1. Greenhouse effect and soil heat converter effect: The heat energy of the solar greenhouse comes from sunlight radiation energy, and sunlight radiation during the day. In the form of short-wave light, it passes through the transparent covering of the greenhouse and enters the greenhouse. Most of it is absorbed by the soil, walls, columns, back walls, back roofs and vegetable crops, which increases the temperature of these materials and converts sunlight energy into heat energy. This is the heat exchanger effect of greenhouse soil and greenhouse building materials. This heat energy is then spread out through long-wave radiation, conduction, convection, etc. This long-wave radiation is absorbed by the air, increasing the temperature in the greenhouse. 2. Greenhouse heat balance: The heat in the soil will also be conducted to the cooler soil outside the greenhouse and to the lower soil. The hot air inside the greenhouse heats the front roof membrane, which then loses the heat in the form of long-wave radiation. The greenhouse both heats up and dissipates heat during the day, but only dissipates heat without increasing the temperature at night. If the greenhouse obtains more heat and loses less heat, the greenhouse will heat up. If the greenhouse receives less heat and loses more heat, the greenhouse will cool down. This is the balance of the greenhouse. Insulation design is to reduce heat loss. 3. Insulation design: The span of the greenhouse is an important factor in determining the insulation performance of the greenhouse. The distance from the front corner of the greenhouse to the back wall of the greenhouse is the span of the greenhouse. The size of the span is related to the type and height of the greenhouse. A reasonable height-to-span ratio should be above 0.5. In areas with 40° north latitude, a span of 6 meters is appropriate, and in areas south of 40°, a span of 7 meters is appropriate. In order to reduce heat release in the greenhouse, it is best to use building materials with low thermal conductivity. It is best to use an earth wall. If a brick wall is used, the gap should be left in the middle or filled with leftovers. When building a greenhouse, it is most reasonable to use heterogeneous composite walls for the walls, and materials with large heat absorption coefficients, such as stones and bricks, for the interior walls to increase the wall's ability to absorb and store heat, so that the temperature of the greenhouse at night does not change. Will be too low; use materials with good thermal insulation properties for exterior walls, such as hollow bricks or adobe, to prevent heat loss. The most economical method is to use rammed earth walls or grass mud walls, which have good results. The thickness of the wall of the solar greenhouse should reach the thickness of the local frozen soil layer. If it cannot be reached, soil can be built outside the wall, or a wind barrier can be added outside the wall, and random grass and rice husks can be filled between the wall and the wind barrier. etc. The general requirement is that the inside of the wall should not be frosted. ?