Selection criteria for convectors – overview

Recommendation points

• Convector design and operation
• Comparative characteristics of three convector models
• How to choose a convector
• Finally – installation and operation

In this article: the principle of operation and the device of the convector; types of heating elements and their characteristics; air thermostat is a mandatory heater control element; floor and baseboard convectors; comparative review of heaters of three different brands with the definition of the best model; convector selection criteria; correct installation and operation of the device.

Quiet, flat and compactly located on the wall – this type of heater invariably attracts the eye of homeowners who are concerned about the problem of additional heating of their home. The convectors displayed on store shelves are full of logos of famous brands, their manufacturers vying with each other promise long warranty periods, seasonal discounts are in effect – it is very, very easy to get confused, succumbing to the persuasion of sellers and as a result a device that is not quite suitable in terms of characteristics. The choice should be deliberate, and the heater itself should be effective and convenient for households. And in this case, an overview of convectors, their characteristics, device and selection rules will be very useful.

Convector design and operation

The design of the convector is very simple – a flat body, inside which there is an electric heating element and a thermostat, the regulator of which is brought out to the external panel. The convector body is made of 0.8 mm thick metal sheet, painted with epoxy-polyester or powder paint. The electric heating element can be one of three types: tape (needle), tubular or monolithic.

The tape-needle heating element is a narrow dielectric plate pierced on both sides by rows of protruding loops of chromium-nickel wire. In modern models of electric convectors, tape heating elements are rarely used – with a low cost price, almost complete absence of thermal inertia (heating and cooling of a heating element occurs in a few seconds) and a high heating temperature, their wire loops are too fragile. In addition, the tape heat element is not able to quickly heat the air, because the tape heating element does not have its own ribbing – it heats the convector body, due to the heating of which air convection occurs.

Tubular heating elements (heating elements), along the length of which are installed many aluminum fins, have retained their popularity for several decades. The efficiency of heat transfer from the heating element to the air is directly related to the number and location of fins. Positive characteristics of heating elements: lower temperature of the tube surface compared to the heating temperature of the nichrome filament located inside; longer service life, compared to the tape element; admissibility of installation in wet rooms (IP24). Their disadvantages: the temperature expansion of the steel tube of the heating element and the aluminum fins is different, therefore, crackling is heard during operation; rib plates do not fit tightly to the surface of the heating element steel tube and during operation this gap will only increase, increasing the heat loss of the device.

Monolithic heating elements are arranged differently than classical tubular ones – a nichrome thread with a dielectric filling is placed in a cast aluminum case, and the ribbing is its integral part. The advantage of a one-piece body with ribbing is that there is no difference in thermal expansion, which is present in the operation of heating elements with a steel tube and plate fins made of aluminum. The operation of solid heating elements is noiseless, intermediate heat losses are minimal, and the relatively low heating temperature of the finning plates allows to reduce the heating temperature of the convector body. Modern models of monolithic heating elements have rough (pebbled) surfaces, which is achieved by introducing a special additive into the aluminum alloy – roughness increases the efficiency of heat transfer, contributing to radiation heat transfer between the heating elements plates.

Modern convectors are equipped with a mechanical or electronic (programmable) thermostat and an overheating sensor without fail. The setting accuracy of the electronic thermostat is 0.1 ° C, the mechanical one is 1 ° C – electronic temperature control allows you to set and maintain the most comfortable temperature in the room with less energy consumption (its savings will be about 3%). The temperature range allowed in the thermostat setting is from 5 to 30 ° С.

The principle of operation of convectors is based on different densities of cold and warm air – denser cold air is collected in the room near the floor, warm air tends to the ceiling. The cavity of the flat body is equipped with two lattice slots located in its lower and upper parts – cold air enters the device, heats up on contact with a heating element located in the lower part of the body of any convector, becomes less dense and rises to the ceiling.

