Operating principle of an electric convector

An electric convector is a heating household electrical appliance that raises the air temperature in a room through convection. It is an indispensable tool in case of a short-term drop in temperature during an unheated period to maintain a comfortable microclimate in a living space.

What is a convector

The convector is one of the most popular heating devices for domestic premises and offices. This article will help you answer the question of what makes it so.

Operating principle of the convector

As stated in the preamble, the operation of the device is based on the principle of convection or natural circulation of air flows. The device heats the cold air entering the convector from below using a heating element. After this, the heated flows leave the device through slots made in the upper part of the body. Warm air spreads in different directions and, as it cools, gradually sinks, where it again enters the capture zone. This ensures natural circulation, which quickly increases the temperature in the room.

Convector device

The device has a fairly simple design.At the bottom of the case there are openings for the incoming flow of cold air. There are slots on top for the distribution of hot flow. Inside are:

• heating element (open or closed type);
• temperature sensor;
• Control block.

The latter turns the device on/off, sets the operating temperature, and also switches off due to overheating. The temperature sensor is connected to a control circuit, which, when determining the temperature level corresponding to the set one, sends a signal to turn off the heating element. After the room has cooled down, the convector turns on again.

There are three types of heating elements: heating elements, needle and monolithic.

The control can be carried out by means of a mechanical thermostat or be implemented in an electronic circuit.

REFERENCE! Convectors are available in floor and suspended versions. Floor-standing models pose a potential danger - if they tip over, there is a risk of fire. Therefore, almost all such devices are equipped with a rollover sensor and an emergency shutdown system.

Advantages and disadvantages of a convector

The device has a number of advantages:

• ease of installation and operation;
• long service life without the need for special maintenance;
• low cost;
• the ability to work autonomously without constant human presence and control;
• high efficiency (up to 90–95%);
• no noise during operation;
• not demanding on the quality of the electrical network - capable of trouble-free operation at voltages in the range from 150 to 240 V;
• does not dry out the surrounding air;
• tolerates contact and splashes and can be used in wet conditions;
• the body does not heat up to high temperatures, as a result of which the possibility of getting burned is excluded;
• high maintainability;
• possibility of flexible adjustment of room temperature;
• high level of security.

Unfortunately, the device is not without some disadvantages, including:

• significant energy consumption;
• may be a source of unpleasant odor if dust gets on an open heating element;
• limited scope - effective only in small rooms (up to 30 square meters) with low ceilings.

Convector power calculation

When choosing such a device, the main performance characteristic is power. It is determined based on the size and configuration of the room in which the heater is supposed to be installed. There are several approaches to determining the required power.

Based on the area of ​​the room

It is generally accepted that for a room with one door, one window and a flow height of 2.5 m, 1 kW per 10 m is required² area. This approach is approximate and subject to adjustment through correction factors (k). For example, if the room is located in the corner of the building, that is, it is surrounded on both sides by external walls, then when calculating the power, the correction k = 1.1 is applied.

If the room has good thermal insulation, you can use a reduction factor of 0.8 or 0.9.

Example 1. It is necessary to calculate the power of a convector for installation in a room with an area of ​​25 m², with low ceilings (approximately 2.5 m), located in the corner of a building with walls that have double thermal insulation. The room has one window and one door.

Then the power P will be calculated by the formula: P = 1 kW * (25 m²/10 m²) * 1.1 * 0.8 = 2.2 kW.

By room volume

This approach allows you to more accurately determine the power of the device, since it takes into account the height of the heated space. The idea is that heating each cubic meter of air requires 40 W of device power. To determine the final value, the same coefficients as described in the previous case are applied. It is also worth clarifying the power value if there is more than 1 window in the room - each subsequent one requires an increase in the power of the device by 10%.

Example 2. You need to select the power for a living room located in the middle part of a building with well-insulated walls. The living room has 2 windows, the height of the room is 2.7 m, the length is 7 m, and the width is 4 m.

Let's calculate the power:

P = 2*2.7*7*0.8*40 = 1209.6 W = 1.21 kW.

As an additional source of heating

If the house has central heating, the power of which is not enough to maintain a comfortable temperature, a convector can be used as an additional heat source.

In this case, a power of 40±10 W is required for each square meter of area or 15–20 W for each cubic meter.