Hot water tank volume
The volume of the hot water tank provided in the device.
This parameter describes the maximum amount of hot water that the cooler can produce in one run, without interruption or with minimal interruptions. When this amount is exhausted, you will have to wait until the water in the tank heats up again to a sufficient degree; the waiting time depends on the heating capacity (see below). At the same time, the volume of hot water tanks in modern devices is usually several litres, and it is extremely rare to drain this volume entirely — usually, small portions of 200-300 mL are required. Therefore, this tank plays the role of a buffer — when the user drains the next portion of water, water from a bottle or a water mains is added to the tank; such an admixture does not particularly affect the temperature in the tank, however, for an additional guarantee, the heating system immediately turns on. Thus, if the consumption does not exceed the heating capacity, the temperature of the contents remains practically unchanged.
Cooling power
It is the power consumed by the device in water cooling mode. In other words, this is the power required for the operation of all elements of the cooling system — a compressor or a converter with a fan (depending on the type of cooling, see above).
This parameter is directly related to the cooling performance (see above): a high cooling rate inevitably requires appropriate power. However, with the same power, compressor systems are more performant than electronic ones. Only models with coolers of the same type can be compared in terms of power.
Also note that the cooling system does not consume this power constantly, but only when necessary. So, at room temperature of the water in the "cold" tank, it turns on at full capacity, and when the desired temperature is reached, it switches to its maintenance mode, which requires much less energy.
In cooling-only models, this figure describes the maximum power consumption of the entire device. And, if there are two modes (heating and cooling), the total maximum power consumption corresponds to the sum of the powers of both modes.