Water heat-insulated floors contour length. Underfloor heating design: general recommendations

It covers such topics as: the maximum length of a water floor heating circuit, the location of pipes, optimal calculations, as well as the number of circuits with one pump and whether two are needed the same.

The popular wisdom calls for measuring seven times. And you can't argue with that.

In practice, it is not easy to embody what has been repeatedly scrolled in your head.

In this article we will talk about the work associated with the communications of a warm water floor, in particular, we will pay attention to the length of its contour.

If we plan to install a water heat-insulated floor, the length of the contour is one of the first questions that need to be dealt with.

Arrangement of pipes

The underfloor heating system includes a considerable list of elements. We are interested in pipes. It is their length that defines the concept of "maximum length of a warm water floor." It is necessary to lay them taking into account the characteristics of the room.

Based on this, we get four options, known as:

snake;
double snake;
corner snake;
snail.

If you do the right styling, then each of the listed types will be effective for heating the room. The footage of the pipe and the volume of water can be (and most likely will be). This will determine the maximum length of the water floor heating circuit for a particular room.

Main calculations: water volume and pipeline length

There are no tricks here, on the contrary - everything is very simple. For example, we have chosen the snake option. We will use a number of indicators, among which is the length of the contour of a water-heated floor. Another parameter is diameter. Pipes with a diameter of 2 cm are predominantly used.

We also take into account the distance from the pipes to the wall. Here it is recommended to fit within the range of 20-30 cm, but it is better to place the pipes clearly at a distance of 20 cm.

The distance between the pipes themselves is 30 cm.The width of the pipe itself is 3 cm.In practice, we get a distance between them of 27 cm.
Now let's move on to the area of \u200b\u200bthe room.

This indicator will be decisive for such a parameter of a warm water floor as the length of the contour:

Let's say our room is 5 m long and 4 m wide.
Laying the pipeline of our system always starts from the smaller side, that is, from the width.
To create the base of the pipeline, take 15 pipes.
A gap of 10 cm remains near the walls, which then increases by 5 cm on each side.
The section between the pipeline and the collector is 40 cm. This distance exceeds those 20 cm from the wall, which we talked about above, since in this section you will have to install a water drainage channel.

Our indicators now make it possible to calculate the length of the pipeline: 15x3.4 \u003d 51 m. The entire contour will take 56 m, since we should also take into account the length of the so-called. collector section, which is 5 m.

The length of the pipes of the entire system must fit into the permissible range - 40-100 m.

amount

One of the following questions: what is the maximum length of the water floor heating circuit? What to do if the room requires, for example, 130 or 140-150 m of pipe? The way out is very simple: it will be necessary to make more than one contour.

The main thing in the operation of a water-heated floor system is efficiency. If, according to calculations, we need 160 m of pipe, then we make two circuits of 80 m each.After all, the optimal length of the water floor heating circuit should not exceed this indicator. This is due to the ability of the equipment to create the required pressure and circulation in the system.

It is not necessary to make the two pipelines absolutely equal, but it is also not desirable for the difference to be noticeable. Experts believe that the difference may well reach 15 m.

Maximum length of the water floor heating circuit

To determine this parameter, we must take into account:

The listed parameters are determined, first of all, by the diameter of the pipes used for the warm water floor, the volume of the coolant (per unit of time).

In the installation of a warm floor, there is a concept - the effect of the so-called. locked hinge. This is a situation where circulation through the loop will be impossible, regardless of the pump power. This effect is inherent in a situation of pressure loss, calculated at 0.2 bar (20 kPA).

In order not to confuse you with long calculations, we will write several recommendations, proven by practice:

A maximum circuit of 100 m is used for pipes with a diameter of 16 mm made of metal-plastic or polyethylene. Ideal - 80 m
120 m contour - limit for 18 mm XLPE pipe. However, it is best to limit yourself to a range of 80-100m.
With a 20 mm plastic pipe, you can make a contour of 120-125 m

Thus, the maximum pipe length for a warm water floor depends on a number of parameters, the main of which is the pipe diameter and material.

