To ensure that the floor provides the desired heating, adjustment of the distribution node is carried out. The adjustment is realized by 2 parameters:
The first one is set in the three-way valve. This is done manually, setting the desired temperature by turning the knob. Also in the scheme involves the thermostatic head, sensor, capillary tube. It is on the tube to set the temperature. The sensor is installed on the manifold.
By turning the cap on the valve it is necessary to achieve a given flow rate of the heating medium. If the flow rate is not known, it is recommended to adjust a few days, guided by the feeling.
Automatic adjustment consists of mounting servo actuators that interact remotely with thermostats. This way the comb and the pump will deliver as much water to the pipes as needed.
Underfloor heating manifold
Underfloor heating is considered one of the most effective ways in terms of energy savings and uniform heat distribution. As you know, heating is carried out by pipes with heat transfer fluid laid in the screed. Each room is a separate, closed circuit, or even several. Control their work produces a common node. a pipe rack for underfloor heating. Information on how this unit functions, the nuances of its assembly and regulation is offered to your attention in this article.
Adjusting the temperature of the water underfloor heating separately by room
If you only plan to make heating in the house with water underfloor heating, you can arrange separate temperature control in the rooms.
For this purpose, the laying of the floor heating circuits should be designed zoned. Т.е. The water floor heating pipe should only be laid in one room. If the area of a room is more than 12 sq. м. You should lay two or three loops of pipe.
In this case, the mixing node will be common, the temperature of the coolant will also be regulated for the entire collector simultaneously. Т.е. in the entire underfloor heating system, the temperature will be set by the supply unit and will not vary.
How to make a water underfloor heating control with multiple circuits? For this we will need to buy “normally open” actuators (desirable, but not obligatory). One for each circuit that we are going to control.
Install a temperature sensor (thermostat) in each room. Both wired and wireless options are available. Functionality can also be different. From simple mechanical on/off./off. Up to sophisticated temperature control by time of day and night. Cost will vary.
Wired room-by-room temperature control
If temperature sensors are wired, you will need to lay three wires from them to the collector. In this case the control will go directly to the actuator and no additional controller is required.
Wireless TP temperature control
If the temperature sensors are wireless, no further communication is required. This solution is practical if the repair is completed, and you want to control the temperature of the water underfloor heating at the end of the repair.
In this case, the automation will be located in close proximity to the temperature control unit and actuate the servo drives. And the sensors will only send the on and/or off signal to the automation controller. And the controller will in turn apply or remove voltage from the drive.
What regulates the bypass mixing node TIM JH-1036.
The mixing unit has a conditional mixing chamber, through which the underfloor heating circuit and the boiler heating circuit pass.
Typically, the floor heating mixing unit has one control parameter. the temperature of the water in the floor heating circuit. Mixing unit TIM JH-1036 has another bypass, and even with the ability to adjust. And it is not the bypass balancing bypass that is triggered by the excess head developed by the pump.
Pressure balancing bypass can be seen in the photo. the rightmost reason.
I need it because it is possible to overlap all directions of underfloor heating as a result of automatic regulation. By the way, how to adjust the balancing bypass TIM M307-4 I have not figured out. can anyone suggest.
As for the mixing chamber bypass, you can find this graphic explanation of the mixing chamber bypass operation:
over, it is not clear what the numbers on the scale mean and to what the current value is referenced. All this can only be found out by holding the mixing unit TIM JH-1036 in your hands:
It turns out that the adjusting screw is turning the cylinder, which has a slot that overlaps when turned. Through this slot, the water can be pumped by the circulation pump, bypassing the conditional mixing chamber.
Note that a sticker with a scale of 0 to 5 can be put on arbitrarily.
The maximum opening of the slot (in the photo above) corresponds to setting the adjusting screw to position 5 (in the photo below).
