Features
Additional functions provided in the design of the unit in addition to ventilation.
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Recuperator. A heat exchanger that prevents "blowing" heat from the room during the cold season. The principle of operation of the
heat exchanger is that it takes energy from the blown air and transfers it to the incoming one — thus, ventilation sends relatively cool air out and supplies preheated air into the room. The use of
a heat exchanger can significantly reduce heat loss and, accordingly, heating costs — the amount of heat returned in the most advanced heat exchangers can reach 97% (see "Heat exchanger efficiency"). At the same time, such systems are often passive and do not themselves consume energy (and where it is required, the consumption is still lower than the amount of saved heat). Naturally, this function is found only in full-size,
supply and exhaust units (see "Type of ventilation"). Note that external
recuperators are also produced, which can be supplemented with ventilation units that do not have this function; however, an integrated heat exchanger is often more convenient and efficient.
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Heater. The built-in heater intended for heating the air coming into the room. At the same time, in contrast to the heat exchanger described above, energy is used
...for heating from a third-party source — an electric heater or a water heat exchanger (see "Heater type"). This method of heating requires additional energy costs, and water circuits are also quite troublesome to connect. But it is much more efficient: if the air supplied from the heat exchanger into the room cannot be warmer than the air blown out, then this is not a problem for the heater. This function is mainly used to raise the temperature of the supply air supplied from the heat exchanger (built-in or separate) to the temperature of the extract air and thus avoid unnecessary heat losses.
— Cooler. A built-in system that reduces the temperature of the air supplied to the room. Simplified, this function can be called a "built-in air conditioner" — because air conditioners are usually used to cool the air in hot weather. In fact, in some cases, installing an air ventilation unit with a cooler can eliminate the need for separate air conditioners. On the other hand, such systems are quite complex and expensive, and therefore they are used rarely, mainly among centralized units(see "System").
— Humidifier. A system that increases the humidity of the air supplied to the room. The peculiarity of the human body is such that the feeling of a comfortable climate depends not on the absolute, but on the relative humidity of the surrounding air. Relative humidity, on the other hand, depends not only on the actual amount of water vapour in the air but also on temperature: physical laws are such that as the temperature rises, relative humidity drops, even though the amount of moisture in the air remains unchanged. In fact, this leads to the fact that during the cold season, the heated outside air begins to seem dry. To avoid this effect in climate technology, including air ventilation units, humidification systems may be provided. Note that such systems usually require either a connection to the water supply system or regular refilling of the water tank.
— Ionizer. A system that saturates the air entering the room with negatively charged ions. The effect of such ions on the climate is positive — the air feels fresher, ionization contributes to the sedimentation of contaminants on the floor and walls and provides a bactericidal effect. In addition, it is believed that ionized air is good for health, improves immunity and recovers from injuries and illnesses.CO₂ carbon dioxide sensor
A built-in sensor that determines the content of carbon dioxide in the room.
The CO₂ carbon dioxide sensor controls the operation of ventilation and performs two functions at once: it prevents a critical increase in the level of carbon dioxide in the air and at the same time provides energy savings. Recall that carbon dioxide is emitted by people when they breathe, and its high content in the air leads to a deterioration in well-being and even serious health problems. Thus, if the sensor detects an increased concentration of CO2, it increases the intensity of ventilation, providing an additional supply of fresh air. When the concentration of carbon dioxide drops, the intensity of work decreases (up to a complete shutdown if there are no people in the room and the CO2 content does not change); this avoids unnecessary electricity consumption.
Heater type
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Electric heater. Heaters are called devices designed to increase the temperature of the air entering the room; such devices are installed behind the heat exchanger (when viewed from the outside). And
the electric principle of heating is the most popular among the heaters. It is due to the simplicity and ease of installation: all the necessary equipment is already in the ventilation unit, you just need to supply power. The disadvantage of this option is considered to be a rather high power consumption; in addition, most powerful electric heaters require a 400 V power supply, and such a connection is far from being available everywhere — additional wiring may be required.
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Water heater. Heater powered by a water heat exchanger. See above for more details on heaters in general; the heat exchanger is connected to a heating system powered by a boiler or other heater. The main advantage of this option is the fact that the heater itself does not consume electricity and is often cheaper to operate (especially if the boiler runs on gas or solid fuel), even though its power can be very impressive. In addition, by directing part of the heating power to heating the air, it is possible to achieve a more efficient use of the boiler capacity. At the same time, connecting a water heater is a rather complicated matter, which is why such devices are used somewhat less often than electric ones.
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— Water and electric heater. The presence in the design of both water and electric heaters. See above for details of each variety; their combination in one unit increases the overall efficiency, allows you to adjust the heating power and choose the type of heater depending on the situation. For example, in winter, you can mainly use a water heater, including an electric one only when the outside air temperature drops sharply when the water heat exchanger is no longer enough. And in case of an unexpected cold snap in the warm season, when there is no need to start the boiler, you can turn on only the electric heater and provide heat in the room. On the other hand, such versatility significantly affects the price, but in fact, it is rarely required. Therefore, this option has not received much distribution.
— Electric preheater. Electric pre-heater installed outside of the heat exchanger — in such a way that the outside air first enters the pre-heater, then the heat exchanger (unlike heaters, which heat the air after the heat exchanger). In addition to the actual heating, such a device is also designed to protect the heat exchanger from freezing during the cold season (or to defrost an already frozen heat exchanger).
— Electric heater and preheater. A design that combines two types of electric heaters at once — a heater and a preheater. About the features of both, see below, but here we note that such a combination provides high heating efficiency. However, it is not cheap.Heater power
The power of the main heater used in the air ventilation unit. For models with two heaters (see "heater type"), this item indicates the power of the main heating element; at the same time, in units with water-electric heating, the water heat exchanger is considered the main one, in units with a preheater and afterheater, the afterheater.
Power determines primarily the amount of heat produced by the heater. This parameter is selected by the designers for the performance of the installation so that the power is enough for the volume of air passing through the unit. Thus power is more of a reference parameter than practically significant: most likely, it will be enough one way or another for the effective use of the installation. We note only some of the nuances associated with particular types of heaters. So, in water heaters, the actual power depends on the temperature of the supplied coolant; in the characteristics, indicators are usually given for a temperature of 95 °C, at a lower value and power, respectively, will be lower. With electric heating, the power consumption of the heater and, accordingly, the requirements for its connection directly depend on the power.
