How to set up a Valtek manifold with flow meters for heated floors

What are manifolds for heated floors and why are they needed?

Water floor heating requires laying a large number of pipes. Since the pipes are used with a small diameter, they have high hydraulic resistance. So that the boiler can “push through” the heated floor and so that the floor is heated more or less evenly, the length of one pipe is limited. Theoretically, the maximum length of one circuit (pipe) is 120 meters. In practice, it is recommended to do no more than 70-90 meters. Even at 90 meters, until the water reaches the end of the pipe, it cools down significantly.

A Valtec manifold is needed to connect the circuits to the supply and return pipelines

So, there can be several such circuits even in one room. What if heating is done in several rooms? What if there are also several floors? There may be a dozen contours or even more. It all depends on the heating area. All these pipes cannot be connected directly to the boiler. This is why collectors are needed - to connect underfloor heating circuits. In the simplest version, the collector consists of two pipes - supply and return - with bends welded to them. The heated floor circuits are connected to these outlets. There may still be shut-off valves in place so that the water supply in a particular loop can be shut off.

Not Valtek, but one of the simplest collectors. Bends and shut-off valves only

But supplying and collecting coolant are not all the functions that a collector usually performs. The length of the circuits connected to the collector may vary significantly. If the collector is simply pipe branches, the shorter and longer ones receive the same amount of coolant. This results in the floor being too hot in some places and too cold in others. To be able to regulate the temperature (indirectly), flow meters or control valves are installed. They allow you to manually or automatically balance the flows so that the floor temperature in all zones is almost the same. With their help, you can make a specific area warmer. But not because it happened so, but because I want it that way.

Typical connection diagrams

Water heated floors are rarely used as the only source of heating. Heating only due to underfloor heating is permissible only in regions with a mild climate, or in rooms with a large area, where heat removal is not limited by furniture, interior items or the low thermal conductivity of the floor covering. Almost always it is necessary to combine radiator circuits, hot water preparation devices and underfloor heating loops in one heating system.

Typical diagram of a combined heating system with connection of radiators and underfloor heating circuits. This is the most technologically advanced and easily customizable option, but it also requires significant initial investment. 1 - heating boiler; 2 — safety group, circulation pump, expansion tank; 3 - manifold for separate two-pipe connection of radiators in a star configuration; 4 — heating radiators; 5 - underfloor heating manifold, includes: bypass, three-way valve, thermostatic head, circulation pump, combs for connecting underfloor heating circuits with gearboxes and flow meters; 6 - heated floor contours

There are quite a large number of variations in the design of the boiler room piping, and each individual case has its own principles of operation of the hydraulic system. However, if you do not take into account very specific options, then there are only five ways to coordinate the operation of heating devices of various types:

1. Parallel connection of the underfloor heating collector to the main line of the heating unit. The insertion point into the main line must be made up to the connection point of the radiator network; the coolant supply is provided by an additional circulation pump.
2. Association according to the type of primary and secondary rings. The line, wrapped in a ring, has several supply connections in the supply part; the coolant flow in the connected circuits decreases with distance from the heating source. Flow balancing is performed by selecting the pump supply and limiting the flow with regulators.
3. Connection to the extreme point of a coplanar manifold. The movement of the coolant in the heated floor loops is ensured by a common pump located in the generator part, while the system is balanced according to the principle of priority flow.
4. Connection through a hydraulic separator is optimal when there are a large number of heating devices, a significant difference in flow rates in the circuits and a significant length of underfloor heating loops. This option also uses a coplanar manifold, but the hydraulic arrow is necessary to eliminate the pressure drop that interferes with the correct operation of the circulation pumps.
5. Local parallel loop connection via unibox. This option is well suited for connecting a short-length heated floor loop, for example, if you need to heat the floor only in the bathroom.

The simplest option is to connect a heated floor circuit to a radiator heating system with a coolant temperature of 70-80 °C. 1 - line with supply and return of the high-temperature circuit; 2 - heated floor contour; 3 - unibox.

It must be remembered that the nature of the operation of a heated floor may also change depending on the installation pattern of the coil. The “snail” scheme is considered optimal, in which the tubes are laid in pairs, which means that the entire area is heated almost evenly. If the warm floor is arranged as a “snake” or “labyrinth”, then the formation of colder and warmer zones is practically guaranteed. This drawback can be eliminated, including through proper configuration.