The technological step on the mixing chamber housing can be taken as a reference point for reading the scale value. At a scale value of 0, the slot is closed as much as possible. In this position, all water pumped by the circulating pump through the circuits of the floor heating passes through the mixing chamber.
When the bypass is fully closed, the heat output of the mixing unit from the heating system is at its maximum.
If the bypass is fully open, then part of the water circulates through the heating circuits without entering the mixing chamber. and the heat extraction power is minimal.
But in practice it turns out that it is not only the heat output that is regulated by the bypass.
Practical tips for adjusting underfloor heating systems
Installation of underfloor heating system is undoubtedly a responsible operation, but how comfortable it will be to use the finished heating system, most often depends on the competent adjustment. Setting up an underfloor heating system is not as complicated as it may seem at first glance.
Generally speaking, setting up a heating system consists of three steps. This balancing of underfloor heating loops, tuning of pump-mix unit and tuning of controller if there is one.
This article will describe the methods used to balance underfloor heating loops. First of all, it is worth noting the main misconceptions that occur in this kind of balancing.
- Sometimes you may hear that it is possible to balance the system correctly only by calculation, i.e.е., After calculating the resistance of all loops, calculating the adjustment position of control valves, set it on the manifold. Of course, a project with a competent hydraulic calculation speeds up the adjustment process and protects against installation errors. But, nevertheless, the underfloor heating system can be adjusted without theoretical calculations, although it will take more time.
- It is also a misconception that the water flow rates in all loops must be the same. In fact, the flow rate primarily depends on the heat capacity that each particular loop transmits to the room.
- You often hear that underfloor heating system does not need to be balanced, and the water consumption balances itself due to the thermostats, controllers and other automation elements. This statement is also not true. The point is that sooner or later there will come a moment when all the loops of the floor heating will open to the maximum, and the distribution of the heating medium must be such that all the water does not go into one loop, but is evenly distributed throughout the whole heated circuit.
So, the heating system is filled and tested, the boiler is started, the allen key is in the hand, giving a pleasant heaviness that turns into an itch of impatience. Where to begin?
First of all it is worth to define the goals and objectives of balancing.
The balancing task is not to set the required flow rate in each loop, but to set the flow rate ratio in the loops or the flow rate balance. The final costs are set during the adjustment of the pump and mixing unit. By changing the total flow rate through the manifold, the flow rate ratio through the loops is maintained.
The balancing is also different depending on whether the manifold unit has flow meters. VTc manifold blocks.596 (fig. 1), VTc.589 (Figure. 2), VTc.586 (Fig. 3) are equipped with flow meters that speed up the balancing procedure considerably and make it possible to carry out this operation without turning on the boiler, since they indicate in real time the water flow in each direction.
The flow rates must be distributed in such a way that the ratio between the loop lengths and the ratio between the required thermal loads are the same. For this it is desirable to know the required thermal loads on the loops. But even if the required loads are not known, it is possible to set the costs in proportion to the loop lengths. As a rule, this approach does not give much error, because loops with longer lengths also have higher capacities.
The balancing begins by selecting the longest loop (or the loop with the highest power, if known). The control valve on this loop opens to the maximum position, and the flow rates of all other loops will be set relative to it.
Let’s take the manifold with four loops as an example. Let’s assume that the loop lengths are as follows: 100, 75, 75 and 50 m.
In this case the adjustment starts with the first loop, which is 100 m long. It opens at maximum. Let’s assume that when the valve is fully open, the flow rate on this loop has settled at 4 l/min.
The water flow rate on the second and third loop must be: (75/100) 4 = 3 l/min.
The water flow rate on the fourth loop must be: (50/100) 4 = 2 l/min (Fig. 4).
It may happen that if you set the third loop, the flow rate will be 2.5 l/min even if the valve is fully open and will not reach the 3 l/min level. This means that the loop has more hydraulic resistance than the second loop of the same length (more branches, gimbals, supply sections). Balancing in this case is only possible with the boiler switched on and with at least a minimum heat transfer into the room. the first loop to (100/75) 2.5 = 3.3 l/min, the second loop to 2.5 l/min and the fourth loop to. (50/75) 2.5 = 1.6 l/min (Fig. 5).
