What are the cooling methods for multi-span glass greenhouses

Venlo glass greenhouses generally have an area of several thousand to several ten thousand square meters, and the cost is between several hundred thousand and several million. The building structure of Venlo glass greenhouse should be sealed to keep warm, but it should be convenient for ventilation. For the construction of vegetable greenhouses, we should choose a suitable location, which should be built to avoid wind and sunrise, fertile soil, good light and infiltration conditions. But for the hot summer, we still need to cool down properly. Today we are talking about cooling methods for glass greenhouses.

Advantages of multi-span glass greenhouse

﹙1﹚High light transmittance, uniform illumination

Due to the characteristics of the load-bearing structure, the roof of the Wenluo glass greenhouse uses glass with high light transmittance as the lighting material. At the same time, special aluminum profile is used as the roof beam, which greatly reduces the cross-sectional size of the roof beam, saves the cross-sectional size of the roof beam, reduces the sun shading of the entire roof system, and greatly improves the light transmittance of the entire greenhouse.

﹙2﹚The greenhouse is well sealed

The glass greenhouse adopts special aluminum alloy, matching rubber strips and injection molded parts as the glass components, which greatly improves the sealing performance of the greenhouse. On the one hand, the good original tightness ensures that the heat loss caused in the greenhouse is greatly reduced.

﹙3﹚Large ventilation area

The roof structure of Venlo glass greenhouses requires a relatively high proportion of reduced ground projections. Compared with other types and greenhouse technologies of the same time span, there can be 2 to 4 pairs of roofs in each span, that is, 2 to 4 roof ridges and gutters. .

Cooling method of glass greenhouse:

1 Shading and cooling: Use opaque or low light transmittance materials to shading and cooling to prevent excessive solar radiation from entering the greenhouse, which not only ensures the normal growth of crops, but also reduces the temperature of the greenhouse. Due to different shading materials and installation methods, the temperature of the greenhouse can be reduced by 3℃～10℃. Shading methods include indoor shading and outdoor shading. The indoor shading system is a supporting system connected to the frame of the glass greenhouse with metal wire or plastic mesh, and the shading net is installed on the supporting film line. Generally use electrical control or manual control. The outdoor shading system is to install a shading framework outside the greenhouse framework and install a shading net on the framework. The sunshade net can be driven by a curtain-drawing mechanism or a film-rolling mechanism, and can be opened and closed freely. The sunshade net is installed outdoors and has a good cooling effect, which can directly block the solar energy in the greenhouse, and all kinds of sunshade nets can be used.

2. Evaporative cooling: Evaporative cooling is the use of hot water to cool the unsaturated air in the glass shed to evaporate the potential. When the moisture in the air is not saturated, the water will evaporate into water vapor and enter the air. When the water evaporates, it absorbs the heat in the air, reduces the air temperature and increases the air humidity. The evaporative cooling process must ensure the air flow inside and outside the glass greenhouse, discharge the greenhouse high temperature and high humidity gas out of the greenhouse, and supplement the fresh air, so it is necessary to adopt the method of forced ventilation. At present, the methods of evaporative cooling are wet curtains, fan cooling and spray cooling.