Equipment and capabilities

Products are manufactured under the Valtec brand by an Italian company. They have been on the Russian market since 2003, so they know our realities first-hand. We produce a wide range of plumbing engineering fixtures and devices. And collectors for heated floors are among them.

general description

The Valtec underfloor heating manifold is made of brass or stainless steel. Or rather, most often, the body is made of stainless steel, and the “filling” is made of brass. In the catalog they are called a manifold block, since there are a couple of devices - for the supply and for the return pipeline. Complete kits are equipped with:

• there are flow meters on the feed comb;
• on the return pipeline there are manual shut-off valves.

Below is the supply and there are flow meters.
At the top there is a return pipeline, manual valves are installed. In this option, using flow meters, you can adjust the coolant flow in each of the loops, and manual valves on the return pipeline serve to block circulation. But this configuration can be automated. To do this, servo drives are installed on manual valves, which are connected to thermostats installed in the premises. In this way, a constant floor or air temperature can be maintained. Depends on where the heat sensors are installed, because the thermostat reacts to their readings.

An automatic air bleeder is also installed on the Valtec manifold. This is a device that allows you to remove air trapped in the coolant automatically.

Range

All collector blocks for Valtek underfloor heating can be divided into two groups: with and without adjusting flow meters. There are only three options in the first group and two in the second, but in each the number of connected taps is from two to twelve.

• With supply flow meters VTc.594.EMNX. Body - stainless steel AISI 304, fittings - brass CW617N, seals - EPDM 70Sh, number of outlets - from 2 to 12. Operating pressure 8 bar, nominal diameter of manifolds - 1 inch, outlets - 3/4″ external thread, connection - eurocone. Price - from 9 thousand rubles. (for 2 outputs), up to 25 thousand (for 12 outputs).
• VTc.589.EMNX. Manifold for propylene glycol systems. Body - AISI 304 stainless steel, brass fittings and EPDM 70Sh rubber seals. Working pressure 9 Bar, coolant temperature not higher than 90°C. The nominal diameter of the collectors is one inch, the outlets are 3/4 inch with a Eurocone.

  
  Compatibility table for various Valtec manifolds with components

• VTc.596.EMNX. Valtec brass manifold (CW617N brass) with nickel plated. EPDM 70Sh seals, fittings made of the same brass. Working pressure 10 Bar, outlet connection - Eurocone, diameter 3/4″. nominal collector diameter 1 inch, number of outlets from 3 to 12. Price from 12 thousand rubles. for 3 exits, up to 38 thousand rubles. for 12 exits;
• nominal collector diameter 1 and 1/4 inches, number of outlets from 4 to 12. Price from 9 thousand rubles. for 4 exits, up to 45 thousand rubles. for 12 exits.

The basic package includes manifold plugs, automatic air vents, drain valves (for filling or draining coolant), and brackets for installation.

How to balance system operating parameters?

Primary adjustment of underfloor heating circuits using flow meters involves the use of special balancing valves. This element helps equalize the pressure between the coolant circuits. Thermostatic valves allow for quick adjustment of parameters.

The balancing equipment is configured as follows:

• The lid is opened using a key with a diameter of 5 millimeters;
• the valve is tightened as much as possible;
• the specified number of revolutions is set in accordance with the preliminary calculation data;
• the ring for the stopper is tightened using a hex key, the diameter of which is 6 millimeters.

If you deviate from technology standards, you can damage the valve structure, which will lead to problems with the operation of the equipment.

Setting up manifolds with tuning flow meters

Preliminary adjustment of underfloor heating collectors is necessary and important. Even if the system has thermostats, controllers and other automation. If you entrust the adjustment to automation, after a while all flows will be as open as possible. So before starting the system, we are setting up the collector. Adjust the flow rate on a cold system without turning on the boiler. Heating is started after setting the flow rates in the loops - to check the temperature.

Valtec manifold with flow meters is easier to configure

What is a flow meter and its design

Flow meters are used for the initial setting of flows, which is easier, more accurate and faster. In addition, during operation they allow you to evaluate the current flow rate in relation to the one set during setup. To understand the mechanics of adjustment, you need to know how the flow meter is designed and how it works. It is a hollow body with a poppet valve, which is supported by a spring. The spring is calibrated. Its top is formed into a transparent cone with a scale.

How does the Valtek flow meter work?