After all the flow rates have been established, the loop balancing can be considered completed and the pump/mixing unit can be set up.
If you tune manifold blocks without flow meters, such as VTc.588 (figure. 6) or VTc.594 (fig. 7), it is only indirectly possible to judge the flow rates in the loops.
In this case, balancing can be done only with the boiler switched on and with at least a minimum heat extraction into the room. Preferably, the outside temperature must be lower than 5 ºC. The room must be kept clear of open windows and any large heat patterns (a working fireplace, etc).). Adjustment, as in the previous case, begins by determining the longest loop.
Then the system should be left to warm up for a few hours until the temperature in the loops has stabilized, after which the correct setting should be evaluated.
The correct setting is determined in one of the following ways:
- using the temperature of the water in the return pipe;
- according to the average floor temperature.
Determining the correct setting from the return water temperature
Heat flow rate, capacity and temperature difference between supply and return pipe are interrelated. If you reduce the flow rate of the loop, the temperature differential will inevitably increase. It is by this relationship that the correct setting can be determined.
If all loops have the same temperature difference between the supply and return pipes, it will mean that in all loops the water flow rate corresponds to the current capacity. And since the temperature in the supply manifold is the same for all loops, you can only equalize the temperatures before the return manifold.
It is most convenient to evaluate the temperature using a special thermometer such as the VT.4615 (Figure. 8). This thermometer is inserted between the pipe and the return collector through the “eurocone” connection (Fig. 9).
The reference temperature on the longest loop is determined, then all other valves are adjusted according to the deviations from this temperature. If the temperature in the loop is lower than the reference temperature, it means that the flow in this loop is also low and the valve must be opened a little. If, on the contrary, the flow rate is higher, the valve should be closed. Then after half an hour this operation should be repeated until the water temperatures before the return manifold are equal for all loops.
Determining the correct setting from the average floor temperature
The previous method is simple enough, but does not take into account the floor finish. If the rooms have different floor coverings, it is necessary for the loop costs to take this factor into account in order for the floor surface temperatures in these rooms to be felt as the same.
You can take into account the finish by measuring the temperature of the floor surface in different rooms and adjusting the water flow rates in different directions, so that the average floor surface temperature in the different rooms is the same. You can measure the temperature of the floor in different ways: with contact thermometers and pyrometers (Fig. 10).
Carry out the adjustment of the valves in the same way as in the previous case. A valve serving a loop, the floor above which has a higher temperature than the rest of the rooms, is closed, and vice versa. the valve opens when the floor temperature is low.
It is worth noting that the floor temperature should be measured in at least six points: above the pipes, between them, at the beginning of the loop, in the middle and at the end of the loop, and take the average value.
When the temperature of the floor surface in all rooms is close to this value, the setting up can be considered finished.
In order to protect valve setting from unauthorized interference, on VTc manifolds.594, VTc.588 has a mechanism for fixing the adjusted position. To fix the setting, the fixing screw must be screwed all the way in (fig. 11, 12). The screw is inside the hexagon. This screw limits the opening of the valve at the current level and prevents it from opening more. However, it allows you to close the valve completely. This allows all locking screws to be tightened fully after adjustment and the individual loops can then be locked with the same valve. In order to re-set the loop, simply open the valve as far as it will go.
As you can see, adjusting loops is a fairly simple operation, especially if you use handy equipment to do it. Setting up a pump and mixer unit (NSU) does not raise any questions for most installers either. Some of the features of the NSU setting will be discussed in a separate article.
Principle of operation and installation of the underfloor heating manifold
In the arrangement of warm flooring, many people give preference to special distribution mechanisms. combs for underfloor heating. With their help, you can improve the efficiency of such heating equipment, as well as achieve better performance. With such a device, the heating of the floor area will be maximum, and the energy costs. almost imperceptible.
