Electric heating convectors: choice, power calculation

Traditional for our country, water heating is complex and expensive at the installation stage. Therefore, many are looking for other options for heating rooms, crowbars, cottages and apartments. The first thing that comes to mind is electric heating convectors. Installation is super simple: put it on or hang it, plug it into a power outlet. All. You can warm up. The only limitation is whether the wiring can withstand such a load. The second is decent electricity bills, but they can be reduced by installing a two-tariff meter. 

What is convection and convector

Convection is the process of heat transfer due to the movement of heated air. A convector is a device that heats the air and promotes its movement. There are convectors in which heating occurs due to the circulation of the coolant, then they are part of the water heating. But we will talk about electric convectors, which convert electricity into heat, and air flows carry this heat around the room.

According to the installation method, convector electric heaters are wall-mounted, floor-mounted, floor-mounted (embedded below the floor level), plinth and universal (installed on the legs that come with the kit or hung on the wall).

It is impossible to say which form of electric heating convectors is better. All forms are developed taking into account thermodynamics (in any case, normal companies do this), so you base your choice only on your own preferences and on which design fits best into the design of the room. No one forbids putting electric convectors of various types in the same apartment, house or even in a room. The main thing is that the wiring can withstand.

The device of electric heating convectors

The device of the electric convector is simple:

• a housing in which there are openings for air intake and exhaust;
• a heating element;
• sensors and control and monitoring device.

The case is heat-resistant plastic. The shape can be flat or convex, rectangular or square. There are holes in the bottom of the case – cold air is sucked into them. There are also holes in the top of the case. Hot air comes out of them. The movement of air occurs without stopping, and the room warms up.

The heating element of an electric convector is what you need to pay attention to when choosing. The service life of the equipment and the air condition depend on the type of heater.

Types of heating elements for electric convectors

Heating elements in electric heating convectors are of three types:

• Needle. This is a dielectric tape in which needle loops made of an alloy of chromium and nickel are mounted. The surface of the heater is filled with a layer of protective varnish. The hinges stick out from both sides, heat up very quickly, cool down just as quickly, and this is a plus of such heaters – it is easy to maintain the set temperature. The second positive point is the low cost. Electric convectors with needle-type heaters are a third cheaper. disadvantages – it cannot be used at high humidity, the fragility of the needles leads to the fact that such a heating element quickly fails.
  

  

• TEN. Tubular electric heater. This is a hollow metal tube inside which a spiral is sealed. The distance between the spiral and the body is filled with heat-conducting backfill. Plates-fins are additionally soldered on heating elements for convectors to increase heat transfer. The disadvantages of this heater are relatively low efficiency, large inertia – due to losses during heat transfer from the coil to the body – it takes time to reach the operating mode. Another drawback: during operation, the heating element may crackle. The reason is the different temperature expansions of the materials used. Advantages – the spiral is reliably protected, the convector heater can be used in wet rooms. Also a positive point is a long service life.
  

  

• Monolithic heaters are the quietest, with minimal heat loss. The same thread made of nickel-chromium alloy is soldered in a cast body with fins. Heat loss during transfer from the thread to the body is minimal, the thermal expansion of all parts is the same.
  

  

Electric heating convectors with monolithic heaters are considered the best, but they are also the most expensive. With the use of heating elements – a little cheaper.

Types of thermostats and controls

Electric heating convectors can be controlled by a mechanical thermostat or electronics. The cheapest convector electric heaters have a thermostat, which, when the set temperature is reached, breaks the power supply circuit of the heating element. When cooling down, the contact appears again, the heater turns on. Devices of this type cannot maintain a constant temperature in the room – the thermostat is triggered by heating the contact plate, and not by air temperature. But they are simple and quite reliable.

Electronic control uses several sensors that monitor the state of the air in the room, the degree of heating of the device itself. The data is processed by a microprocessor, which corrects the operation of the heater. The desired mode is set from the control panel located on the body, and there are also models with a control panel. You can find programmable models that allow you to set the heating mode for a whole week – while no one is at home, set it to maintain about + 10 ° C or lower and save on bills, warm up the room to a comfortable temperature by the time people arrive. There are generally “smart” models that can be integrated into the “smart home” system and controlled from a computer.

Choosing an installation site

Rather, the question is not like this: which of the convectors is suitable for fulfilling your wishes. If you want to bring the appearance of the room closer to the standard, you can hang rectangular wall convectors under the windows. A little more attention is drawn to models that can be installed under the ceiling, but they are inaccessible to children and pets – they will not be able to burn themselves or “adjust” in their own way. The mounting method is the same here – on brackets fixed on the wall. Only the shape of the brackets is different.

If you want the heaters not to be visible, you will have to choose between skirting models and floor models. There is a big difference in installation: the skirting boards were simply installed and plugged into the network, and under the floor ones you will have to make special recesses in the floor – their top panel should be on the same level with the finished floor. In general, you can’t install them without a major overhaul.

Power calculation

If the convector is needed only as an additional source of heat – for a period of severe cold – it makes sense to take a couple of low-power devices – 1-1,5 kW each. They can be rearranged in those rooms where it is required to raise the temperature. If convector heating is the only source of heat, everything is much more serious.

If everything is done “wisely”, it is required to calculate the heat loss of a house or apartment and, based on the results of the calculation, select equipment. In fact, this is very rarely done. Much more often they consider the required heating power by area: for heating 10 square meters. m. area requires 12 kW of heat. But these are the norms for the average ceiling height – 2,50-2,70 m and average insulation. If the ceilings are higher (you need to heat the volume of air) or there is absolutely “no” insulation, the power is increased by 20-30%.

Manufacturers, characteristics and prices

Electric convector heaters are produced by several companies that produce other household appliances – Electrolux, AEG, Hyundai, Stiebel Eltron, Zanussi. In addition, there are many companies that specialize in just such a technique or produce two or three more groups of goods. Among them there are Russian manufacturers – Ballu, Termica, Ural-Mikma-Term, Alvin. There is also a whole group of European brands:

• Airele, Noirot and Atlantic (France),
• Extra, Royal Thermo, Scoole, Тimberk, WWQ (КНР),
• Frico (Sweden),
• NeoClima (Greece),
• Nobo (Norway)

and many more others. Electric heating in Europe is the norm, they rarely have water heating. Hence the number of companies involved in the production of such household appliances. But, as usual in recent years, most firms have moved production to China, so the assembly is mainly Chinese, although quality control should be at the level.

Electric heating convectors can be from 0,5 kW to 2,5-3 kW. They work mainly from a 220 V network, if necessary, you can find three-phase ones – from 380 V. With an increase in power, dimensions (mainly depth) and price increase. If we talk about prices on average, then for imported electric convectors the price is about $ 80-250, for Russian – $ 30-85.

Useful additional features

When choosing electric heating convectors, pay attention not only to technical parameters. There are additional features that increase comfort and safety:

• Overheat protection. An additional sensor is installed on the case, which turns off the power when the threshold value is reached. Usually it is +60°C.
• Shutdown when dropped. This function is relevant for models with a floor installation method. If you change the position (fall or strongly tilt), the power turns off. This feature prevents possible fires.
• Restart. When you turn it on again, the electric convector automatically sets the settings that were when it was turned off.
  

  

Overheating protection and drop-off shutdown are very useful features that increase the safety of the equipment. What else you can pay attention to is how quiet or loud the unit works. It’s not just about the heating element (it usually clicks). When activated, the mechanical thermostat also clicks. If you are choosing convection heaters for your bedroom, silent operation is very important.