Are two identical ones needed and possible?

Naturally, the ideal situation will look when the loops are of the same length. In this case, you will not need any settings, searches for a balance. But this is more in theory. If you look at practice, it turns out that it is not even advisable to achieve such an equilibrium in a warm water floor.

The fact is that it is often necessary to lay underfloor heating in an object consisting of several rooms. One of them is emphatically small, for example, a bathroom. Its area is 4-5 m2. In this case, a reasonable question arises - is it worth adjusting the entire area for a bathroom, splitting it into tiny areas?

Since this is not advisable, we come to another question: how not to lose on pressure. And for this, such elements as balancing fittings were created, the use of which consists in equalizing the pressure losses along the circuits.

Again, calculations can be used. But they are complicated. From the practice of carrying out work on the installation of a warm water floor, we can safely say that the spread in the size of the contours is possible within 30-40%. In this case, we have every chance to get the maximum effect from the operation of a warm water floor.

Despite the considerable amount of materials on how to make a water floor yourself, it is better to turn to specialists. Only foremen can evaluate the working area and, if necessary, “manipulate” the pipe diameter, “cut” the area and combine with the laying step when it comes to large areas.

Quantity with one pump

Another frequently asked question: how many circuits can operate on one mixing unit and one pump?
The question, in fact, needs to be concretized. For example, to the level - how many loops can be connected to the collector? In this case, we take into account the diameter of the collector, the volume of the coolant passing through the node per unit of time (the calculation is in m3 per hour).

We need to look at the data sheet of the node, where the maximum throughput factor is indicated. If we carry out the calculations, then we will get the maximum indicator, but we cannot count on it.

One way or another, the maximum number of circuit connections is indicated on the device - as a rule, 12. Although, according to calculations, we can get both 15 and 17.

The maximum number of outputs in the collector does not exceed 12. However, there are exceptions.

We saw that installing a warm water floor is a very troublesome business. Especially in that part of it, where it comes to the length of the contour. Therefore, it is better to contact specialists so as not to redo the not entirely successful styling later, which will not bring the efficiency that you expected.

Underfloor heating is one of the most efficient and cost-effective ways to heat a room. Judging from the point of view of operating costs, then a water "warm floor" looks preferable, especially if the house already has a water heating system. Therefore, despite the rather high complexity of installation and debugging of water heating, it is often chosen.

Work on a water "warm floor" begins with its design and calculations. And one of the most important parameters will be the length of the pipes in the circuit being laid. The point here is not only, and not so much in the cost of material - it is important to ensure that the length of the circuit does not exceed the permissible maximum values, otherwise the operability and efficiency of the system is not guaranteed. The calculator for calculating the length of the contour of a water-heated floor, located below, can help with the necessary calculations.

Several necessary explanations on working with the calculator are given below.

Warm floors are an excellent solution for the improvement of your home. The floor temperature directly depends on the length of the floor heating pipes hidden in the screed. The pipe in the floor is laid in loops. In fact, from the number of loops and their length, the total length of the pipe is added. It is clear that the longer the pipe in the same volume, the warmer the floor. In this article, we will talk about the restrictions on the length of one contour of the warm floor.

Approximate design characteristics for pipes with a diameter of 16 and 20 mm are: 80-100 and 100-120 meters, respectively. These data are approximate for approximate calculations. Let's take a closer look at the process of installing and pouring underfloor heating.

The consequences of exceeding the length

Let's figure out what consequences an increase in the length of the underfloor heating pipe can lead to. One of the reasons is an increase in hydraulic resistance, which will create an additional load on the hydraulic pump, as a result of which it may fail or it may simply not be able to cope with the task assigned to it. Resistance calculation consists of many parameters. Conditions, styling parameters. The material of the pipes used. There are three main ones: loop length, number of bends and heat load on it.