Before you begin to understand the design of the comb for floor heating, the principle of operation and other features of the mechanism, it is necessary to understand what it is designed for and what its advantages are. The node ensures the balanced operation of heating systems in flooring, distributing the heat potential evenly over the entire area.
As the coolant is often used conventional liquid, which comes from a boiler or central line to a special node, where it is mixed with the liquid. Water begins to move in the circuits, which are under the floors.
The underfloor heating system has a complex circuit, which consists of several circuits and different lengths of pipes. It needs to receive a different volume of water, which forces the installation of special distribution elements. If the liquid enters the boiler without distribution, then a large part of it will be in the smallest circuit. This phenomenon will cause intense overheating, with long loops of heat will be significantly lacking.
Proper arrangement of the comb for underfloor heating with your own hands. is the best way to achieve the optimal flow of water in a particular area, taking into account the needs of the system in the heating medium. This approach allows for uniform heating of a small bathroom, and a large living room or bedroom.
In addition, the comb for warm floors is able to reduce the temperature of the coolant to certain indicators (the fluid from the boiler and the central pipeline is subjected to a temperature of 70-80 degrees Celsius, which negatively affects the consumption of fuel). As a result, there is a natural need to cool the coolant, for which such a node as a comb is used. Inside the mechanism are special sensors and valves that maintain the temperature regime at a certain level, which is set by the consumer.
It is not difficult to understand the constructional features of combs. Even an inexperienced shopper without professional skills will be able to understand the construction of such a unit and how to use it. So, among the constituent elements of the comb stand out:
Setting the distribution of floor heating
- Supply manifold.
- Return header.
- Fixing elements for mounting and assembly.
- Shut-off valves.
- Drain valve.
- A device that drains the system air.
- Valve supply in the heating coil.
If we consider each part separately, special attention should be paid to the supply manifold. It is a horizontal tube with two or more branches, as well as special flow meters at certain loads.
The “return” manifold has the same external characteristics, because it is also made in the form of a pipe with branches. However, the principle of operation and the task of this mechanism is very different. Instead of flow meters, a thermostatic valve, or “thermostatic head” is installed in the device. The detail regulates the temperature in different areas of the underfloor heating system.
Two collectors are fixed with mounting brackets. As for the shut-off valve, it completely blocks the supply and “return” lines, which are directed to the comb from the boiler or centralized line.
The task of the thermometer is obvious and is to monitor the temperature conditions in the manifold system. Drain cocks discharge water for repair work or basic maintenance of the system. And the Mayevsky valve, a device for bleeding air, prevents an unforeseen decrease in the efficiency of heating.
The pumping equipment ensures the correct movement of the coolant through the system, which is necessary for maximum efficiency. In addition, the valves can be equipped with additional elements, including fittings, angles, tees and other connections.
To keep the temperature level in the system constant, a certain amount of hot water from the boiler or mains is added to the flowing thermal fluid. For this purpose, a 2- to 3-way supply valve is installed in the node.
Two-way valves are fixed directly in front of the comb. In addition, they have remote temperature sensors installed near the “return” manifold. The mechanism may remain in two states. “closed” and “open. They are changed by changing the position of the stem.
The principle of operation of the unit is simple enough. When the system is started the 2-way valve opens and the heating medium from the installation flows into the branch pipe. The cooled down water from the return flow valve is then fed into the supply header. During this time the temperature will be measured by a remote sensor. If the fluid has already warmed up to a certain mode, the valve will close and further flow of the coolant will be halted. The circulation process continues.
After some time, the temperature of the liquid decreases and falls below normal. Then the thermostatic head of the valve will start to lift the stem, and the warmest water will flow to the heating medium in the comb.
