Glass Greenhouse Ventilation Requirements

- May 26, 2017-

The purpose of Glass Greenhouse ventilation is to eliminate the heat and moisture in Glass Greenhouse, adjust the indoor air composition, eliminate harmful gases, and make the environment temperature, humidity and air in Glass Greenhouse suitable for plant growth.

1. Naturally ventilated Glass Greenhouse rely on natural ventilation to regulate the indoor environment for most of the time. The structure of large-scale productive Glass Greenhouse is generally a double slope-facing Glass Greenhouse, and the ventilation form is provided with a ventilation window on the side wall and the roof. The total ventilation area is not less than 15% of the Glass Greenhouse area, preferably greater than 30%. When the roof wind window is open, the sash should be better than the horizontal tilt, the full opening and the horizontal surface to form 100 angle, you can get good ventilation effect. The ventilation capacity of natural ventilation is related to wind speed, wind direction, ventilation window location, ventilation window area and temperature difference inside and outside Glass Greenhouse. When the total area of the ventilation window is 27% of the indoor area, if only the roof ventilation, even if the outdoor wind speed reached 10 km/h, also up to 0 per minute. 75 times ideal ventilation rate; When the roof ventilation window and the side wall ventilation window are fully open, the ventilation rate can reach 0.68 times/min in the case of almost no wind, close to the normal recommended 0.75/min ventilation rate.

2. Forced ventilation Glass Greenhouse although most of the time depends on natural ventilation to regulate the environment, but in the summer when the temperature is higher, especially outside the temperature of more than 33 Shan above the hot weather, the natural ventilation alone is difficult to meet the Glass Greenhouse cooling requirements, the use of forced ventilation and with other measures to cool down is a common Forced ventilation is the use of wind turbines to convert electricity or other mechanical energy into wind energy, forced air flow to the Glass Greenhouse ventilation and achieve cooling effect. The theoretical cooling limit of forced ventilation is that indoor air temperature equals outdoor air temperature. Because, at this time of the Glass Greenhouse inside and outside the temperature difference is zero, ventilation is infinite, in practical application is impossible, due to mechanical equipment and plant physiological reasons, the general Glass Greenhouse ventilation intensity of 0.75 times a minute ~. 5 times, can control the temperature difference inside and outside the Glass Greenhouse within 5 Shan.