It is worth noting that the heat load increases with increasing loop. The flow rate and hydraulic resistance also increase. There are restrictions on the flow rate. It should not exceed 0.5 m / s. If we exceed this value, various noise effects may occur in the piping system. The main parameter, for the sake of which this calculation is done, also increases. The hydraulic resistance of our system. There are restrictions on it too. They are 30-40 kP per loop.

The next reason is that with an increase in the length of the underfloor heating pipe, the pressure on the pipe walls increases, causing this section to elongate when heated. The pipe in the screed has nowhere to go. And it will begin to taper at its weakest point. The restriction can cause blockage of the flow in the heating medium. Pipes made from different materials have different expansion coefficients. For example, polymer pipes have a very high coefficient of expansion. All these parameters must be taken into account when installing a warm floor.

Therefore, it is necessary to fill the underfloor heating screed with pressed pipes. It is better to pressurize with air at a pressure of about 4 bar. Thus, when you fill the system with water and start heating it, the pipe in the screed will be where it will expand.

Optimal pipe length

Considering all of the above reasons, taking into account the corrections for the linear expansion of the pipe material, we take as a basis the maximum length of the underfloor heating pipes per circuit:

The table shows the optimal dimensions of the underfloor heating that are suitable for all modes of thermal expansion of pipes in various modes of operation.

Note: In residential buildings, a 16 mm pipe is sufficient. A larger diameter should not be used. This will lead to unnecessary waste on energy.

The main argument in favor of the "warm floor" system is the increased comfort of a person's stay in the room, when the entire surface of the floor acts as a heating device. The air in the room warms up from the bottom up, while at the floor surface it is somewhat warmer than at a height of 2-2.5 m.

In some cases (for example, when heating shopping malls, swimming pools, gyms, hospitals) underfloor heating is preferred.

The disadvantages of underfloor heating systems include the relatively high cost of equipment in comparison with radiator systems, as well as increased requirements for the technical literacy of installers and the quality of their work. With the use of high-quality materials and adherence to the installation technology of a well-designed water underfloor heating system, there are no problems with its subsequent operation.

The heating boiler operates on radiators at 80/60 ° C. How to connect the "warm floor" correctly?

To obtain the design temperature (as a rule, not higher than 55 ° C) and the specified flow rate of the coolant in the "warm floors" circuit, pumping and mixing units are used. They form a separate low-temperature circulation circuit, into which hot heating medium from the primary circuit is mixed. The amount of the added heating agent can be set both manually (if the temperature and flow rate in the primary circuit are constant), and automatically using thermostats. To fully realize all the advantages of a "warm floor" allow the pumping and mixing units with weather compensation, in which the temperature of the coolant supplied to the low-temperature circuit is adjusted depending on the outside air temperature.

Is it allowed to connect the "warm floor" to the central heating system or hot water supply of an apartment building?

It depends on local legislation. For example, in Moscow, the installation of underfloor heating from common building water supply and heating systems is excluded from the list of permitted types of re-equipment (Decree of the Moscow Government No. 73-PP dated February 8, 2005). In a number of regions, interdepartmental commissions deciding the issue of approving the installation of a "warm floor" system require additional expertise and calculated confirmation that the device of a "warm floor" will not lead to a disruption in the operation of general building engineering systems (see "Rules and regulations for the technical operation of housing fund ", p. 1.7.2).

From a technical point of view, connecting a "warm floor" to a central heating system is possible provided that a separate pumping and mixing unit is installed with limited pressure of the coolant returned to the house system. In addition, if there is an individual heating point in the house equipped with an elevator (jet pump), the use of plastic and metal-plastic pipes in heating systems is not allowed.

What is the best material to use as a floor covering in a "warm floor" system? Can parquet floors be used?

Best of all, the effect of "warm floor" is felt with floor coverings made of materials with a high coefficient of thermal conductivity (ceramic tiles, concrete, self-leveling floors, baseless linoleum, laminate, etc.). If carpet is used, it must have a "suitability mark" for use on a warm substrate. Other synthetic coatings (linoleum, relin, laminated boards, plastic compound, PVC tiles, etc.) must have a "sign of absence" of toxic emissions at an elevated base temperature.