In order to be able to navigate by the flow values ​​and, in fact, regulate it, a flow indicator is attached to the spring. For supply-mounted flowmeters, the default flow indicator is mounted on the top of the housing. In this position, it points to “0” and the flow is blocked (as in the photo above). If flowmeters are designed for installation on a return manifold, the flow indicator is located at the bottom.

There are two types of flow meters - with and without fixing the position of the adjusting sleeve. The first ones are more reliable, since the settings are not lost, which can happen with regular ones. But they are more expensive. And since the collector unit itself is not cheap, flow meters are often installed without fixation.

How to set the flow on a flow meter

The scale has marks and numbers from 0 to 5. The number indicates the strength of the flow - this is the speed of movement of the coolant in meters per second (m/s). The flow adjustment procedure is as follows:

• Remove (unscrew) the protective cap. On Valtec manifolds they are red.
• Loosen the fixing sleeve. If it is not there, skip this step.

  
  Aligning the flow meter with a fixing ring

• Scroll the adjusting sleeve until the flow indicator stops at zero.
• We turn it in the opposite direction, setting the required value.

  
  Aligning the flow meter without a lock

• If there is a fixing sleeve, tighten it until it stops.
• We put on the protective cover.

So, one by one we set the flow meters of each loop of the heated floor. As you understand, without the fixing sleeve there are slightly fewer steps. Please note: it is better not to skip the step with setting zero. This doesn't take much time, but allows you to check the calibration.

Method of adjusting floor heating flow meters

If you do everything according to the rules, you should have a thermal engineering calculation that indicates the flows in each loop. Do you have a plan? Then set the values ​​according to the plan. If not, we will act based on the size of the contours. Provided that pipes of the same cross-section are laid, it will be necessary to change the flow rate based on the required heat transfer. But in this case, it is necessary to know the length of the pipe in each loop.

Let's look at an example. Let us have four circuits: 90 m, two 75 m and 50 m. The procedure for adjusting the flow meters of the Valtek collector is as follows:

• On the longest loop, 90 m long, we open the flow meter completely (if maximum flow is needed) or set the value that is required. Let us assume that for this case the maximum flow rate is 5 m/s. To do this, lower the flow indicator to the very bottom. There is a sign there for 5 m/s.

  
  With the same length, the flows can be different. Depends on requirements (main heating or additional heating) or floor covering

  Read also:  How to choose a liquid for heated floors?
• Let's calculate the required flow rate for 75 meters. Determined by the length ratio: 75/90 = 0.83. We multiply the flow rate on the first loop (5 m/s) by the resulting figure. It turns out 5 m/s * 0.83 = 4.17 m/s. We set the flow indicator on two 75 m loops just below the 4 m/s mark.
• Using the same scheme, we calculate the flow rate for a 50-meter circuit: 50/90 = 0.55. We calculate the required coolant speed: 5 m/s * 0.55 = 3.7 m/s. We set the flow indicator slightly short of mark 4.

If the flow on the longest loop should be below the maximum possible, set it to the required value (at least 3 m/s, at least 2 m/s). We recalculate the rest using this flow value.

Next, turn on the boiler and check how correctly the collector is configured. With the same length and the same flow rate, it may turn out that one circuit heats much better. This is due to a different installation scheme. A circuit that heats less well most likely has more bends or they are steeper. This increases hydraulic resistance, which reduces the speed of coolant movement. This means less heat is transferred. The solution is to increase the flow rate a little and see the results.

Components

In total, the collector contains two pipes:

• one performs the functions of a mixer and supply of coolant to the circuits;
• the other serves to collect return flow from all circuits and return the water cooled in the circuits to the boiler, and, partially, through a two- or three-way valve, to the output mixer.

Hot water from the boiler is added to the mixer by turning on a thermostatic valve, which is placed in the path of water supply to the mixer. When the temperature in the mixer drops below the permissible level (we remember - this is 40°C), the valve supplies a portion of hot water.

Please note: a thermostat is installed at each outlet of the mixer comb to limit the volume of hot water for each heated floor circuit.

This group of bimetallic valves changes the flow area, as well as the volume of water passed through. This allows you to set the temperature as desired. Flow sensors are installed at the return inlets, and the return comb is also equipped with an air vent. The coolant is pumped through the system using a water pump, which creates the necessary pressure in the line.

A complete set of manifold parts also contains various plumbing fittings. In a set of devices for warm water floors, the collector is perhaps the most important of them, as it provides:

• safety and proper use of floors;
• the ability to configure comfortable conditions for using heating appliances.

