At present, there are still many old sheds in some vegetable growing areas. Although the sheds are old, they are also a major pillar of vegetable farmers' economic income. These old sheds have poor thermal insulation performance due to their low height and insufficient wall thickness. Therefore, it is very important to maintain or improve the thermal insulation capacity of the solar panel greenhouses in winter.
Insulation film around the shed
In winter, most vegetable farmers take measures to add a covering layer, and most vegetable growers use a film as a covering layer. Some also fill the space formed by the wall and the shed with corn stalks. Generally speaking, the use of film covering can not only prevent the temperature in the shed from losing too quickly, but also prevent the erosion of the outside of the wall such as precipitation. Under normal circumstances, the film should cover the rear roof and the rear wall together to form a relatively complete thermal insulation covering layer.
Front face covered with double protection
The front face of the shed is also a key area for temperature leakage. Because the front face cover is easily eroded by the moisture on the ground and the overflow of moisture after the shed film is damaged, the cover ages too fast and it is easy to freeze in winter, which makes the front face insulation Sexual decrease. Vegetable farmers usually take measures to add mulch, and the mulch used is mostly old straw curtains, non-woven fabrics, etc. The reporter learned during an interview in Jiyang County, Shandong Province that many vegetable farmers use double-layer covering, that is, the inner layer is covered with a film, and then old straw curtains, non-woven fabrics and other coverings are added to the film. The double-layer covering can not only prevent moisture from invading the shed surface covering, but also prevent the excessively fast loss of the front face temperature and ensure the stability of the shed temperature.
Set up a well-sealed buffer room at the door
The current new types of large sheds all open access channels from the back wall, and build huts for living or storage facilities outside the sheds, and set shed films or cotton cloths at the channel openings to block cold air from directly entering the sheds and causing damage to the vegetables. But the old shed does not have these measures. Generally, the doorway of the old shed is mostly opened from the front face of the big shed. When you open the door, you will see the vegetables. In winter, the air exchange is frequent at this place at the door, and the temperature is generally low, so the vegetables at the door often do not grow very well.
Therefore, the door of the old shed must be equipped with a buffer room, and the buffer room cannot be surrounded by a piece of film, but must be sealed. It is recommended that the top of the film used as a buffer room should be fixed on the steel wire on the surface of the shed, in contact with the shed film. If the height cannot be reached, it is recommended to use a softer ground film connection between the film and the greenhouse film. In a word, the buffer room should be sealed as well as possible, otherwise it will not function as a buffer.
A windshield film is also required under the air vent
The interview found that some old sheds did not have a windshield film under the air outlets. Asking the reason, vegetable farmers mostly did not install it because the corridor was at the front face of the shed and the back wall was inoperable. The windshield film has many advantages. On the one hand, it can adjust the air circulation to prevent cold wind from blowing directly on the vegetables and avoid fruit cracking. On the other hand, the windshield can block water droplets and debris from the air outlet, and avoid vegetable leaves near the back wall. Covered by debris affects photosynthesis.
The back section must be waterproof
The roof of the old shed is low, and the cement pillars are rarely used for post-cutting, and wooden sticks are mostly used. If the back roof of the old shed enters into water and rots and collapses, this situation is more difficult to deal with. Therefore, the old shed should be waterproofed from the outside of the rear roof. It is recommended that after the film on the upper part of the air outlet is replaced, a new film should be laid back and covered with a non-woven fabric for protection. Then install the straw curtain.