Parquet, parquet boards and boards can also be used as a "warm floor" covering, but the surface temperature should not exceed 26 ° C. In addition, a safety thermostat must be included in the mixing unit. The moisture content of natural wood flooring materials should not exceed 9%. Work on laying a parquet or plank floor is allowed only at a room temperature of at least 18 ° C and 40-50% humidity.

What should be the temperature on the surface of the "warm floor"?

The requirements of SNiP 41-01-2003 "Heating, Ventilation and Air Conditioning" (clause 6.5.12) with respect to the surface temperature of the "warm floor" are given in the table. It should be noted that foreign regulatory documents allow for slightly higher surface temperatures. This must be taken into account when using calculation programs developed on their basis.

How long can the underfloor heating pipes be?

The length of one loop of the "warm floor" is dictated by the pump power. If we talk about polyethylene and metal-plastic pipes, then it is economically expedient that the loop length of a pipe with an outer diameter of 16 mm does not exceed 100 m, and with a diameter of 20 mm - 120 m. It is also desirable that the hydraulic pressure loss in the loop does not exceed 20 kPa. The approximate area occupied by one loop, subject to these conditions, is about 15 m2. With a larger area, collector systems are used, while it is desirable that the length of the loops connected to one collector be approximately the same.

What should be the thickness of the heat-insulating layer under the pipes of the "warm floor"?

The thickness of the insulation, limiting heat loss from the pipes of the "warm floor" in the "downward" direction, should be determined by calculation and largely depends on the air temperature in the design room and the temperature in the underlying room (or ground). In most Western design programs, heat losses "down" are assumed to be 10% of the total heat flux. If the air temperature in the design and the underlying room is the same, then this ratio is satisfied by a layer of expanded polystyrene with a thickness of 25 mm with a thermal conductivity coefficient of 0.035 W / (moK).

What pipes are better to use for the installation of the "warm floor" system?

Pipes for a "warm floor" device must have the following properties: flexibility, allowing the pipe to bend with a minimum radius to ensure the required laying pitch; the ability to maintain shape; low coefficient of resistance to the movement of the coolant to reduce the power of pumping equipment; durability and corrosion resistance, since access to pipes during operation is difficult; oxygen tightness (like any pipeline of the heating system). In addition, the pipe should be easy to machine with a simple tool and at a reasonable price.

The most widespread systems are "warm floor" systems made of polyethylene (PEX-EVOH-PEX), metal-plastic and copper pipes. Polyethylene pipes are less convenient to work with, since they do not retain their given shape, and when heated, they tend to straighten out ("memory effect"). Copper pipes, when embedded in a screed, must have a covering polymer layer in order to avoid alkaline action; moreover, this material is quite expensive. Reinforced-plastic pipes meet the requirements most fully.

Do I need to use a plasticizer when pouring a "warm floor"?

The use of a plasticizer allows you to make the screed more dense, without air inclusions, which significantly reduces heat losses and increases the strength of the screed. However, not all plasticizers are suitable for this purpose: most of those used in construction are air-entraining, and their use, on the contrary, will lead to a decrease in the strength and thermal conductivity of the screed. For "warm floor" systems, special non-entraining plasticizers are produced, based on finely dispersed flaky particles of mineral materials with a low coefficient of friction. Typically, the consumption of plasticizer is 3-5 l / m3 of mortar.

What is the point of using aluminum foil coated thermal insulation?

In cases where "underfloor heating" pipes are installed in an air gap (for example, in floors along logs), foiling of thermal insulation allows you to reflect most of the downward radiant heat flux, thereby increasing the efficiency of the system. Foil plays the same role in the construction of porous (gas or foam concrete) screeds.

