工作原理是：負壓風機的主要工作原理是利用空氣對流，達到通風換氣的目的。風機運轉后，利用風機的轉動，將室內悶熱的氣體排出室內，將室外新鮮的空氣吸入室內。在一定空間范圍內，合理的安裝風機，通風換氣的效果可以達到90%以上，是一些大型場所，例如工廠車間廠房、各種大棚、養殖場以及其他大型場所理想的通風換氣設備。

Q: what is the working principle of the negative pressure fan?

Answer: the working principle of the negative pressure fan is: the main working principle of the negative pressure fan is to use air convection to achieve the purpose of ventilation. After the fan is operated, the rotation of the fan is used to discharge the indoor hot gas and suck the outdoor fresh air into the room. Within a certain space, the reasonable installation of fans can achieve a ventilation effect of more than 90%. It is an ideal ventilation equipment for some large places, such as factory workshops, greenhouses, farms and other large places.