Comparison Hotpoint-Ariston VLS EVO 80 EU vs Atlantic Vertigo Steatite 80

The volume of the tank installed in the storage water heater (see "Type"). It is one of the key parameters for such devices. On the one hand, a large tank allows you to keep a large supply of water and reduces the risk that it will run out at the most inopportune moment; this is especially important when water consumption is high, such as in a large family. On the other hand, a volumetric tank correspondingly increases the size, weight and cost of the entire device, requires reliable fastenings (when installed on a wall), and more energy is spent on heating and maintaining the temperature of the water in it. Accordingly, when choosing, it is worth not chasing the maximum volume but proceeding from the actual water consumption and this point of view determining the optimal capacity of the tank.

Some special tables and formulas allow you to calculate the optimal volume of the tank depending on the format of use (washbasin, shower, kitchen sink ...), the temperature of the water used and other parameters. These data can be found in special sources. Here we note that the smallest storage water heaters can hold only 5 litres; such devices are designed for washing, washing dishes for 1 – 2 people and other tasks that do not require a lot of water. The average value is considered to be a volume of 80 – 100 litres, such a tank is quite enough for an apartment in which 3 – 4 people live. In the largest models, the volume is already calculated in cubic metres; such water he...aters are designed, for example, for hotel buildings, showers in sports complexes and swimming pools, and other similar places where a lot of hot water is required.

The presence of 2 water tanks in the storage water heater; usually, the total volume is divided equally between these tanks.

This design is noticeably more complex and expensive than the traditional 1-tank arrangement but offers several advantages. Firstly, the tanks can be heated in turn, which significantly speeds up the process. After all, for hot water to be used, it is enough to warm up only half of the total volume to the operating temperature. Secondly, with this format of work, power consumption and the load on the power grid are reduced. And if at a certain moment, the user does not need a lot of water, then the energy consumption turns out to be small (again, because the entire volume does not need to be heated). Thirdly, compared to traditional models of the same volume, such boilers are thinner, which can simplify installation (the price for this advantage is an increase in width, but this moment is not so often critical). Fourth, this arrangement improves thermal insulation and reduces heat loss.

The shape of the water heater.

The traditional options are cylindrical and rectangular, but nowadays there are more specific options — flat cases, slim cylindrical devices. Here are the features of each of these options:

— Cylindrical. This form is traditional for storage water heaters. It is because with the same total volume, less material is needed for a cylindrical tank than for a rectangular one; and in production, such tanks are simple and cheap, which allows them to be used in water heaters of any price category. The disadvantages of this form include, first of all, some bulkiness in comparison with other options.

— Rectangular. The case is rectangular in shape, with pronounced front and side faces; the corners can be both sharply defined and rounded. It is the traditional form for instant water heaters, primarily gas, but it can be found in a fairly large number of storage models. Accordingly, the features of a rectangular case will be different — depending on the type of heater. So, in instant water heaters, the “rectangle” is simply one of the most convenient options in terms of the overall layout. But in storage water heaters, this shape differs from the flat one (see below) only with a slightly greater thickness and, in some cases, pronounced angles.

— Flat. A variant found mainly in s...torage electric heaters. Such devices look as if the classic cylindrical body was flattened at the back and front, reducing its thickness by increasing the width (and sometimes height). Thus, such a boiler does not protrude as much in front of the wall as a cylindrical one; in some cases, this point may be fundamental — for example, when installed in a bathroom, where a cylindrical device would hang over the toilet bowl, creating discomfort.

— Slim. A variety of cylindrical cases are characterized by a reduced diameter. In other words, boilers from this category are also round, but with the same volume, they have a noticeably smaller width and thickness than traditional cylindrical ones. In cramped conditions, this can be very useful. However, it must be borne in mind that the price for reducing the diameter is an increase in height.

This parameter characterizes the efficiency of electricity consumption by the water heater. Classes are indicated by latin letters from A to G (A, B, C, D), where A is the most energy efficient device.

Electrical power consumed by the heater during operation.

This parameter is of key importance for electric models (see "Energy source"). In them, the power consumption corresponds to the power of the heating element and, accordingly, the heat output of the entire device. The overall efficiency and flow rate of the water heater directly depend on the useful power. Accordingly, high-flow rate models inevitably have high consumption. At the same time, we note that the heating power is selected by the designers in such a way as to guarantee the necessary flow rate and water temperature. So when choosing a device according to flow rate, you need to look primarily at flow rate and temperature. Power must be taken into account when connecting: for example, if a 220 V model (see "Power source") consumes more than 3.5 kW, it, as a rule, cannot be plugged into a regular outlet — connection is required according to special rules. And the most productive and high-powered models — 10 kW or more — are connected only to three-phase mains.

The power consumption has a similar value for combined boilers — adjusted for the fact that in them the electric heater is an additional source of heat. For gas and indirect models, this parameter describes the power consumption of control circuits and other auxiliary structural elements; this power consumption is usually very small — on the order of several tens of watts, less often up to 1.5 kW.

The highest water temperature provided by the device. The standard temperature of hot water in the water supply is 60 °C, and this value is actually the minimum for modern water heaters: models with more modest rates (usually from 40 °C) are extremely rare. But higher values can be found much more often: for example, water heaters of 75 °C and 80 °C are very popular, and in the most powerful models in this regard, the temperature can reach 95 °C and even higher.