When the screed is made of a dense cement-sand mixture, foiling of thermal insulation can be justified only as an additional waterproofing - the reflective properties of the foil cannot manifest themselves due to the absence of the "air - solid" boundary. It should be borne in mind that the layer of aluminum foil, poured with cement mortar, must necessarily have a protective coating of a polymer film. Otherwise, aluminum can be destroyed under the influence of a highly alkaline solution (pH \u003d 12.4).

How to avoid cracking of the "warm floor" screed?

The reasons for the appearance of cracks in the underfloor heating screed may be the low strength of the insulation, poor-quality compaction of the mixture during installation, the absence of a plasticizer in the mixture, or too thick screed (shrinkage cracks). The following rules should be adhered to: the density of the insulation (expanded polystyrene) under the screed must be at least 40 kg / m3; the mortar for the screed must be workable (plastic), the use of a plasticizer is mandatory; in order to avoid the appearance of shrinkage cracks, polypropylene fiber should be added to the solution at the rate of 1-2 kg of fiber per 1 m3 of solution. For power loaded floors, steel fiber is used.

Is waterproofing required for underfloor heating?

If a vapor barrier is not provided for in the architectural and construction part of the project, then with the "wet method" of installing the "warm floor" system along the ceilings, it is recommended to lay a layer of glassine on the leveled floor. This will help prevent the laitance from flowing through the overlap while the screed is being poured. If the project provides for an interfloor vapor barrier, then it is not necessary to arrange additional waterproofing. Waterproofing in wet rooms (bathrooms, toilets, showers) is arranged in the usual manner on top of the "warm floor" screed.

What should be the thickness of the damper tape installed around the perimeter of the room?

For rooms with a side length of less than 10 m, a 5 mm seam is sufficient. For other premises, the seam is calculated according to the formula: b \u003d 0.55 o L, where b is the seam thickness, mm; L is the length of the room, m.

What should be the step of laying the pipes of the "warm floor" loop?

The step of the loops is determined by calculation. It should be borne in mind that a loop pitch of less than 80 mm is difficult to implement in practice because of the small bending radius of the pipe, and a pitch of more than 250 mm is not recommended, as it leads to a noticeable uneven heating of the "warm floor". To facilitate the task of choosing the step of the loops, you can use the table below.

Is it possible to install heating only on the basis of the "warm floor" system, without radiators?

To answer this question in each specific case, it is required to make a heat engineering calculation. On the one hand, the maximum specific heat flux from the "warm floor" is about 70 W / m2 at an indoor air temperature of 20 ° C. This is sufficient to compensate for heat losses through enclosing structures made in accordance with thermal protection standards.

On the other hand, if we take into account the heat consumption for heating the outside air required by sanitary standards (3 m3 / h per 1 m2 of living space), then the capacity of the "warm floor" system may be insufficient. In such cases, it is recommended to use edge zones with elevated surface temperatures along the outer walls, as well as the use of "warm wall" sections.

How long after pouring the screed can the "warm floor" system be started?

The screed must have time to acquire sufficient strength. After three days under natural hardening conditions (without heating), it gains 50% strength, after a week - 70%. A full set of strength to the design grade occurs after 28 days. Based on this, it is recommended to start the "warm floor" no earlier than three days after pouring. It should also be remembered that the "warm floor" system solution is filled with floor pipelines filled with water at a pressure of 3 bar.

1. What temperature should be the coolant in the warm floor and how can its temperature be controlled?

The temperature should be no higher than 55 ° C, and in some cases no higher than 45 ° C.

To put it more precisely: the temperature should be in accordance with the temperature calculated in the project, which takes into account the need for a particular room for heat and the material from which the floor is made.

You can control the temperature with such a thermometer, or better than two.

One thermometer shows the temperature of the coolant at the underfloor heating supply (mixed water temperature), and the other shows the return temperature.

If the difference between the readings of the two thermometers is 5 - 10 o C, then your underfloor heating system is working correctly.

2. What should be the temperature on the underfloor heating surface?

The surface temperature of a working underfloor heating must not exceed the following values:

29 o C - in premises for long-term presence of people;

35 o C - in the border zones;

33 o C - in toilets, bathrooms.

