Direct cooling and air cooling are two different cooling methods. They have their own advantages and disadvantages, and their application scenarios are also somewhat different.
Direct cooling adopts the cooling method of natural convection of air, and the evaporator realizes cooling by absorbing the heat in the food and the air through heat conduction. The cooling pipes are directly fixed around the refrigerator to achieve overall cooling, that is, direct cooling.
Advantage
1. Direct cooling type cold storage has simple structure, relatively low failure rate and cheaper price;
2. The temperature evaporates slowly. If the unit fails in a short time, the original temperature can be maintained in the warehouse for a short time, and the impact on the goods is small.
Shortcoming
1. The problem of frosting causes users to manually defrost, which is time-consuming and labor-intensive;
2. The frosting problem will seriously affect the heat absorption and refrigeration of the evaporator, and the refrigeration efficiency will be significantly reduced;
3. Natural convection makes the cold storage distribution uneven, there are dead spots in the cold storage, the degree of freezing of the food is not the same, and the cooling effect is poor;
4. The refrigeration is slower, because according to the characteristics of the pipeline, the refrigeration speed is a little slower;
5. The humidity of the air is high, which may cause the food in the freezer to stick and freeze together, making it difficult to separate.
Air cooling is the use of air for cooling. When high-temperature air flows in the built-in evaporator (away from the inner wall of the refrigerator), due to the high air temperature and the low temperature of the evaporator, the two directly exchange heat, and the air temperature gradually decreases. At the same time, cold air is blown into the refrigerator through a fan, thereby reducing the temperature.
Advantage
1. Air-cooling will not form frost on the inner wall of the freezer, avoiding the trouble of manual defrosting, saving worry and effort, and the cooling effect is better if there is no frost attached to the refrigerator;
2. The refrigerating air is forced to circulate by the fan, the air-conditioning distribution is more balanced, and the effect of food freezing and refrigeration is better;
3. The refrigeration is fast, and the air cooler can quickly refrigerate, so that the temperature in the warehouse can quickly reach the temperature required by the goods;
Shortcoming
1. Compared with direct cooling, the air-cooled structure is more complicated, with more parts, and the failure rate is relatively high;
2. In order to realize the circulation of cold air, the fan has a heavy workload, and the automatic defrosting will also increase the energy consumption, so the power consumption is relatively large;
3. The cargo of the air outlet of the air-cooled refrigerator with simple structure is easy to be blown dry and lose moisture.
Reasons why air-cooled refrigerators are more popular
Automatic defrost
Since the evaporator of the freezer is not in direct contact with the food, the evaporator can be heated for a short time through the heating system, and the refrigeration will be restored immediately after defrosting. The temperature fluctuation in the freezer is very small, which is convenient and does not affect the quality of food refrigeration.
Clean and refreshing
The inside of the frost-free freezer is clean and fresh. Its cold air system will take away excess water in the box during the cooling process, so there will be no frost, and the food will not freeze together when it is frozen. In addition, the continuously circulating cold air is filtered by the deodorizing system to keep the smell in the freezer fresh for a long time, greatly reducing the phenomenon of mutual odor between foods.
Uniform cooling
The refrigeration system of the cold air system is like installing an air conditioner in a freezer, the cold flow enters all the holes, and the temperature in the freezer is stable and uniform. The direct freezer is directly cooled by natural convection, just like putting a piece of ice in the freezer, the food near the evaporator will be very cold, and in some places far away from the evaporator, it is easy to form freezing dead corners and spoil the food.
Precise temperature
The temperature of the frost-free freezer is uniform, the temperature of the temperature control point is the temperature at any point, and the temperature in the freezer is very accurate. However, due to the existence of dead corners in the direct-cooling freezer, the temperature of the temperature control point is often a few degrees different from the actual temperature, which affects the quality of food preservation.
Post time: Nov-18-2021