Comparison Whirlpool W9 921D OX stainless steel vs Whirlpool W9 931D KS black

The total capacity of the refrigerator is the total capacity of all the main working chambers: refrigerating, freezing, zero, and wine chambers. The set of these chambers, of course, will be different in different models (see more about them above). Here we note that large volumes, on the one hand, simplify the storage of numerous products and, on the other hand, affect the dimensions and price of the unit. It is also worth considering that refrigerators of the same total capacity may differ in the capacity of individual chambers.

Inverter compressors are called compressors that can smoothly change the power of work.

The compressor is a pump that pumps freon through the cooling circuits of the refrigerator. A conventional (non-inverter) compressor has only one power level, and the cooling intensity changes due to periodic switching on and off: the longer the time of continuous operation and the fewer interruptions in operation, the stronger the cooling, and vice versa. Such a design is inexpensive, but it has several disadvantages — in particular, uneven cooling, relatively low temperature control accuracy, and a tendency to create power surges in the network where the refrigerator is connected. Inverter compressors run continuously, while the pump power varies depending on current needs. Thanks to this, refrigerators with compressors of this type are free from the described disadvantages and have some other advantages, such as low noise level and energy efficiency. On the other hand, such units are quite expensive.

Various special features provided in the refrigerator, such as holiday mode, control via smartphone, child lock, ( LED display or TFT display), door alarm reversible door. And now in more detail:

— Holiday mode. A special mode of operation in case of a long absence of users — when there is no foodstuff in the refrigerating chamber and there is no need for the unit to work intensively. In holiday mode, the temperature inside is maintained at about 12 °C; this prevents the growth of mould and unpleasant odours, while the energy consumption is very low.

— Control via smartphone. The ability of access to control the refrigerator via the Internet. The refrigerator, usually, is connected to the World Wide Web using Wi-Fi — via a router or a smart home system. The convenience of this function is obvious: it allows you to control the operation of the unit from anywhere in the world where there is an Internet connection. However, the specific implementation of such control may be different: some models of refrigerators use an application installed on a smartphone or tablet, and others allow you to work through a web page available in any browser. However, the user can thus obtain various data on the unit's operating mode (temperatur...e and humidity in the chambers, the use of special functions, malfunctions and emergencies, etc.) and, if necessary, change its settings.

— Child lock. Various features to keep your refrigerator safe from small children. Often, it means blocking the control panel — so that a curious baby cannot change the settings.

— Display. Refrigerators of any level can be equipped with displays — from the simplest to the most advanced. Anyway, the screen provides additional convenience in operation: it can display various detailed information about the operation of the unit, as well as other useful data (for example, time). But the specific type of display may be different.
— LED display. Usually, they are very simple — they display one colour (maximum two or three basic colours) and a limited set of characters (numbers, individual letters and some special icons). However, such limited functionality is enough even for fairly advanced refrigerators, and LED displays are inexpensive.
— TFT display. These are already the most functional screens — like those used in smartphones, tablets, etc. They are capable to display a huge variety of information and can even be made touch-sensitive. And some units with TFT displays are not just refrigerators at all but multifunctional smart home components. However, such an appliance costs accordingly.

— Door alarm. An alarm system that warns that the refrigerator door is open for a long time (or not closed tightly enough). After some time after opening, such a system gives a signal (usually sound), notifying the user of the need to check the status of the door. It avoids a critical increase in temperature in the refrigerator chamber and damage to the contents. In some models, this system is also complemented by a light indicator that confirms the correct closing of the door — this further reduces the risk of leaving the refrigerator loosely closed.

— Reversible door. The ability to choose from which side the hinges on the refrigerator door will be located and, accordingly, in which direction it will open. It allows you to optimize the space in the kitchen, providing access to the contents of the unit from the most convenient side. Please note that this function is only available for classic design models, including display refrigerators (see “Product type”). In Side-by-Side and French Door refrigerators it makes no sense to provide this feature.