By design the 2-way valve is a complex, but reliable system, which is almost impervious to mechanical damage. It is made of high quality, temperature-resistant materials, so there is virtually no chance of water penetrating under the floor covering. But in terms of accuracy and smoothness of adjustment, these products are slightly worse than 3-way valves.
Trying to perform an installation circuit comb with his hands, we can not but consider the principle of three-way valve. Unlike the previous element, it ensures more coordinated operation, i.e. к. consists of three rather than two inlets. One node receives the coolant from the boiler, the second from the outgoing collector, and a line from the “return” collector is connected to the third. Such a valve is easy to connect to the underfloor heating. The principle of operation of the system can be broken down into the following steps:
- 1. At the beginning of work in the three-way valve is closed the mixing line, while the supply of coolant from the boiler remains open. The heated fluid begins to flow into the comb.
- 2. A sensor located in the comb notifies of an excess in temperature, which causes the shut-off mechanism in the valve to move and the mixing line to open. The supply line is closed and the hot fluid is filled with the cooled fluid from the return line. If the temperature exceeds the allowable standard, the supply from the boiler will be suspended.
- 3. In the next stage, the temperature of the coolant will begin to come back to normal, while the stopper element will not change its location.
- 4. After several cycles of fluid movement the temperature of the fluid drops markedly. The phenomenon will be detected by the valve and the shut-off unit will close the mixing line.
The operating principle employed in such a valve ensures the smooth and precise regulation of the temperature. It also allows you to most effectively “prepare” the coolant for the underfloor heating system with a size of up to 150 square meters. Despite the advantages of the three-way valve, it has significant disadvantages. One of them is insufficiently high reliability.
After understanding the principle of operation, the scheme and features of installation of the comb, you can proceed directly to the selection of this design. In order not to make a mistake and make the right decision, you need to consider these parameters:
- Manifold material.
- Number of circuits, maximum pressure and fluid flow.
- Is there support for full automation, how many sensors to measure performance indicators installed, are there thermostats or electronic devices that allow more fine-tuning.
- Company manufacturer.
The comb models available on the market are based on a wide variety of materials. One of the most popular is brass. It is characterized by the highest strength and durability, but it does not come cheap. In the production of such a construction the casting method is used.
Stainless steel products, which are welded together, are also in particular demand. In terms of strength they are almost as strong as the previous type, but have a significant drawback. the inability to cope with the effects of corrosive processes.
Following simple tips, you can choose a reliable and quality comb, which will make the heating of the flooring as productive as possible. In this case, the connection of the underfloor heating comb will take very little time.
The temperature difference between the flow and return of the underfloor heating
At installation of a floor system it is very important to observe all technology of installation. This directly affects the comfortable temperature of the water underfloor heating. Make a mistake and do something wrong, and goodbye comfort at best. In the worst. goodbye to a working heating system. Therefore talk to you about how to avoid this and how to achieve a comfortable temperature in the house and underfoot.
Manual adjustment of manifolds TP
The easiest, albeit time-consuming way to adjust the temperature of the floor heating using manual valves. The task is somewhat simplified by the installation of flow meters (rotameters) on the comb.
Flow meters simplify the dosage of the amount of circulating coolant (flow rate) in one single loop of the underfloor heating system. In case of manifold temperature control, the flowmeter can also be used for flow balancing (leveling out differences in flow resistance) for loops of different lengths.
The main elements of the flowmeter valve, are:
- body with shut-off and control valve. It is screwed into the appropriate technical opening of the manifold;
- the bulb is made of transparent plastic or glass with a printed scale;
- Float indicator, which allows you to visually control the flow rate through the flowmeter.
Manually adjust the floor heating manifold by screwing/unscrewing the manual valves or by adjusting the flow capacity of the flow meters.
Important! Improvement of the efficiency of the floor heating system, as a result of its manual setting, will be noticeable only in the case of intensive circulation of the coolant through it. This can only be achieved by using a separate heat pump.