3. What forms of pipe laying are used for underfloor heating?

Different forms are used for laying underfloor heating pipes: snake, corner snake, snail, double snake (meander).

Also, when laying one contour, you can combine these shapes.

For example, the edge zone can be positioned with a snake, and then the main part can be traversed with a snail.

4. What is the best installation for a warm floor?

For large rooms of a square, rectangular or round shape without geometric exclusivity, it is better to use a snail.

For small rooms, rooms with complex shapes or long rooms, use a snake.

5. What should be the laying step?

The laying step should be designed in accordance with the calculations.

For the marginal zones, a step of 10 cm is used.For other zones with a difference of 5 cm - 15 cm, 20 cm, 25 cm.But no more than 30 cm.

This limitation is due to the sensitivity of the person's foot.
With a larger pipe pitch, the leg begins to feel the temperature difference between the floor areas.

To do this, you can use a very simple formula: L \u003d S / N * 1.1where

S is the area of \u200b\u200bthe room or circuit for which the pipe length is calculated (m 2);
N - laying step;
1.1 - pipe stock of 10% for turns.

Do not forget to add the length of the pipe from the collector to the underfloor heating to the result obtained, including supply and return.

For example, consider a problem in which you need to calculate the length of a pipe for a room in which the floor occupies a useful area of \u200b\u200b12 m 2. The distance from the collector to the warm floor is 7 m. The pipe laying step is 15 cm (do not forget to translate into m).

Solution: 12 / 0.15 * 1.1 + (7 * 2) \u003d 102 m.

7. What is the maximum length of one circuit?

It all depends on the hydraulic resistance or pressure losses in a particular circuit, which, in turn, directly depend both on the diameter of the pipes used and on the volume of the coolant that is supplied through the cross section of these pipes per unit of time.

In the case of underfloor heating, (if you do not take into account the above factors), you can get the effect of the so-called locked loop. A situation in which no matter how powerful the pump you put on, circulation through this loop will be impossible.

In practice, it has been found that a pressure loss of 20 kPa or 0.2 bar just leads to this effect.

In order not to go into the calculations, here are some recommendations that we use in practice.
For a metal-plastic pipe with a diameter of 16 mm, we make a contour of no more than 100 m.We usually adhere to 80 m.
The same goes for polyethylene pipes. For 18 XLPE pipes, the maximum loop length is 120 m.In practice, we stick to 80 - 100 m. For 20 multilayer pipes, the maximum loop length is 120 - 125 m.

8. Can there be underfloor heating contours of different lengths?

The ideal situation is when all loops are the same length. There is no need to balance or adjust anything.

In practice, this can be achieved, but more often than not it is not advisable.

For example, there is a group of rooms at the facility where you need to make a warm floor. Among them there is also a bathroom, the usable floor area of \u200b\u200bwhich is 4 m 2. Accordingly, the length of the pipeline of this circuit together with the length of the pipes to the collector is only 40 m.
Is it really necessary to adjust all rooms to this length, dividing the usable area of \u200b\u200bthe remaining rooms by 4 m 2?

Of course not. It is not advisable. And then what is the balancing armature for, which is precisely designed to help equalize the pressure loss across the circuits?

Again, you can use the calculations, through which you can see to what maximum limit you can allow the spread of the lengths of pipes of individual circuits at a particular facility with this equipment.

But again, without immersing you in complex boring calculations, we will say that at our facilities we allow a variation in the lengths of pipes of individual circuits by 30 - 40%. Also, if necessary, you can "play" with the diameters of the pipes, the laying step and "cut" the area of \u200b\u200blarge rooms not into small or large, but into medium pieces.

9. How many circuits can be connected to one mixing unit with one pump?

Physically, this question is similar to the question: "How much cargo can you carry by car?"

What else would you like to know if someone asked you this question?

Absolutely right. You would ask: "What kind of car are we talking about?"

