Heating area
A very conditional parameter that slightly characterizes the purpose based on the size of the room. And depending on the height of the ceilings, layout, building design and equipment, actual values may differ significantly. However, this item represents the maximum recommended area of the room that the boiler can effectively heat. However, it is worth considering that different buildings have different thermal insulation properties and modern buildings are much “warmer” than 30-year-old and especially 50-year-old houses. Accordingly, this item is more of a reference nature and does not allow us to fully assess the actual heated area. There is a formula by which you can derive the maximum heating area, knowing the useful power of the boiler and the climatic conditions in which it will be used; For more information on this, see "Useful Power". In our case, the heating area is calculated using the formula “boiler power multiplied by 8”, which is approximately equivalent to use in houses that are several decades old.
Rated current
The current consumed by the electric boiler (see "Power source") during normal operation.
This parameter directly depends on the power. It is required primarily for organizing the connection: wiring and automation must safely deal with the current consumed by the unit.
"Summer" mode
It is an operating mode designed for the warm season. In this mode, it works only to provide domestic hot water, and the heating is turned off. If the boiler is equipped with an outside temperature sensor, this sensor is also switched off in
summer mode so that the heating does not turn on at night when the outside temperature drops.
Heated floor mode
The boiler has a special
mode for underfloor heating systems.
Underfloor heating differs from conventional heating systems primarily by a
lower coolant temperature — otherwise the floor could be too hot for comfortable use (plus, high temperatures are also undesirable for flooring and furniture installed on it). In addition, boilers with this function are distinguished by increased pump power. In order to ensure efficient circulation of the coolant through branched heating circuits that have rather high resistance.
Efficiency
The efficiency of the boiler.
For electric models (see "Energy source"), this parameter is calculated as the ratio of net power to consumed; in such models, indicators of 98 – 99% are not uncommon. For other boilers, the efficiency is the ratio of the amount of heat directly transferred to the water to the total heat amount released during combustion. In such devices, the efficiency is lower than in electric ones; for them, a parameter of more than 90% is considered good. An exception is gas condensing boilers (see the relevant paragraph), where the efficiency can even be higher than 100%. There is no violation of the laws of physics here. It is a kind of advertising trick: when calculating the efficiency, an inaccurate method is used that does not take into account the energy spent on the formation of water vapour. Nevertheless, formally everything is correct: the boiler gives out more thermal energy to the water than is released during the combustion of fuel since condensation energy is added to the combustion energy.