The hollow body of the convector acts as a kind of wind tunnel, in which the air draft is caused by its heating. The process of entering cold air, heating it and lifting it up, entering a new portion of cold air, etc. (convection) – lasts during the entire operating time of the convector. By the way, the slots at the top and bottom of the device are not parallel to each other – the upper one is located at an angle to the floor plane so that the heated air rises to the ceiling not in a straight line, but in a parabola, which makes it possible to increase air heat exchange. On average, heating the air in the room to the optimal temperature using a convector will take about 20 minutes, provided it has sufficient power and the outside temperature is not too low (not lower than -5 ° C).

The produced convectors are divided into two groups – floor (wall) and skirting, the height of the models of the first group is about 450 mm, the second – no more than 200 mm. At a low height, the length of skirting electric convectors can reach 2,500 mm, these devices can be conveniently installed under window openings, especially low ones. The low height with a considerable length allows the baseboard convectors to warm up well the lower layer of the air atmosphere in the room, however, their considerable length creates difficulties when choosing a place for their installation.

Comparative characteristics of three convector models

For an overview of the characteristics, convectors of popular brands “Noirot”, “Ballu” and “Nobo” with the same power of 1500 W were selected.

specifications	Noirot Spot E-3 1500	Ballu Plaza BEP / E-1500	Nobo C4E15
power supply and power consumption
voltage, V	220-230	220-240	220-230
frequency Hz	50	50	50
maximum power, W	1500	1500	1500
operating modes, power consumption
number of operating modes	1 (*)	2	1
first mode, W	–	750	–
second mode, W	–	1500	–
control
room thermostat	electronic	electronic	electronic
overheat protection	there is	there is	there is
rollover shutdown	not	there is	not
control of heating modes	mechanical	mechanical	mechanical
light indication when the mode is turned on	there is	there is	there is
led display	not	there is	not
General characteristics
type of shell	vertical monoblock	vertical monoblock	vertical monoblock
body material	metal	tempered glass and metal	metal
primary colors	White gray	the black	White gray
heating element type	solid aluminum	solid aluminum	sintered heating element with ribbing
type of instalation	wall / floor	wall / floor	wall
moisture protection	IP 24	IP 24	IP 24
electrical protection class of the case	II	II	II
wall mounting kit	there is	there is	there is
removable legs (wheels) included	no (additional option)	there is	no (not supplied)
for space heating, m2	15-20	15-20	15-20
size WxHxD, cm	58x44x8	82×45.2×10.5	92.7x40x5.5
Weight, kg	5.4	9.45	6.6
brand owner	Noirot, France	Ballu Industrial Group, China	Glen Dimplex Nordic AS, Norway
country of origin	France	China	Norway
warranty, years	6	2	five
estimated service life, years	20	15	20
other options
frost protection	there is	not	there is
remote control control	not	there is	not
timer	not	there is	not
average cost, rub.
	4100	4200	4100

Analysis of convector models based on the information given in the table:

• the European models of the Noirot and Nobo brands have less attractive designs and performance than the Chinese model Ballu. The latter also benefits from the point of view of functionality – this convector is controlled by a remote control, while European models have only mechanical control;
• the “Ballu” and “Noirot” models are equipped with a solid silumin (aluminum alloy) heating element, which is more efficient and quiet in operation than the cermet ribbed heating element in the Nobo design, the operation of which will be accompanied by a characteristic crackling for the reasons described above;
• two preset operating modes (with half and full power) are present in the functions of only one device – the Ballu convector. It should be noted that this type of heaters, by and large, does not need preset power modes – their task is to maintain a given temperature range in the room, using the power required for this;
• only the Ballu model is equipped with a timer for 8 hours, which allows you to set the device to turn on after a certain period of time;
• the “frost protection” function, in which the room temperature will be maintained at least + 5 ° С, is available only for the described devices of European brands;
• the longest warranty period is provided by European convector manufacturers;
• models of the brands “Noirot” and “Ballu” allow both wall and floor installation of devices, moreover, the necessary set for floor installation is included in the standard set of the Ballu convector and, most often, is not included in the standard equipment of the Noirot. It should be noted that the Noirot heater is not equipped with a rollover shutdown sensor, but the Ballu convector has such a sensor. The described device of the “Nobo” brand, with equal power with the other two models participating in this review, differs in the greatest length and smaller thickness (depth), and therefore its design does not allow for floor installation.

