How to calculate electric floor heating
Have you decided to improve the heating of your home or completely abandon heating with batteries? Now for these purposes it is customary to use various. If for some reason (and there may be many) the water version did not suit you, the electric heating system will cope with this task. The calculation of a warm floor with such an active element, as well as its device, has its own characteristics. And for all the work to go smoothly, you need to understand them well. Let's start with the device.
Structural elements
The electric floor heating system consists of several interconnected parts. These include:
- thermostat;
- temperature sensor;
- power cable;
- heating element.
It functions in this way: the rest of the components are connected to the thermostat, which is placed in the wall through the power (mounting) wires. The heating element and temperature sensor are mounted in the floor. The first of them heats, and the second controls the temperature.
Most often, three types of heating elements are used in practice:
- mesh mat;
- heating cable.
Film and mat are less demanding for installation. They can be laid under a layer of tile adhesive even with a thickness of several millimeters. Therefore, they are ideal for installation under a tile. And the infrared film system can generally be placed directly under parquet or laminate.
With the cable version, things are a little more complicated. Firstly, such a device must be filled with a screed, and secondly, the pitch of the turn must be calculated during installation. In addition, the cable itself is divided into several varieties.
Cable varieties
A single core cable heating element or a two core equivalent can be used for your floor. Single-core - the simplest, cheapest and most inconvenient to use. One of its main drawbacks is the difficulty in calculation and installation. It arises from the need to bring both ends of the cable to one place. That is, it must be laid in such a way as to finish near the connection point to the thermostat.
An equally significant minus is the intense electromagnetic field along the entire length of the wire. It is considered harmful to human health. For this reason, systems with a single-core element are not recommended for use in residential premises.
Two-wire is a little more expensive, but there are fewer difficulties with it. The arrangement of wires for supply and return of current in one cable solves both voiced problems. it is enough to take into account the geometry of the room, and the induction field is extinguished by the movement of current in different directions.
Now you can proceed directly to the preparation of calculations.
Calculation features
The main parameters that affect the result are the area and type of building for which it will be, as well as the mode of use of the system. Each of them in its own way will be reflected in the required heating power.
Square
For the calculation of the electric floor, only the free space of the room is taken into account. It cannot be laid under furniture and large household appliances for several reasons:
- insufficient ventilation and, as a result, possible overheating of the system;
- the negative impact of constant heat on the installed objects themselves.
Therefore, the area on which you plan to place such items will need to be subtracted from the total number of square meters of the room.
Room type and heating mode
Each part of the building has its own heat loss indicators. Accordingly, the heating power to compensate for them will also differ. Significant adjustments will also be made by the mode in which it is planned to use the system - the main heating or additional. At this stage, it is better to show maximum attention in order to take into account all the subtleties and not miscalculate with the choice.
You will have to choose from average power indicators. If the underfloor heating is the main heating, they should be in the range of 150–180 W / m 2. It can be used as the main source of heat only if the “clean” laying area is at least 70% of the total. If he is only an assistant, 110–140 W / m 2 is enough. The same data exists for different types of rooms in a comfortable mode:
- room, kitchen - 120 W / m 2;
- bathroom - 140 W / m 2;
- glazed loggia or warm balcony - up to 180 W / m 2.
However, if your apartment is located on the ground floor, or for some other reason there was an unheated room under it, all indicators need to be increased by 15–20%.
Separately, it should be noted that these figures refer to well-insulated buildings. With too much heat loss, it is worth thinking about the efficiency of installing such heating. Even if these indicators are within the normal range, it is advisable to additionally insulate the slab under the floor. Thus, it will turn out to direct the action of the system to increase the air temperature in the room, and not the concrete in the ceiling.
Calculation formulas
We turn to the main issue - a warm floor with an electric heating element. But here everything is very simple. To determine the power of your system, it is enough to multiply the power of one m 2 by the area that it will occupy.
The length of the cable is usually already measured in the kit for the given parameters of power and coverage area. The recommended distance between cable turns is from 5 to 20 cm. If you want to be more precise, use the following formula: h=S*100/L. As you probably guessed, h is the stride width, S is the area, and L is the total length of the cable.
To make the calculation process even easier, you can use a special calculator for electric underfloor heating. Just fill in all the required fields, and the program will perform the necessary calculations and give you the final result.
