What kind of glass is used in supermarket freezers?

Freezers are a highly practical electrical appliance commonly seen in our daily lives. They play an essential role in refrigerating food regardless of the season. Compared with the old-fashioned freezers with opaque lids that concealed everything inside, the modern ones equipped with transparent glass doors appear neat and fresh, while also making it easier for customers to browse and select products.

However, many people have questions about this kind of glass: what type of glass is it? Why does it not fog up? Is it easy to break? Can it be replaced with ordinary flat glass? We will answer these questions one by one below. First, it can be confirmed that freezer glass is not ordinary flat glass. Freezer glass is generally made of hollow glass with LOW-E coated glass, which greatly enhances its thermal insulation performance. Meanwhile, inert gases such as argon are filled into the hollow layer. This further prevents the cold air inside the freezer from transferring to the outer surface of the glass, which would otherwise cause the temperature of the outer glass surface to drop. When the temperature falls below the dew point temperature of the air outside the freezer, condensation would form, obstructing customers' view.

At present, some freezers also use electrically heated glass made with heating wires or heating films. Unlike heating wires, heating films are not only easier to produce but also ensure more uniform heating across the glass surface. They can handle normal fluctuations in the conventional operating voltage without overloading. The main function of electrically heated glass is to raise the temperature of the outer glass surface, keeping it above the dew point temperature of the air and thus preventing condensation. It is mostly used in the production of freezers. Finally, the glass doors of freezers are generally processed with tempered safety glass technology. This type of glass has excellent impact resistance and can withstand considerable external force without breaking. Even if it does break, it will not shatter into large, sharp fragments that could harm people or damage property. It also boasts outstanding thermal stability, capable of withstanding temperature changes of up to 300 degrees Celsius.

Therefore, the glass doors of freezers are shatter-resistant, fog-free, and cannot be replaced with ordinary flat glass. Whether in terms of thermal insulation, energy efficiency, impact resistance or low-temperature resistance, ordinary flat glass simply fails to meet the required performance standards.