Heating area
The area that the device can effectively heat. This parameter directly depends on the maximum power (see above). It should be noted that the actual efficiency of the heater in most cases does not depend on the area but on the volume of the room. Thus, the heating area can only be specified for a certain ceiling height. In most cases, manufacturers mean 2.5 m — this is the standard ceiling height in city apartments. If the ceilings are much higher, the heating area must be recalculated using special formulas. In general, it is worth orienting that 1 kW is enough for 10 m². However, manufacturers may slightly overestimate the heating area data.
Safety system
— Overheat protection. The system of automatic shutdown of the heater when the critical temperature of the heating element is reached (which can happen, for example, if the fan heater motor fails). Ensures the fire safety of the device.
— Frost protection. This function does not protect the heater itself, but the room in which it is installed. When the frost protection is on, the heater automatically maintains the room temperature at 5 °C, turning on and off at the right time. This allows you to protect the walls of the room (for example, a country house) from freezing without the extra cost of electricity or gas.
— Waterproof. The presence of a body protected from water splashes (most often sealed). Such heaters can be used in rooms with high humidity — for example, bathrooms — without the risk of short circuits or electric shock. However, even in such models, it is imperative to clarify the specific degree of water protection and restrictions on use before use; these data can be found in the instructions or other official documents of the manufacturer.
— Child lock. The control lock function prevents playful children or animals from changing the settings. Relevant for advanced devices with extensive management capabilities.
— Tip-over protection. A system that turns off the heater when it tips over to avoid fire or damage to the floor. This feature is especially relevant if there are small children in the house.
—...Motion sensor. The presence of an appropriate sensor allows the device to focus on the presence of people and, by this, warm up the room. So, the absence of any movement in the "field of view" of the heater puts it into sleep mode. And the detection of movement (be it a dog or a person) reactivates it.
— Open window sensor. A special sensor allows the device to automatically recognize when a window is opened for ventilation. In the process of airing the premises, the heater either turns off completely or switches to the most economical operation mode. This function allows you to save energy because, in the process of ventilation, the room heat will still evaporate into the street. Usually, the heating stop time is up to 30 minutes — in some models, the exact ventilation time can be adjusted by the user. The very fact of ventilation is most often fixed by the electronics. To do this, automation can use either traditional magnetic contact sensors or draft sensors (cold air inflow).
