Glass greenhouse

A glass greenhouse refers to a greenhouse that uses glass as the lighting material and belongs to a type of greenhouse. In cultivation facilities, glass greenhouses, as a form of long-term use, are suitable for use in various regions and climatic conditions. There are different construction models in the industry based on the size of span and bay, and they are also divided into vegetable glass greenhouses, flower glass greenhouses, seedling glass greenhouses, glass greenhouses, research glass greenhouses, three-dimensional glass greenhouses, irregular glass greenhouses, leisure glass greenhouses, glass greenhouses, and so on. The winter heating problem of glass greenhouses can be solved through various heating methods, with acceptable energy consumption costs.

Glass greenhouse ventilation

The main purpose of ventilation in a glass greenhouse is to reduce the waste heat and moisture inside the greenhouse, adjust the air composition inside the greenhouse, reduce harmful gases, and make the environmental temperature, humidity, and air conditions inside the greenhouse suitable for the requirements of plant growth.

1. Natural ventilation glass greenhouses rely mostly on natural ventilation to regulate the indoor environment. The structural form of large-scale production glass greenhouses is generally a double slope multi-span greenhouse, with ventilation windows installed on the side walls and roof ridges. The total ventilation area shall not be less than 15% of the greenhouse area and greater than 30%. When the ridge wind window is opened, the window sash can tilt upwards through the horizontal plane, and when fully opened, it forms a 100 angle with the horizontal plane to obtain good ventilation. The ventilation amount of natural ventilation is related to wind speed, direction, position and area of ventilation windows, as well as the temperature difference inside and outside the greenhouse. When the total area of ventilation windows is 27% of the indoor floor area, if only the roof ridge ventilation is used, even if the outdoor wind speed reaches 10 kilometers/hour, it cannot reach 0 75 ideal ventilation rates; When the roof ridge ventilation windows and side wall ventilation windows are fully open, the air change rate can reach 0.68 times/minute even in the absence of wind, which is close to the normal 0.75 times/minute air change rate.

2. Although forced ventilation glass greenhouses mostly rely on natural ventilation to regulate the environment, during high summer temperatures and hot weather with outdoor temperatures above 33 ℃, when relying solely on natural ventilation greenhouse cooling requirements, using forced ventilation and other measures for cooling is a commonly used method in production. Forced ventilation is the use of fans to convert electrical or other mechanical energy into wind energy, forcing air flow for greenhouse ventilation and cooling. The theoretical cooling of forced ventilation is that the indoor air temperature is equal to the outdoor air temperature.