- Device, types and principle of operation of fan heaters
- Comparative characteristics of three models of fan heaters
- Fan heater selection criteria
Today we will talk about household fan heaters. Consider their types, device and installation methods. Let’s compare the characteristics of heating elements: incandescent spiral, sintered and glass-ceramic plates, heating elements. Let’s make a comparative review of fan heaters of three brands of equal power.
The popularity of household fan heaters is primarily due to their relative cheapness and availability – starting in the fall, they can be bought at any hardware store. However, models from this group of devices for heating premises differ not only in brand, appearance and color, their performance and service life depend on the hidden characteristics. We will study the device of different types of fan heaters so as not to make an annoying mistake when choosing them.
Device, types and principle of operation of fan heaters
This type of heating device works on the principle of heat ventilation – the flow of cold air created by the fan enters the heating element, its temperature rises and the already heated air flow enters the room. Stationary models of fan heaters are equipped with a rotary device that allows you to more efficiently distribute the heated air around the room. The main advantages of a fan heater are the ability to quickly warm up the air in the room to the desired temperature, with a narrowly directed flow – to create comfortable conditions in a separate area of the room. In the warm season, fan heaters can be used as a regular fan, i.e. without heating the air.
Any fan heater, regardless of power, size and installation method, consists of the following main parts – a casing, a fan and a heating element. The casing of fan heaters is made of a combination of impact-resistant plastic and metal. We will consider the characteristics of the types of heating elements and fans that impart basic performance to the device in more detail. Any fan heater is equipped with a heating element of one of three types – tubular (TEN), spiral or ceramic.
A heating element in the form of a spiral is usually made of nichrome – a wire made of this alloy is wound on a non-combustible base, often ceramic. A nichrome heating element exists both in the open form, i.e., the wire coils in it are not protected by anything from the outside, and in a closed form, being placed in a glass flask (without filling with an intermediate heat carrier). The main advantage of a fan heater with a nichrome heating element is its low cost, however, the combination of a high heating temperature (about 1000 ° C) and lack of protection or insufficient protection of the coil surface when the heater overturns can cause a fire. A serious drawback is the odor caused by the combustion of dust particles deposited on the incandescent heating element, the surface area of which is too small to quickly heat the air flow at a lower heating temperature. It should be noted that the widespread information about the “combustion of oxygen” during the operation of a nichrome heating element is false, since oxygen consumption occurs only in the presence of an open flame, and the heating of the nichrome spiral is caused by resistance to the electric current passing through it.
The heating element made of glass ceramics is more modern than its analogue made of nichrome wire – its heating temperature usually does not exceed 150 ° C, which means that it is safer. There are several ways to manufacture a ceramic heating element, the most popular is the method of pressing a powder mixture with its subsequent annealing in a high-temperature furnace. The ceramic plate of the heating element contains many tiny holes through which the air blown by the fan passes and heats up. It should be noted that the area of this plate is much larger than that of a spiral heating element or a heating element, due to which the air, when passing through it, heats up to a higher temperature in a short time. With one more positive feature – rapid heating of the plate (it takes only a few seconds, that is, more quickly than heating the spiral element and many times faster than the heating element heating time), fan heaters with a ceramic heating element cost three times more than those equipped with a spiral analogs.
Ceramic heating element
In addition to heating elements made of glass ceramics, there are externally similar sintered metal elements for heating. By their design, they are something in between a spiral and a ceramic element – a nichrome wire is placed inside a ceramic case. The characteristics of sintered and spiral heating elements are practically identical, with the exception of the lower fire hazard of sintered elements.
A heating element in the form of a heating element is a quartz or metal tube containing a heating element made of graphite or wire, with filling the free space around it with manganese oxide and quartz sand. In the design of fan heaters, a metal heating element with a quartz filler and a wire heating element made of nichrome is most often used – the filler distributes the generated heat over the entire area of the heating element, which allows the temperature of the nichrome filament to be halved (up to 500 ° C). Thanks to this, a fan heater equipped with a heating element can work twice as long as a device with a spiral heating element, but its cost will increase significantly. Since the use of heating elements can significantly increase the power of the fan heater, such devices are used mainly for industrial needs and are called heat guns.
