In order to avoid unnecessary costs and technological errors that can lead to a partial or complete alteration of the system with your own hands, the calculation of a water-heated floor is made in advance, before laying. The following inputs are required:
- The materials from which the housing is built;
- Availability of other sources of heating;
- Room area;
- The presence of external insulation and the quality of the glazing;
- Regional location of the house.
You also need to determine what maximum air temperature in the room is required for the comfort of residents. On average, it is recommended to design the contour of the water floor at the rate of 30-33 ° C. However, such high performance during operation may not be needed, a person feels most comfortable at temperatures up to 25 degrees.
In the case when additional heat sources are used in the house (air conditioner, central or autonomous heating, etc.), the calculation of the warm floor can be oriented to the average maximum values of 25-28 ° С.
Advice! It is strongly not recommended to connect warm water floors with your own hands directly through the central heating system. It is advisable to use a heat exchanger. The ideal option is completely autonomous heating and connecting underfloor heating through a collector to the boiler.
The efficiency of the system directly depends on the material of the pipes through which the coolant will move. 3 types are used:
- Copper;
- Polyethylene or cross-linked polypropylene;
- Metal-plastic.
Copper pipes have maximum heat transfer, but a rather high cost. Polyethylene and polypropylene pipes have low thermal conductivity, but are relatively cheap. The best option in terms of price and quality is metal-plastic pipes. They have a low heat transfer consumption and an acceptable price.
Experienced specialists primarily take into account the following parameters:
- Determining the value of the desired t in the room.
- Correctly calculate the heat loss of the house. To do this, you can use calculator programs or invite a specialist, but it is also possible to make an approximate calculation of heat losses yourself. An easy way to calculate a warm water floor and heat loss in a room is the average value of heat loss in a room - 100 W per 1 sq. meter, taking into account the ceiling height of not more than 3 meters and the absence of adjacent unheated premises. For corner rooms and those in which there are two or more windows, heat losses are calculated based on a value of 150 W per 1 sq. meter.
- Calculation of how much heat loss of the circuit will be for each m2 of the area heated by the water system.
- Determination of heat consumption per m2, based on the decorative material of the coating (for example, ceramics have a higher heat transfer than laminate).
- Calculation of surface temperature taking into account heat loss, heat transfer, desired temperature.
On average, the required power for every 10 m2 of paving area should be about 1.5 kW. In this case, point 4 in the above list must be taken into account. If the house is well insulated, the windows are made of a high-quality profile, then 20% of the power can be allocated for heat transfer.
Accordingly, with a room area of 20 m2, the calculation will take place according to the following formula: Q = q * x * S.
3kW*1.2=3.6kW, where
Q is the required heating power,
q \u003d 1.5 kW \u003d 0.15 kW is a constant for every 10m2,
x = 1.2 is the average heat loss coefficient,
S is the area of the room.
Before starting the installation of the system with your own hands, it is recommended to draw up a plan, accurately indicate the distance between the walls and the presence of other heat sources in the house. This will allow you to accurately calculate the power of the water floor. If the area of \u200b\u200bthe room does not allow the use of one circuit, then it is correct to plan the system, taking into account the installation of the collector. In addition, you will need to mount a cabinet for the device with your own hands and determine its location, distance to walls, etc.
How many meters is the optimal length of the circuit
H2_2Often there is information that the maximum length of one circuit is 120 m. This is not entirely true, since the parameter directly depends on the diameter of the pipe:
- 16 mm - max L 90 meter.
- 17 mm - max L 100 meter.
- 20 mm - max L 120 meter.
Accordingly, the larger the diameter of the pipeline, the lower the hydraulic resistance and pressure. And that means a longer contour. However, experienced craftsmen recommend not to "chase" the maximum length and choose pipes D 16 mm.
You also need to take into account that thick pipes D 20 mm are problematic to bend, respectively, the laying loops will be more than the recommended parameter. And this means a low level of system efficiency, because. the distance between the turns will be large, in any case, you will have to make a square contour of the cochlea.
If one circuit is not enough to heat a large room, then it is better to mount a double-circuit floor with your own hands. In this case, it is strongly recommended to make the same length of the contours so that the heating of the surface area is uniform. But if the difference in size still cannot be avoided, an error of 10 meters is allowed. The distance between the contours is equal to the recommended step.
Hydraulic pitch between coils
The uniformity of surface heating depends on the pitch of the coil. Usually 2 types of pipe laying are used: snake or snail.
The snake is preferably done in rooms with minimal heat loss and a small area. For example, in a bathroom or corridor (since they are located inside a private house or apartment without contact with the outside environment). The optimal loop pitch for a snake is 15-20 cm. With this type of laying, the pressure loss is approximately 2500 Pa.
Snail loops are used in spacious rooms. This method saves the length of the circuit and makes it possible to evenly heat the room, both in the middle and closer to the outer walls. The loop pitch is recommended within 15-30 cm. Experts say that the ideal step distance is 15 cm. The pressure loss in the cochlea is 1600 Pa. Accordingly, this do-it-yourself installation option is more profitable in terms of system power efficiency (you can cover a smaller usable area). Conclusion: the snail is more efficient, the pressure drops less in it, respectively, the efficiency is higher.
The general rule for both schemes is that closer to the walls, the step should be reduced to 10 cm. Accordingly, from the middle of the room, the contour loops are gradually compacted. The minimum laying distance to the outer wall is 10-15 cm.
Another important point - you can not lay the pipe on top of the seams of concrete slabs. It is necessary to draw up a diagram in such a way that the same location of the loop between the joints of the plate on both sides is observed. For do-it-yourself installation, you can draw a diagram in advance on a rough screed with chalk.
How many degrees are allowed for temperature changes
System design, in addition to heat and pressure losses, implies temperature differences. The maximum difference is 10 degrees. But it is recommended to focus on 5 ° C for uniform operation of the system. If the desired comfort temperature of the floor surface is 30 °C, then the direct pipeline should supply about 35 °C.
Pressure and temperature, as well as their losses, are checked during pressure testing (checking the system before finishing pouring the finishing screed). If the design is done correctly, then the specified parameters will be accurate with an error of no more than 3-5%. The higher the difference t, the higher the power consumption of the floor.
