... down the temperature and increase the humidity.1.Working principleThe air inside the greenhouse is drawn out by the exhaust fan ... is at last reduced. 2.MaterialA.The cooling pad is made of strengthened kraft paper, excellent water keeping effect. TypeThickness (mm)Height ... ,2000300,6007W5090100,150,200,3001500,1800,2000300,6005 greenhouse evaporative cooling pad wet curtain