Comparison Hotpoint-Ariston PRO1 R 80 V 1.5 K PL DRY vs Hotpoint-Ariston SG1 80 V

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.

Heat losses arising in the storage water heater due to imperfect thermal insulation of the tank.

No insulating material, even the highest quality, can completely prevent heat from escaping to the outside. This paragraph just indicates the amount of heat that “leaks” through the thermal insulation of the boiler per day; to maintain the temperature, this leakage must be compensated by additional heating, even if no water is consumed. So from a practical point of view, heat loss is the amount of energy that the heater spends solely on maintaining the temperature of the water inside. Accordingly, the lower this indicator, the more effective the thermal insulation and the more economical the device is in terms of energy consumption. On the other hand, a decrease in heat loss inevitably affects at least the cost, and often also the size and weight of the heater.

Note that this parameter is indicated for standard conditions: a filled tank, heated to operating temperature, zero water flow and a certain outdoor temperature (usually about 20 °C). Under other conditions, the actual level of heat loss may differ from the claimed one in one direction or another. Nevertheless, according to this characteristic, it is quite possible to compare different models directly: lower heat losses claimed by the manufacturer will mean more economical energy consumption.

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.

Magnesium anode is used in storage heaters (see type). It is an additional means of protecting the tank and heating elements from corrosion. Due to its special electrochemical properties, magnesium significantly slows down the oxidation of other metal parts that come into contact with water. Note that the magnesium anode has a limited service life. It needs to be changed every 5-7 years.

— 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.... Tubular 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.

The warranty period declared by the manufacturer for the storage water heater tank (see “Type”).

This parameter is important for the reasons of maintenance terms. The tank is the most complex element: other parts of the water heater are relatively easy to repair and change, and if there is a problem with the tank, it is often easier to replace the entire boiler. In the most advanced models, the warranty on the tank can be 10 years or more.

The weight of the device, excluding the water collected (passing) into it.