Volume
The nominal capacity of a kettle refers to the maximum amount of water that can be safely poured into it, and it is typically indicated by the water level indicator. In the case of brewing sets (see "Type"), the nominal capacity refers to the main kettle, while the capacity of the teapot is listed separately (see below).
The capacity of the electric kettle directly affects the amount of water that can be heated at once. A larger capacity allows for heating more water, but this also means the kettle will be larger and heavier. Additionally, heating a larger volume of water requires either more power or a longer time. Therefore, it is important to consider one's actual needs when choosing a kettle based on its capacity. For example,
mini-kettles for travelling (or for one person) have a volume of up to 1 liter. For home use in a family of 2 – 3 people, a 1,5 – 2 liter model is enough. Devices for
2 – 3 liters are already well suited for a small office or a similar situation. The most spacious electric kettles are designed to hold 10 liters or more, and are typically used in public places such as canteens and cafes for dispensing hot water.
Coating of the heating element
The outer covering of the heater is a significant factor in determining the characteristics of the kettle because it is in direct contact with the heated water. Therefore, the material used for this coating is an essential consideration in the kettle's properties.
— Stainless steel. "Stainless steel" is the most commonly used coating for kettles as it is affordable and provides good resistance to scale buildup. However, compared to more advanced materials, it may not offer the highest level of scale resistance.
— Aluminium. Another common material, slightly more expensive and resistant to scale than stainless steel, but in general not having significant differences.
— Ceramic. Ceramic coating is known for its exceptional resistance to both scale and corrosion. Although it cannot provide a complete guarantee against scale buildup, it does tend to form plaque at a much slower rate than on surfaces made of steel or aluminium. Additionally, many of these heaters can be cleaned with more aggressive descaling products that would not be suitable for metal coatings. However, due to their high cost, ceramic coatings are typically only used in premium kettles.
— Silver. Silver is another premium material that has good resistance to both scale and corrosion. In addition, it also possesses some antibacterial properties, making it a suitable choice for those who use the kettle to store cooled boiled water. However, the cost of silver pla...ting is quite high.
Body shape
The general shape of the body of the electric kettle.
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Conical. The most popular option: a body is wide at the base and tapering upwards. This form contributes to stability: the centre of gravity is maximally displaced downwards. However washing such a kettle from the inside may not be very convenient due to the relatively small size of the opening in the upper part.
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Cylindrical. The cylindrical shape provides more or less the same width of the body at the base and at the top. With the same height and base diameter, such kettles hold slightly more water than conical ones; in addition, such a device is easier to clean due to the wide opening for the lid.
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Inclined. The body which is inclined forward; the width of such a body is usually more or less the same over the entire height. Such kettles have an unusual, eye-catching appearance; in addition, it is easier to pour water from them — the device must be inclined at a smaller angle than with a cylindrical and even with a conical body. However, this option does not provide fundamental advantages over the same cylindrical shape, but it is more expensive, and therefore is not common.
