In summer, the temperature is getting higher and higher, especially for saw tooth type greenhouse, so it is necessary to carry out effective air release to ensure the smooth "inhalation" of the greenhouse, and release the air layer by layer. When the greenhouse is closed for 1 hour or the temperature of the greenhouse reaches 20 degrees, a little breeze needs to be released, and the air outlet is as wide as 5cm to improve the photosynthesis of crops and discharge water or harmful substances from the body. When the temperature in the greenhouse rises to the high temperature required by the crops, the secondary air is released to slowly reduce the temperature to a range suitable for the growth and development of vegetables.

When there is no wind or a slight northeasterly wind (or southeasterly wind), the temperature at the western end of the greenhouse is generally 2-3 degrees higher than that in the eastern half, and when the wind is strong, the temperature at the eastern end is 2 degrees higher than that at the western end. When there is northwest or southwest wind, the temperature difference between the two sides of the item will be more than 3 degrees, and the greater the wind, the greater the temperature difference. Due to the different site conditions, the fresh air should be managed in sections.

The thermometer setting should be valid. The key to venting is according to the loading temperature in the thermometer. Whether its accuracy is directly related to whether the hydroponics vegetables are in a natural environment suitable for growth and development. Therefore, it is recommended to set three thermometers symmetrically on the east side of the arch shed, then take the average value to reduce the error, and place the vegetable sprout eye 10 cm above the thermometer. The humidity of the greenhouse environment increases strongly after watering and needs to be dehumidified immediately. Water at noon of the day, close the air outlet moderately, and open the air outlet in the morning to increase natural ventilation. Actual operation for 2-3 days can quickly reduce the environmental humidity of the greenhouse and reduce diseases.