The total capacity of the main working chamber of the refrigerator. If there are separate zero chambers, compartments for wine and other additional functions, this paragraph takes into account only the volume of the refrigerating chamber itself, without additional equipment. In the smallest modern units, this figure does not even reach 100 liters, in the largest it can exceed 400 liters.

The choice of capacity depends on the actual storage needs of the products. At the same time, both the volume of stocks and the frequency of their replenishment (every day, once a week, etc.) matter. The chamber should not be stocked completely; this adversely affects the quality of the refrigerator. On the other hand, it is worth remembering that large volumes accordingly affect the dimensions and price of the unit.

In general, for one or two people, a capacity of 200 – 250 liters, or even less, is considered quite sufficient. The optimal capacity for a family of three is about 250 – 300 liters, for four to five people — 300 – 350 liters, and larger volumes are really needed mainly for specific situations when food has to be stored in large quantities and for a long time.

The ability to fold the shelves will come in handy for placing large-sized utensils, tall or bulky foods in the refrigerator. It can be implemented in completely different ways: by folding the halves of the shelf up or down, using a sliding shelf structure, etc. Some shelves can be folded in several stages: first in half, then they lean against the back wall of the refrigeration chamber.

The capacity of the freezer installed in the refrigerator. Such a chamber is designed to store products at temperatures well below zero (on average -18 °C). Its capacity is related to the total capacity of the refrigerator (and the capacity of the main, refrigerating chamber). However, there is no strict dependence here — models with a similar volume of the refrigerating chamber can be equipped with freezers of different sizes.

When choosing by capacity, it is worth considering how much frozen food you plan to store at a time. Note that it is undesirable to fill the freezer completely — this negatively affects the efficiency of work. However, if this chamber is planned to be used only occasionally, and you do not plan to keep numerous products in it, you can not chase after the capacity: for such cases, 25 – 50 liters, or even smaller capacities, are enough. In the smallest modern refrigerators, the freezer capacity does not exceed 10 liters. And vice versa, very roomy freezers come across — for 176 – 200 liters and even more. Such volumes are typical mainly for side-by-side and French door units (see "Product type"). However, they are also found in models of the classic two-chamber layout.

The number of drawers into which the refrigerator freezer is divided. For top-mounted freezers (see “Freezer”), this paragraph may indicate the number of levels, taking into account the shelves the fridge is equipped (drawers are not used in such chambers).

On the one hand, the abundance of drawers makes it easy to distribute different types of foods in different compartments. On the other hand, more drawers (for the same total freezer capacity) mean less height and capacity for each drawer. So when choosing, you should consider what is more important for you — extensive possibilities for sorting content or the capacity of individual drawers. As for the specific quantity, most modern refrigerators have 3-drawer freezers — this number is generally considered the best compromise between the nuances described above. A larger number of drawers is found mainly in high-capacity units, but 1 – 2 freezer drawers can be found in all types of refrigerators — from small classic to large French Door and Side-by-Side (see "Product type").

The slim shelf is a low (up to 5 cm) tray, which is the best suited for storing seasonings, rolled puff pastry, ice, butter, meat preparations and other small-sized products. In such a container, you can not place products one on top of the other, so finding the needed frozen food will be much easier.

Refrigerator energy class according to the old European standard valid until 2021.

The energy class shows how economical the unit is compared to other models with similar specifications. It is used for devices manufactured before March 1, 2021. Initially, in this standard, classes were designated in Latin letters from A (most economical) to G (high power consumption). However, later improved classes A+, A++, and others appeared. (the more pluses, the more effective is the device). For modern refrigerators, marking A according to the old system is actually the minimum level of energy efficiency specific for outdated and low-cost devices; most models are classified as A + and A ++, and most A+++. There is no need to wait for more pluses. Since 2021, all new equipment will be marked according to the new system, where class G will correspond to the old class A, class F to class A+ and so on.

Note that a higher energy efficiency class (with similar specifications) means a higher price but this difference can quickly pay off due to energy savings.