Sequence of manual adjustment of the underfloor heating temperature
At the beginning of the adjustment operations it must be ensured that the pipelines of the primary circuit are completely filled with thermal fluid and have no air s. They are filled following the main heating system (primary circuit). At this time, all locking and regulating valves on the manifolds must be closed.
After opening the primary and return cocks of the floor heating distributors, sequentially open the shut-off devices on each of the loops. Air bleeding is carried out through the Mayevsky cocks or automatic air bleeders of the combs. It is advisable to fill the next branch only after the previous one is completely filled and guaranteed to be de-blown.
After completing the first loop fill it is necessary to turn on the heat pump of the secondary heating loop and run the coolant through its system. The efficiency of fluid circulation is checked with built-in or clamp-on thermometers. As a last resort, you can simply put your hands on the supply and return pipes at the same time. they should be warm, but with a slight difference in heat.
Filled the first loop, should be cut off at both ends from the manifolds, using local shut-off and control valves. Then proceed with next loop.
After all loops of the TP are successively filled, their shutoff devices are opened and the heat pump is switched into operation. The temperature of the underfloor heating is adjusted through the supply of the heating medium to each of its branches. This is adjusted by changing the flow rate (valve or flowmeter) and controlled by the temperature gradient between the flow and return flow. Ultimately, this difference for the various circuits should be the same, within the range of 5-15 0 C. The longer the loop, the more the coolant will cool down and the higher the flow rate is required.
Important! Heat transfer in the floor water heating systems is carried out with a large inertia. Delayed heating of the floor surface is especially noticeable if the pipes are laid in a too thick concrete slab (over 60-70 mm). Sometimes the effect of changing the intensity of the coolant becomes noticeable only after several hours.
To control the correctness of the regulation of a hot water floor it is rational to use non-contact laser or contact electrical thermometers. Their installation to measure the temperature of the flow and return pipes will help reduce the time of obtaining the result of changing the settings from several hours to 10-15 minutes.
As a rule, the modern scheme of “underfloor heating” is quite complex, represented by several circuits with different lengths of pipes and the amount of heat carrier, so the role of such a node as a comb should not be underestimated.
With two-way valve
The main difference of the standard two-way valve circuit is the continuous water supply from the return without using a special shut-off valve. In this case, the mixing unit for the floor heating system performs periodic mixing of boiling water when the heat carrier cools down below the set parameters. This type of circuit is well-proven in practice, but only if the size of the circuits is not excessive.
- 1. Two-way supply valve;
- 2. circulation pumping equipment;
- 3. temperature sensor;
- 4. balancing type valve device;
- 5. check valve.
The valve device of the feeder type is characterized by a built-in liquid sensor-thermostat which cuts off or adds a certain amount of hot thermal fluid as needed. The stable temperature conditions on the perimeter of the valve ensure the highest possible service life. The benefits of this option are represented by smoothing out sudden spikes in the low capacity of the valve device.
With a three-way valve
Modern and highly effective mixing sets in underfloor heating systems with three-way valve technology are categorized as universal products. This design assumes mixing of the boiling water with the “return” directly inside the casing, as well as the combined function of the supply and bypass-type balancing valve. The damper, which has an adjustable position, is built into the faucet.
This type of control valves is equipped with special weather controllers, thermostats and servo drives, so it is the best option for installation in multiple circuits for heating very large rooms.
The main disadvantage of constructions with three-way valve is the possibility of hot thermal carrier inlet and the risk of excessive pressure inside the system that negatively affects the pipes and markedly reduces their service life. At the same time, the difficulty to regulate the temperature indicators as precisely as possible due to the high flow rate, so even a slight turn of the damper can cause a noticeable change in the temperature inside the floor heating system by 3-5˚C.
Special thermostats are used to control underfloor heating systems. About what it is and how to choose a thermostat for your needs, we will tell in the article: https://pol-master.com/tepliy-pol/termoregulyator-dlya-teplogo-pola.html.