Why should the vending machine of Guangdong lattice machine manufacturer install an air barrier?

Due to different temperatures on both sides of the envelope structure of the vending machine, Guangdong lattice machine manufacturers, along with heat transfer, also occur when moist air flows. This movement of water is called water vapor penetration. It is difficult to block water vapor penetration. It is even more difficult than blocking the heat flow. The temperature difference between the two sides of the envelope structure will cause the partial pressure difference of water vapor, thereby forming the ability of water vapor permeation. For example, the outer side of the vending machine is 30°C, the partial pressure of water vapor at 60% relative humidity is 19.09mm Hg, and the low temperature side is 0°C, even when the relative humidity is 100%, the partial pressure of water vapor is only 4.58mm. column. In this way, the partial pressure of water vapor on both sides of the enclosure structure is (19.09mm Hg -4.58mm Hg) 14.51mm Hg, which is a considerable driving force compared to an ordinary fan with a pressure head of 30-60mm Hg ——Because of this driving force. The water vapor can be forced through the cracks of the tiny pores of the enclosure structure into the vending machine. For low-temperature vending machines, it means that the moisture pressure enters the enclosure structure and the insulation layer. It has extremely adverse effects on the heat preservation of the vending machine body. Because the thermal conductivity of ice is 2.0W, which is about 100 times greater than the thermal conductivity of polyurethane of 0.02W, it will damage the thermal insulation layer in severe cases. Therefore, in order to ensure that the thermal insulation material maintains good thermal insulation performance, prolongs the service life, and maintains the normal use of the vending machine, it is very important to provide a moisture-proof and gas-barrier layer on the surface of the thermal insulation layer. It is especially important for Guangdong lattice machine manufacturers to use modified atmosphere vending machines, because in addition to the water vapor entering the shell structure is not conducive to thermal insulation, it will also cause changes in the gas in the vending machine, and it is also not conducive to fruits and vegetables. Storage. Driven by the partial pressure difference of water vapor, the water vapor outside the vending machine will penetrate into the vending machine. When water vapor penetrates into the envelope, when the cold air reaches the air barrier at the dew point or freezing point temperature, the water vapor will condense into water droplets or ice crystals in the gap between the gap and the insulating material, causing the damping of the insulating material to reduce the insulation performance. Previous: Guangdong lattice machine manufacturer! How much is the unmanned vending machine Next: How can Guangdong lattice machine manufacturers improve the operational efficiency of vending machines?