Features of setting up a Valtec manifold without flow meters

If the manifold is not equipped with flow meters, but only with valves, you will have to set the flow rate by touch. This is not figurative, but literally. Knowing the length of each circuit, we open the flow to the maximum on the longest one. We screw the rest approximately. You can count the number of valve revolutions and focus on them.

Manifold for underfloor heating without flow meters

Next, we turn on the heating and wait until the floor warms up. If you have a thermometer, measure the floor temperature in the operating area of ​​each circuit. There is no thermometer - we feel and compare sensations. Based on the results, we adjust the position of the valves and wait again for several hours. We continue this way until we are satisfied with the result. In principle, a Valtec manifold with valves without a flow meter is not that difficult to configure.

Evaluating collector settings based on return temperature

This check is based on the fact that with a correctly adjusted flow rate, the return temperature on all circuits should be the same. To set up or check this type, you need special thermometers. They are installed on the return pipeline between the manifold inlet and the pipe.

You can adjust the collector using a return thermometer

The temperature of the longest circuit is taken as a reference - all the others are adjusted to it. Only the adjustment results will need to be corrected after a few hours. When the floor heated by adjustable circuits warms up or cools down (depending on the adjustment) and the temperature in the return pipe changes again. It will take several such adjustments until the difference becomes insignificant.

Results

It is important to ensure that when the water floor heating system is operating, the flow rate on the collector is visible. This is necessary for maintenance. Each water circuit must have its own flow meter.

We recommend: How to connect a mixing valve for underfloor heating?

As you can see, in the equipment, each element performs its own functions, so each one needs to be given sufficient attention, and in order for the entire system to work as one whole, it is worth equipping it with a flow meter and a collector, which will evenly distribute all the heat.

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Features of adjustment

For each individual room, the rotameters are adjusted separately. Control is carried out according to the diagram of the installed circuits. In this case, the level of heating of the liquid and pressure is taken into account.

It is recommended to carry out balancing according to the following instructions:

1. The total amount of coolant passing through the collector in one minute is determined. Indicators are taken in liters. The resulting value is taken as 100 percent.
2. The percentage flow rate of each individual water circuit is calculated. The result is converted to liters per minute.
3. The flow meter regulates the amount of liquid supplied to the pipeline.

Using these steps, you can perform long-term adjustments to the water circuit. To indicate the actual parameters, it is necessary to observe the flow meter readings. According to observations, it is possible to accurately determine the flow rate of the circuits connected to the collector.

Manifold with flow meters for heated floors

The flow meter is adjusted depending on the installed model. After connecting the device to the manifold, preliminary settings should be made by setting the initial position, which allows access to liquid.

In rotameters without a built-in valve, an additional locking device is used to set the “open” position. In this case, balancing is performed during the operation of the system.

Combination devices for metering coolant flow can be pre-set using full turns of the built-in valve. Each turn allows you to reduce the clearance by a set value.

Adjustment of the flow meter of the floor heating system is carried out taking into account the control of the fluid speed in one minute - from 0.5 to 5 liters.

Before setting up the rotameter, you should check the condition of the installed circuit. Trial testing is necessary to exclude the presence of leaks in the circuit, which could cause distortion of the indicators in the device.

The flow meter is an important element in a multi-circuit underfloor heating system. The device allows for a uniform flow of liquid into all individual pipelines. In order for heating equipment to function as efficiently as possible, you must select the right rotameter, as well as install and configure it in accordance with technical requirements.

Finally , the heating system of my house is assembled. The boiler is started. Let me remind you that I decided to heat my house only with heated floors. Although there are not many rooms in the house, in order for the comfort in all rooms to be the same, it is necessary to adjust the heated floor. We will talk about how to set up a heated floor in this article.

Setting up a heated floor is not as complicated as it might seem at first glance. Generally speaking, setting up a heated floor consists of three stages. First, balancing the underfloor heating loops, then setting up the pump and mixing unit, and finally setting up the controller if you decide to automate the heating system. I decided to fully automate the heating system in my house. Therefore, I purchased a controller, servos and temperature sensors. Let's look at the first stage of setup in detail, since the success of the entire setup depends on how well it is done.

Setting up a warm floor

And now, the heating system is filled and tested, the boiler is started. Everything is ready to set up the heating system.

Before you start setting up heating, you need to decide on its goals and objectives. The main task of balancing is not to establish the required flow rate in each loop, but to establish the ratio of flow rates across loops or flow balance. It is worth remembering that the final flow rate is set during setup of the pumping and mixing unit. By changing the total coolant flow through the collector, the ratio of flow through the loops will remain the same.

