Calculation of the power of the heating floor heating cable

When choosing a cable underfloor heating system as the main or additional heating system, it is first necessary to determine the power of the heating cable for this system. It is very important to perform the correct power calculation so that the installed heating system functions correctly and fully complies with the requirements that apply to it.

The initial data for the calculation

There is no single rule by which it is possible to calculate the required power of a heating cable for a warm floor. When calculating the power, it is necessary to take into account several factors that significantly affect the functioning of the warm floor.

Therefore, the first step in performing the calculation will be to refine the source data:

1) The required degree of warming the rooms

In this case, it is necessary to clarify for what purposes a heated floor is used - as the main source of heat or as an additional or backup in a particular room.

If the electric underfloor heating is used as an independent source of heating, then accordingly its power should be such as to ensure a comfortable temperature in the room, taking into account possible temperature fluctuations.

As an additional source of heating, the task of the warm floor is to compensate for the possible lack of power of the main heating system or to ensure comfort in the room if there is a problem of insufficient heating of the floor covering.

The backup function of the underfloor heating is necessary in case of a short-term shutdown of the main heating system, for example, for the period of elimination of its malfunction or for a while in the central heating supply. In this case, the underfloor heating should provide the minimum allowable temperature in the room.

2) The area of ​​the heated room

To calculate the floor heating system, it is necessary to take into account the free area, that is, the one that is not occupied by furniture and other interior elements. It is also necessary to take into account the height of the ceilings in the room, since for a room of the same area, but with a greater height of the ceiling, it is necessary to spend more electricity to heat the room.

3) type of flooring and method of installation of the heating cable. Each floor covering individually and accordingly has its own values ​​of heat sensitivity and thermal conductivity. In this case, the location of the room is important, in particular the presence or absence of heating from above, below and in adjacent rooms.

More related links:

How the electric heat-insulated floor is arranged and works

Modern types of electric underfloor heating

Installation of electric underfloor heating for tiles

Choosing the power of a heating floor heating cable

When choosing the power of the heating cable, we are talking about the power of the electric floor heating system as a whole. Based on the total power, you can calculate how many meters of heating cable of one capacity or another are required.

Often a number of complex formulas are given for calculating the required total cable power, but their application does not guarantee an accurate result, since the initial data characterizing the room are indicative.

We give an approximate recommended range of the total power of the heating cable per one square meter of free space, which will be relevant for most residential premises:

• 100-140 W / sq. m for the use of underfloor heating as an additional or backup source of heating;

• 140-180 W / sq. m for the underfloor heating system, which is the main source of heating;

• 180-220 W / sq.m for cold rooms (glazed loggias, pools, bath rooms).

For example, to implement an additional room heating system with an area of ​​20 square meters. m, of which 12 square meters. m not occupied by furniture, it is necessary to mount a warm floor with a capacity of 1200-1700 watts. That is, only the usable floor area is taken for calculation.

In the given range, a lower value is relevant for an area with a relatively warm, temperate climate, respectively, a larger value - for a cold climate.

As mentioned above, it is necessary to take into account not only the area, but also the height of the room. The given power range is relevant for domestic premises with a standard ceiling height of 2.5-3 m.

It is also necessary to consider the type of flooring and the method of installation of the cable. Firstly, in order to correctly select the total power of the underfloor heating system. If the flooring is not very cold, then the above power ranges will be relevant.

If the floors installed in the room are cold, then in this case it is more advisable not to increase the power of the warm floor, but to put a heat-insulating material under the heating cable, which will reduce heat loss and prevent excessive cooling of the floor covering. This recommendation is especially relevant for private homes in which the flooring is located directly on cold soil or foundation.

Secondly, for the correct choice of power of the cable itself. Manufacturers of flooring, as a rule, indicate the permissible temperature for a particular material. That is, the cable must be chosen with such a power that the installed floor covering (laminate, linoleum, ceramic tile, carpet, porcelain stoneware, etc.) does not undergo destruction due to overheating.

From this it also follows that the possible maximum power of a warm floor depends on the choice of the type of flooring. For example, under a laminate, the permissible temperature for heating a warm floor should not exceed 26 grams.

This temperature will not provide sufficient heating of the room, since on the surface of the laminate it will be below 26 g. Therefore, with such a floor covering, a warm floor can be considered solely as an additional source of heating.

When choosing a warm floor, it is necessary to take into account the step recommended by the manufacturer for laying the heating cable. Based on the recommended installation step, the required total power, as well as the power of the cable to be laid, you can tentatively assess the possibility of using one or another type of cable.

If, taking into account the minimum installation step, it is not possible to place the required amount of heating cable, then it is necessary to choose a more powerful cable, but its heating temperature should not exceed the permissible temperature for a particular type of floor covering.

It should also be mentioned that the electric underfloor heating is always equipped temperature sensor and thermostat. Therefore, there is no need for accurate calculations - the room temperature will be automatically adjusted in accordance with the set values.

In this case, the main thing is that there should be enough power, but at the same time not to make too much headroom. On the one hand, a large supply is good because the room warms up quickly, but on the other hand, to maintain the set temperature, the thermostat will very often turn the heating cable on and off, which will reduce its service life.

See also:How to save electricity at home