Therefore, in the question: "How many loops can be connected to the underfloor heating collector?", You need to take into account the diameter of the collector and how much of the coolant the mixing unit is able to pass through itself per unit of time (it is usually considered m 3 / hour). Or, which is also equivalent, what kind of heat load is capable of carrying the mixing unit of your choice?

How to find out? Very simple.

For clarity, we will show with an example.

Suppose you have a Valtec Combimix as your mixing unit. What heat load is it designed for? We take his passport. See passport clipping.

What do we see?

Its maximum flow rate is 2.38 m 3 / hour. If we install a Grundfos UPS 25 60 pump, then at the third speed at this ratio this unit is able to "drag" a load of 17000 W or 17 kW.

What does this mean in practice? How many circuits is 17 kW?

Let's imagine that we have a house in which there are some (unknown) rooms of 12 m 2 of usable floor heating area in each room. Our pipes are laid with a step of 20 cm, which leads to the length of each circuit, taking into account the length of the pipes from the warmest floor to the collector, 86 m.In accordance with the design calculations, we also obtained that the heat removal from each m2 of this warm floor gives 80 W , which leads us, respectively, to the heat load of each circuit

12 * 80 = 960 watts

How many rooms or similar circuits can our mixing unit provide with heat?

17,000 / 960 \u003d 17.7 similar circuits or rooms.

But this is the maximum!

In practice, in most cases, it is not necessary to rely on maximum performance. Therefore, we will focus on the number 15.

Valtec itself has a manifold with a maximum number of outputs - 12 to this node.

10. Do I need to make several contours of underfloor heating in large rooms?

In large rooms, the underfloor heating structure should be divided into smaller areas and several contours should be made.

This need arises for at least two reasons:

limiting the length of the circuit pipe is necessary in order not to obtain the effect of a "locked loop", in which there will be no circulation of the coolant through it;

correct operation of the cement filler plate itself, the area of \u200b\u200bwhich should not exceed 30 m 2. FROMthe ratio of the lengths of its sides should be 1/2 and the length of one of the edges should not exceed 8 m.

11. How do I know how many underfloor heating circuits are needed for my home?

In order to understand how many loops of underfloor heating will be needed and, on the basis of this, choose a suitable collector with the same number of outputs, you need to start from the area of \u200b\u200bthe premises themselves in which this system is planned.

After that, you calculate the usable floor area. How to do this is described in question 12 " How to calculate the usable floor area?".

Then, use the following method: starting from the step of the warm floor, break the usable area of \u200b\u200bthe warm floor in each room into the following dimensions:

step 15 cm - no more than 12 m 2;
step 20 cm - no more than 16 m 2;
step 25 cm - no more than 20 m 2;
step 30 cm - no more than 24 m 2.

If the floor area in the room is less than the specified dimensions, then it does not need to be broken.
We recommend reducing these values \u200b\u200bby 2 m 2 if the length of the pipe connection from the underfloor heating to the collector exceeds 15 m.
When dividing the usable floor area in the premises, try also to achieve that the length of the pipes in these circuits is either the same, or the difference between the individual circuits does not exceed 30 - 40%.How to find out the length of the pipes in each circuit, read in question 6 " How to calculate pipe length?".

Step back 30 cm from each of the walls of the room. Shade the resulting space. Mark on the plan the areas where the furniture will constantly stand: refrigerator, furniture wall, sofa, large wardrobe, etc. Shade these areas as well. The unshaded part of the floor plan will be the usable floor heating area that you are looking for.

For clarity, let's calculate the usable area of \u200b\u200bthe dining room, where the heated floor will be. The total area of \u200b\u200bthe dining room is 20 m 2, the length of the walls is 4 m and 5 m, respectively. The kitchen will have a kitchen set, a refrigerator and a sofa, which we will mark on the plan. Let's not forget to step back from the walls by 30 cm. Shade the occupied areas. See drawing.

Now let's calculate the useful area of \u200b\u200bthe warm floor.

13. What is the total thickness of the underfloor heating cake?

It all depends on the thickness of the insulation, since the rest of the values \u200b\u200bare known.