Fan heaters are equipped with two types of fans, depending on the size, made of metal or plastic:
- Axial, equipped with blades familiar to us, usually small in size and installed only on portable models of devices. The disadvantage of axial fans is constant noise during operation.
- Tangential, outwardly similar to an oblong cone, along the length of which there are a dozen two or three blades parallel to each other. Tangential fans are less noisy and generate more air flow than axial fans, however, they are longer and therefore are installed only in column-shaped wall and floor appliances.
At the place of installation, fan heaters are divided into portable (tabletop) and stationary, the latter, in turn, are divided into floor and wall models.
Desktop fan heaters of small size and medium power (400-2000 W), which makes them easy to transport, store and install, are equipped only with axial fans, therefore they work with noticeable noise.
Column-shaped floor-standing units are usually equipped with a low-noise tangential fan mounted vertically, which explains the design of the column-shaped case. Their power ranges from 1800-2500 watts, they are more powerful than portable devices, most floor models are equipped with an automatic rotation device.
Dimplex DXSTG25 Studio G
Externally, wall-mounted fan heaters are similar to a split-system unit installed indoors. Equipped with a tangential fan and having a power of 2000 to 2500 W, such devices are used both for heating rooms and for cutting off cold air – as an air curtain at the entrances to cafes, shops and office buildings.
Comparative characteristics of three models of fan heaters
The review will be conducted with the participation of portable (desktop) fan heaters of the brands Polaris, Scarlett and Zanussi with a power of 2000 W.
Model Polaris PFH 5020 Scarlett SC – FH53002 Zanussi ZFH / С-405 Power supply and power Voltage, V 220 220 220 Power consumption, W 2000 2000 2000 Recommended heating area, m2 20 20 20 Heating power, W 1000/2000 1000/2000 1000/2000 Functions Number of working modes 3 3 3 Ventilation without heating there is there is there is Control Thermostat type mechanical mechanical mechanical overheat protection there is there is there is Heating mode control mechanical mechanical mechanical General characteristics Body material plastic plastic plastic Colour black / orange Gray GREY-black Fan type axial axial axial Heating element type spiral spiral ceramic type of instalation desktop desktop desktop, floor Size WxHxD, cm 19.8×26.3×14 22x27x13 18.6×25.2×17.5 Weight, kg 1 0.86 0.98 Handle for moving there is there is not Brand owner Texton Corporation LLC, USA Arima Holding Corp., Russia AB Electrolux, Sweden Manufacturer country China China China Guarantee 1 year 2 years 2 years Average cost, rub. 990 990 2000
Polaris PFH 5020
Scarlett SC – FH53002
Zanussi ZFH / С-405
All three brands of fan heaters described have the same ability to heat a room. The companies owning the described trademarks of devices have created a fairly extensive network of service centers in the CIS, which serves as a positive criterion for choosing.
Fan heater selection criteria
Power is selected at 1000 W per 10 m2 the area of a room with a ceiling not higher than 2.7 m. At the same time, it is more profitable to purchase a device with a power 30-50% higher than necessary – in case of especially cold days.
The best choice would be a device with a glass-ceramic heating element, which during operation will not burn dust drawn into the heater, accompanying heating with a characteristic odor. It should be borne in mind that many manufacturers somewhat distort the technical information, claiming a “ceramic element”, which is actually a “cermet”, that is, almost identical to the spiral element.
The more controlled heating modes of the fan heater (their maximum number is 3) – the better, since this will allow you to get a more comfortable temperature level in the room without constant adjustment of the thermostat in the device.
The ideal characteristics of the fan heater are a ceramic element, 3 heating modes, flexible settings for the fan rotation rate, the presence of a rotary (rotating) base, a low-noise fan (preferably tangential), a thermostat, shutdown sensors when overheating and when the device falls (for desktop and floor models).
The rules for handling the fan heater during operation are simple: do not drag it by the cord; do not drop, especially when the device is on; do not use in a damp room; under no circumstances pour any liquid onto the heater; the minimum permissible distance from the device to objects on either side is 50 cm.We highlight one important requirement separately – it is strictly forbidden to cover the fan heater case with anything, since it will overheat and may ignite!