Noirot Spot E-3 1500

(*) – In the absence of power modes, the Noirot convector is equipped with preset modes “comfortable” and “economical”. The first one is intended for use in the daytime; when activated, the device will maintain a constant temperature level in the room, which was set by the user. “Economy” mode is intended for operation of the heater at night – when it is activated, the convector maintains the temperature level in the room by 3 ° C below the “comfortable” level.

Ballu Plaza BEP / E-1500

Conclusion: It is difficult to make an unambiguous choice among the described models and brands of convectors, given that their cost is almost the same. From the point of view of design and remote control capabilities, the Ballu model is attractive, but from the point of view of reliability and safety, the advantage of the French brand Noirot is undoubted, therefore the Noirot Spot E-3 1500 model is recognized according to the results of the survey as the most successful solution to heating problems using a convector.

Nobo C4E15

How to choose a convector

The power when choosing a model suitable for this criterion depends on the thermal characteristics and the size of the room in which the device is supposed to be installed. If the convector will be used as an additional source of heating in the cold season or in the off-season, then its power is calculated by multiplying the volume of the room by 25 W / m², if the convector is the only source of heat, then you need to multiply the volume by 40 W / m². For example, for auxiliary heating of a 19 m2 room² with a ceiling height of 2.7 m, i.e. volume of 51.3 m³, a convector with a capacity of at least 1285.5 W is required (19×2.7×25 = 1285.5). Those. for a room with a volume of 51.3 m³ the optimal choice would be a 1500 W device, with a small power reserve in case of severe frosts.

When choosing, preference should be given to the brands of the largest manufacturers that provide long warranty periods not from scratch – their products really have high performance characteristics that do not change over many years of using the device. Make sure that this convector model must be equipped with an electronic thermostat, an overheating sensor and a rollover shutdown function for floor appliances. Convenient will be control from the remote control and the presence of a timer that allows you to set the switching on of the convector at a certain time. Among the types of heating elements that convectors are equipped with, the best option would be a solid aluminum element..

To heat rooms with a high level of humidity, such as a bathroom and a kitchen, convectors with a moisture protection class of at least IP 24 will be needed. However, direct contact of convection heaters with water is not allowed!

Of course, when inspecting the model offered by the seller, its case should not have any dents and scratches, paint stains, sharp edges and geometry violations. All screws holding the housing elements together must be flush. Any external defects indicate poor assembly quality of the device, damage caused during transportation.

When choosing a convector, you should know that:

• any convection electric heater dries the air and there are no “improvements”, except for equipping the device with a container with evaporated water (water must be refilled periodically!);
• air convection due to its heating will inevitably contribute to the rise and constant presence of dust in the atmosphere of the room, its accumulation between the plates of the heating element. Any statements like “this convector model does not accumulate dust” are not true;
• The efficiency of any electric heating device is close to 100%, so you do not need to take on faith statements like “The efficiency of this convector is higher than that of the others.”.

Finally – installation and operation

When installing the convector’s mounting frame on the wall and when installing the legs (wheels) on its body, follow the manufacturer’s instructions for the given model of the device. The place for installing the device should be chosen with great care: the minimum distance from the floor to the lower edge of its body is 150 mm; from side walls to any object or wall – 250 mm; from the top edge to any object above it – at least 450 mm. Failure to comply with these requirements, as well as full or partial covering of the body of a working convector with some material, will trigger the overheating sensor and turn off the heating function. Accordingly, it is absolutely impossible to install a “high” convector under window openings and dry things on its body! For installation under windows, only skirting convector models are suitable.

Periodically, it is necessary to remove dust from the external panels of the device with a damp cloth, after turning it off and making sure that the case is cool. To remove dust from the heating element, use a vacuum cleaner with a short narrow nozzle..