What are the changing patterns of temperature in fruit tree greenhouses?

The changing pattern of greenhouse temperature: The temperature inside the greenhouse changes due to changes in sunlight or heating. If it is a heated greenhouse, the temperature inside the greenhouse can rise quickly during heating. When not heated, the daytime temperature in the shed is mainly related to the outside weather conditions.

If it’s a sunny day and the greenhouse is closed, the temperature will rise quickly, reaching as high as 40 to 50 degrees Celsius or more. Even in the cold winter, the outside temperature is around 0℃; as long as it is sunny, the temperature inside the shed can still reach above 20℃, or even above 30℃. On cloudy days, especially continuous cloudy days or rainy and snowy weather, the warming effect of the greenhouse without heating is poor. The difference between the daytime temperature inside the shed and the temperature outside the shed is small.

The unheated single-layer plastic shed covered with film is, firstly, related to the structure of the shed and its management conditions; secondly, it is related to the changes in daily temperature and seasonal temperature outside the shed, and there are obvious seasonal temperature differences and large The temperature difference between day and night. Such as low temperatures in winter and early spring. Another example is that on a sunny day, the temperature in the shed is the lowest from midnight to early morning before sunrise. After sunrise, due to the influence of solar radiation, the effect of the shed is enhanced, and the temperature inside the shed rises. The highest temperature is often from 11 am to 1 pm. After 2 pm, the temperature began to drop. At night, the lowest temperature inside the shed is 1 to 3°C higher than outside the shed. These changes are very obvious and dramatic in sunny, less cloudy, and sunny weather. On cloudy and rainy days, when solar radiation is weak, the temperature inside the shed changes relatively slowly.

If the structure of the plastic shed is unreasonable or poorly managed, the temperatures inside and outside the shed may be similar.

The temperature inside the shed also varies depending on the location. For example, the horizontal distribution is: high in the middle and low on both sides. For vertical distribution, under sunlight during the day, the temperature at the top of the shed is high and the lower part is low; the opposite is true at night or on rainy days. For a shed built on a slope, the temperature is higher on the uphill slope and lower on the downhill slope.