On the one hand, strong heating requires appropriate power (which is especially noticeable in the case of instant electric heaters). On the other hand, the higher the temperature of hot water, the less it is needed for a comfortable outlet temperature, after mixing with cold water; this reduces the consumption of heated water, which is especially important for storage boilers. In addition, many models have thermostats (see "Features").

Also, note that heating to operating values may involve different ΔT (degree of temperature change) — depending on the initial temperature of the cold water. The actual performance of the heater directly depends on ΔT; this moment is described in more detail below, in the paragraphs devoted to performance at different ΔT.

Time to heat the storage tank (see "Type"), filled with cold water, to operating temperature.

It is worth remembering that this characteristic is not 100% accurate. Manufacturers usually indicate the heating time for certain conditions: a filled tank, maximum heating intensity, and temperature rise (∆T) by a certain number of degrees. In practice, the heating time may differ, both one way and the other. For example, if the heating time for the device is 20 minutes at ∆T = 50 °C, then when the water is heated from 15 °C to 60 °C, the time will be shorter (∆T = 45 °C). Nevertheless, this indicator allows us to evaluate the overall flow rate of the boiler, and with equal ∆T and volumes, different models can be compared in terms of heating time.

— Open coil. The open coil is made from a high-resistance electrical wire enclosed in a thin insulating sheath. The main advantages of such an element are the heating rate, high efficiency and precise temperature control; in addition, scale is almost not formed on the spiral. And of the shortcomings — a low service life.

— Wet heating element. Wet heater is a metal tube with a heating thread laid in the centre; the space between the tube and the thread is filled with an insulating material with good thermal conductivity. Heating elements heat up more slowly than open coils, have lower efficiency and are prone to the formation of scale on them; on the other hand, their service life is much longer, and in instant heaters, heating elements are not so sensitive to air pockets.

— Dry heating element. A kind of heating element with an improved design: the heater tube is enclosed in an additional shell (most often made of metal with an enamel coating on the outside) and does not come into contact with water, hence the name. Thanks to this, the likelihood of scale formation is reduced, which is especially important when working with hard water. Also, the replacement of such elements is significantly easier than conventional ones. Among their shortcomings can be called a rather high cost.

— Infrared heating element. Tu...bular electric heater of a special design: in the form of a transparent glass tube, in which the incandescent spiral is enclosed. The principle of operation of such an element is somewhat different from a conventional heating element: a significant part of the heating is provided by infrared radiation, which heats not so much the water as the walls of the tank — and heat is already transferred from them to the water. Thus, the water is heated not only at the point of contact with the heating element but also at the point of contact with the walls — which means that the heating is faster and more uniform. Also, note that the IR heater itself is usually "dry"; see above for the advantages of this design. The main disadvantages of such heaters are high cost and relatively short service life.

— Heat exchanger. It is used in gas and indirect heaters (see Water heater type). It is a metal structure heated by burning gas (in gas heaters) or passing inside a heated coolant (in indirect heaters). Usually has a ribbed shape. It is done to ensure the maximum area of contact with the heated water with relatively small dimensions — the larger this area, the more heat is transferred to the water per unit of time and the more efficient the heater is.

Among the functions of the water heater there are thermostat, water flow regulator, Smart (auto mode), programmer, display and control via the Internet. More about each of them

— Thermostat. A device that allows you to control the temperature of the water at the outlet of the heater. In storage models (see "Type"), the thermostat sets the maximum temperature for heating water in the tank; in instant devices, this function is carried out by changing the intensity of heating.

— Automatic water flow regulator. It is used in instant water heaters. Since the water in such devices heats up in the process of its movement through the heater, the higher the speed of water movement (the greater the pressure), the lower the heating temperature, and if the pressure is too high, the power of the device may simply not be enough for effective heating. The use of an automatic water flow regulator avoids this — this system regulates the speed of water movement through the heater, limiting it if necessary.

— Smart (auto mode). A special “smart” mode in which the boiler is controlled (primarily the intensity of heating) automatically. Specific features of this mode may vary depending on the model. However, the following format of operation is most common: during...the first week of use, the device remembers at what time of the day the hot water was used, and then the heater’s operating mode adjusts to this data. Thus, the water heater provides the user with hot water at the right time and, at the same time, does not waste energy on heating during hours when heating is not needed.

— Programmer. The presence of a programmable thermostat — a device that allows not only to maintain the temperature but also to programme the operation of the device for a certain period. The simplest programmers work like a timer, turning on at the right time (vacation or holiday mode, when the device is not active for several days, and when the family returns to the house, it will turn on and heat the water). More advanced ones allow you to set the mode of operation for individual days. Either way, this feature provides added convenience and eliminates the need to constantly adjust the operation of the device manually. On the other hand, the presence of a programmer affects the cost.

— Display. Usually, a simple LCD screen with a few characters is used as a display. However, even such equipment significantly increases the convenience and information content of management. Various service data can be shown on the display — from the temperature of the water in the tank to messages about malfunctions and failures. This feature slightly increases the cost of the device, but compared to the total cost of the heater, this moment is usually insignificant.

— Control via the Internet. The specific nuances of such control may vary: for example, some models use a special application installed on a smartphone or tablet, while others can work through a regular browser from any computer. However, this function allows you to control the heater from almost anywhere in the world — provided that there is access to the Internet. In addition, with this control, the user can also monitor the status of the device and receive various notifications (on and off, about the temperature of the water in the tank, about various problems, etc.).