As the optimum temperature for most crops is usually below 30 degrees, the internal temperature of agricultural plastic  greenhouse for tropical crops should not exceed 35 degrees, and that for hardy or shade-loving crops should not exceed 25 degrees.  But for most of the country's low sea wave areas after May the temperature will be more than thirty degrees, intelligent greenhouse greenhouse without the use of shading and cooling equipment, the temperature will be as high as forty or fifty degrees, not suitable for the growth of any crops.  Today, I would like to share with you some of the installation points of the most important cooling system in summer: fan water curtain.  

First, temperature gradient design  
The temperature gradient difference between the fan and the water curtain should not be more than four degrees.  This needs to design fan water curtain exhaust distance should not exceed 48 meters.  Because the exhaust effect beyond the exhaust distance of the fan is reduced, the temperature of the air inlet of the water curtain is low, and the temperature of the air outlet at the fan location is high.  
Two, Cooling Pad &Fan System principle  
1. The fan starts to pump air outward to produce negative pressure outdoor air through the water film of the water curtain to evaporate and absorb heat to cool down.  So there are two main functions the first is the ventilation function, the second is the evaporative cooling function.  

2. The cooling principle is that humidity increases and the temperature decreases.  Therefore, the cooling effect is good in north China, and the effect is worse in high humidity areas.  

Three, Cooling Pad &Fan System layout need reference data  
1, the number of fans, which is related to the intelligent greenhouse internal ventilation volume.  
2. The area and height of the water curtain are related to the heat absorption effect of evaporation.  
3, the water volume and head of the pump.  The length of water curtain for a normal pump should not exceed 40 meters.  
4. The size of the reservoir is related to the water supply.