With the following insulation thickness, you will get the following values \u200b\u200b(the thickness of the finishing coating is not taken into account):

3 cm - 9.5 cm;
8 cm - 14.5 cm;
9 cm - 15.5 cm.

14. What do you use to calculate the water floor heating system?

To calculate both radiator heating systems and underfloor heating systems, we use the company's Audytor CO program.

Below we post a screenshot of the module of this program for the preliminary calculation of the warm floor and a screenshot of the module for the calculation of the layers of the warm floor pie.

Upon closer examination of these screenshots, you can understand how serious the correct calculation of the warm floor is.

You can also see the operation of the program itself, which makes it possible to carry out visual control over such important parameters as pipe length, pressure loss, temperature on the floor surface, heat that goes down uselessly, useful heat flow, etc.

15. How to determine the dimensions of the manifold cabinet in order to accommodate all the necessary units in it?

It is not difficult to determine the dimensions of the manifold cabinet. We again suggest using Valtec products and their ready-made recommendations presented in the table, provided that you use ready-made units for underfloor heating produced by this manufacturer.

Linear dimensions of the manifold cabinet

(ШРН - external; ШРВ - internal)

Model	Length, mm	Depth mm	Height, mm
SHRV1	670	125	494
SHRV2	670	125	594
ShRV3	670	125	744
SHRV4	670	125	894
SHRV5	670	125	1044
SHRV6	670	125	1150
SHRV7	670	125	1344
SHRN1	651	120	453
SHRN2	651	120	553
SHRN3	651	120	703
SHRN4	651	120	853
SHRN5	651	120	1003
SHRN7	658	121	1309

Selection of a manifold cabinet

Collector groups 1 (VT.594, VT59)	Cabinet model SHRN / SHRV + Combimix + ball valve	Cabinet model SHRN / SHRV + Dualmix + ball valve	Cabinet model ShRN / ShRV + crane
Collector 1 * 3out	SHRN3 / SHRV3	ShRN4 / ShRV4	SHRN1 / SHRV1
Collector 1 * 4out	SHRN3 / SHRV3	ShRN4 / ShRV4	SHRN2 / SHRV2
Collector 1 * 5out	ShRN4 / ShRV3	SHRN5 / SHRV4	SHRN2 / SHRV2
Collector 1 * 6out	ShRN4 / ShRV4	SHRN5 / SHRV5	SHRN3 / SHRV3
Collector 1 * 7out	ShRN4 / ShRV4	SHRN5 / SHRV5	SHRN3 / SHRV3
Collector 1 * 8out	SHRN5 / SHRV4	SHRN6 / SHRV5	SHRN3 / SHRV3
Collector 1 * 9out	SHRN5 / SHRV5	SHRN6 / SHRV6	ShRN4 / ShRV4
Collector 1 * 10out	SHRN5 / SHRV5	SHRN6 / SHRV6	ShRN4 / ShRV4
Collector 1 * 11out	SHRN6 / SHRV5	SHRN7 / SHRV6	ShRN4 / ShRV4
Collector 1 * 12out	SHRN6 / SHRV6	SHRN7 / SHRV7	SHRN5 / SHRV5

16. At what height should the manifold cabinet be installed?

There are no specific rules on this, but there are recommendations.

On the one hand, it is clear that when assembling the manifold cabinet, you need to take into account the height of the future screed and finish, so that a situation does not turn out when it will not even be possible to open the cabinet door.

On the other hand, it is necessary to take into account ease of maintenance and the need for possible replacement of individual elements of the system with the possibility of disconnecting the pipeline.

The shorter the pipe section, the greater its rigidity and vice versa.

Considering this factor, it is possible to raise the collector cabinet by 20 - 25 cm from the level of the clean floor.

However, one must not forget about a very important design element. If lifting the cabinet leads to an unacceptable violation of the design and it is impossible to solve this problem in another way, lower the cabinet to the floor level, but so that it can be opened.