The dividing line between air-cooled and direct-cooling refrigerators is around 300 liters. Larger capacity, multi-compartment air-cooled refrigerators have an advantage.
With larger capacity and more compartments, air-cooled refrigerators have a clear advantage in cooling distribution. Direct-cooling refrigerators face technical obstacles and are very difficult to implement. Three compartments are the basic limit for direct-cooling refrigerators; adding more compartments will sacrifice some performance. Therefore, don't be fooled by some large-capacity, multi-compartment (even drawer-door) direct-cooling refrigerators on the market. These products are not uncommon, mostly from smaller brands, mainly sold in third- and fourth-tier markets. They can also be found in the suburbs of some large cities and in appliance wholesale markets.
Because of the fan, air-cooled refrigerators have a more even internal temperature with less temperature fluctuation, resulting in better cooling performance. However, considering the fan's function and complex circuit design, air-cooled refrigerators consume significantly more energy and are noisier than direct-cooling refrigerators.
Direct cooling refrigerators, lacking a fan, generate no additional noise or power consumption, and also prevent food from drying out due to airflow.
Air cooling, with its forced circulation of cold air, offers faster cooling and better temperature uniformity-an inherent advantage that direct cooling cannot match. Direct cooling, relying on natural convection, suffers from less uniform temperature distribution and a slower cooling speed.
Air cooling's inherent defrosting cycle, fan, and multiple internal compensation heaters result in higher power consumption and noise levels compared to direct cooling refrigerators. Therefore, under similar conditions, air cooling is clearly inferior in these two aspects. A comparison of national and international refrigerator performance and energy efficiency standards clearly demonstrates this. Claims that air cooling consumes less energy and is quieter than direct cooling are based on comparisons made under different conditions.
The manual defrosting process in direct cooling is indeed annoying. The so-called "micro-frost design" simply uses a single drawer for the freezer to reduce airflow and frost buildup. Even so, defrosting is generally needed every six months. This can be extended if the door is opened infrequently, and shortened otherwise. If the door seal is faulty or worn, frost buildup will worsen. The frequency of defrosting will increase with prolonged use.
Because frost-free refrigerators use forced air circulation, odors will circulate throughout all compartments. Dual-system frost-free refrigerators are becoming more common, separating the freezer and refrigerator compartments, which helps.
Frost-free refrigerators constantly carry moisture from inside the refrigerator to the evaporator, which then drains away during defrosting, leading to dehydration and hindering freshness preservation. This is an inherent drawback of frost-free refrigerators. Although some so-called preservation technologies exist, they only prevent cold air from entering a small area (such as a relatively sealed space), allowing it to flow only from the sides. The space is essentially close to natural convection, but it's just direct cooling in a small space.
