Capacity
It is the total working capacity of the freezer. A larger capacity allows you to accommodate more products but affects the dimensions and cost of the unit. Therefore, when choosing according to this parameter, you should not chase after the maximum capacity but the capacity you really need. For example, the average required capacity is 50 litres per person. And when choosing a display chest freezer (see "Product type"), you need to take into account the number of products offered for sale.
It is also worth considering that the freezer is often divided into several compartments (see below) - which means that a large capacity does not guarantee that large pieces of food can fit in the device.
No Frost
No Frost system inside the freezer. A special fan provides air circulation, while moisture condenses in the frost, not in the working chamber, but in a special compartment. Periodically, the fan turns off, the frost melts, and the meltwater flows into a special tray, from which it evaporates. Such a system eliminates the need to defrost the freezer to remove frost periodically. On the other hand, it imposes special requirements on the packaging of products, since in such freezers the products dehydrate fast.
Number of compartments
it is the number of compartments provided in the design of the freezer. In some models, it is possible to set different temperatures for different compartments. It is worth noting that a large number of boxes does not always mean maximum convenience, since, with an increase in their number, the volume of each individual box inevitably decreases.
Minimum temperature
The lowest temperature that the freezer can maintain in normal operation. First of all, the duration of food storage in the freezer depends on this parameter: it is believed that a temperature of -12 ° C is enough to preserve food for a month, -18 ° C – 3 months, -24 ° C – up to a year. At the same time, it must be taken into account that not only temperature affects the shelf life but also the type of product and its quality before freezing.
Power failure autonomy
The amount of time the freezer keeps food cold enough when the refrigeration system is turned off, for example, due to a breakdown or power outage. Technically, the power failure autonomy for each model is calculated differently; For example, for a freezer with an operating temperature of -18 ° C, this is the period during which the products in the chamber heat up from -18 ° C to -9 ° C. To sum up, the time is indicated during which the frozen products are guaranteed not to heat up to a temperature at which they could lose their properties.
Freeze capacity
One of the main indicators of freezer performance is the approximate amount of fresh food that the freezer can completely freeze from room temperature to the minimum operating temperature in 24 hours. For domestic use, a power of 10-15 kg/day is considered quite sufficient. More performant models may be required if you have to freeze a lot of food at a time or for industrial purposes.
Fast freeze
It is the forced freezing mode, in which the temperature inside the freezer is briefly reduced to -24 °C. This mode is intended for the case when you need to freeze numerous products at the same time — without a sharp decrease in temperature, the heat from numerous non-frozen products could lead to its critical increase.
Usually, the fast freeze mode must be turned on in advance — 5 to 6 hours before loading the products. Thus the freezer has time to decrease the temperature in the chamber. In this case, it is necessary to take into account the increased load on the compressor — it is impossible to turn on fast freeze for a long time. In some models, automatic shutdown of the fast freeze mode is provided. In some, it must be done manually.
Lighting
Freezer interior lighting system. This function is very helpful given that the working chamber of the unit, even with the door open, is often shaded, and it is not so easy to see its contents. The lighting usually works automatically — similar to how it is implemented in refrigerators: the light turns on when the door is opened and turns off when it is closed.
Door alarm
It is a system that monitors the closing of the freezer door. If the door is not closed for a long time or is not closed tightly enough, an audible or light (depending on the model) signal is given. It helps to avoid a critical increase in temperature in the working chamber and preserves the quality of the products.