Setting up heated floors using flow meters

The presence of flow meters on the collector block has a significant effect on balancing. Flow meters significantly speed up balancing and allow it to be done without turning on the boiler. This is possible because the flow meter shows the coolant flow for each circuit in real time.

The distribution of coolant flows must be carried out in such a way that the ratio of flow rates along the loops and the ratio of the required thermal powers coincide. To achieve this, it is advisable to know the required thermal loads on the hinges. But even if this data is not available, you can set the costs in proportion to the lengths of the loops. In most cases, this approach does not produce a large error due to the fact that loops with large lengths also have greater powers.

Purpose of using the collector

A collector is a device with which the coolant flow is distributed over individual circuits of the water floor and then returned back for heating. The collector unit looks like two pipes with holes to which the system circuits are connected.

The presence of a distribution manifold in the heated floor arrangement makes it possible to control the volume of coolant flow. One of the collector pipes is the supply pipe; hot water flows into it and the inputs of the water floor circuits are connected to it.

The return circuits are connected to the return pipe of the collector. The openings to which this connection is made are usually equipped with threaded, fitting or other connections.

The collector consists of a number of elements such as the collector itself (1 and 2), an adapter for the Mayevsky tap (3); drain valve (4); air vent (5); valve (6); bracket (7); Eurocone (8)

Various devices are also installed here with which you can regulate the coolant flow rates. The simplest version of an industrial manifold is a pipe with a connector called a Eurocone. This is a completely convenient and reliable unit, but it does not allow you to control the flow of water.

To effectively use such a device, you will have to additionally purchase and install a number of elements.

The manifold made in the DPRK is a little more complicated. In addition to the connections at the outlets, valves are installed here; no automatic means of regulating the flow are provided. This is an excellent and inexpensive option for a water floor in a small area with two or three contours of the same length.

Such a system does not require complex management. But on large areas, this type of collector will have to be supplemented with automation.

In addition, the center-to-center distance between the feed and return sections of Chinese devices does not meet the standards adopted in Europe, which can cause problems when connecting it to European-made devices.

Ball valves in such devices are sensitive to low-quality water, and over time they begin to leak. To fix the problem, it is enough to replace the O-rings, but you must take into account the fact that the need for such repairs will arise periodically.

If the operation of the water floor system is intended to be automated, it makes sense to purchase at least a manifold with control valves.

Servo drives can be installed on such valves, connected to thermostats in the rooms. This will ensure automatic control of the coolant flow in accordance with data on the air temperature in a particular room.

To automate the operation of a water heated floor system, flow meters are installed on the collector supply (indicated by a frame), and connectors for servo drives are installed on the return (blue caps at the bottom)

It is most difficult to control a water floor system in which the individual circuits vary markedly in length, but in complex systems this is usually the case. In such a situation, the optimal choice would be a manifold with flow meters installed on the supply, and sockets intended for mounting servos on the return.

Using flow meters, it will be possible to adjust the intensity of the coolant flow, and servo drives in conjunction with thermostats allow you to set the appropriate temperature on each circuit.

If there is no need for automatic control, you can purchase a supply manifold with flow meters, and a return manifold with conventional valve taps.

It happens that it is not possible to choose a collector with the number of connection sockets that corresponds to the project. Then you can take the device “with a reserve”. And the extra holes are simply closed with plugs.

This solution may be useful if you later need to add a couple more loops to the water floor system.

Functionality and principle of operation of the flow meter

The main function of flow meters or, as they are also called, float rotameters in a heated floor system is to regulate the coolant flow in water circuits. Installing such a device allows you to:

• avoid excessive consumption of electrical energy in the process of heating the coolant,
• ensure uniform heating of all water circuits,
• eliminate temperature fluctuations in different rooms.

The need to use flow meters arises in buildings where floor coverings of different areas are heated. Large rooms require a longer pipeline length, so they heat up less intensely than small rooms. Therefore, it is possible to achieve uniform heating and ensure a comfortable temperature throughout the entire house only with such a device.

The flow meter for a floor heating system is a mechanical type device with a plastic or brass housing. Inside it is a float made of polypropylene. On the top of the body there is a transparent bulb with markings. During the circulation of the coolant, the float comes into action, moving up and down. According to its location, you can use a scale to determine the volume of liquid in the pipeline.