In an autonomous heating system, a situation is often observed when radiators remote from the boiler give off less heat than those installed closer. The problem may lie not only in the long length of the highway, but also in an incorrectly drawn up scheme with a single contour. Is it possible to make several of them and what are heating circuits, their description and balancing?
Heating circuit balancing problems
The simplest example of the competent distribution of the coolant among several consumers is the heating of a multi-storey building. If a single-circuit scheme was used during its creation, some consumers would be left without heat. Therefore, the building has several heating circuits. The same principle can be applied to the autonomous system of a private house or cottage.
But first you need to figure out what a heating circuit is. Imagine that branching occurs in a certain section of the pipeline, and part of the coolant is directed along a separate circuit to another room. In this case, the length of each of the contours can be different, since the rooms in the house have unequal areas. As a result, water with varying degrees of cooling enters the common return pipe. But the big problem is the uneven distribution of heat in the house. To eliminate this, balancing of the heating circuits is necessary.
This set of measures aimed at uniform distribution of the coolant, depending on the length of each branch of the heating system. This can be foreseen even at the design stage:
- If the system has two heating circuits - their length should be approximately equal. For this, pipelines are divided according to the areas of each room;
- Installation of distribution manifolds... Their advantages lie in the possibility of using special elements that automatically restrict the flow of the coolant. The defining indicator is the length of the heating circuit;
- Application of special devicesregulating the amount of hot water depending on the set values.
The result of the measures taken to balance the heating circuits should be a uniform temperature in all rooms of the house.
Calculation of balancing heating circuits must be done at the design stage. It is not always possible to make modifications to an existing system.
Adjustment of the water heated floor
Most often, the problem of thermoregulation is encountered when designing a water-heated floor system. That is why, in his scheme, a collector is mandatory, which is responsible for this closed heating circuit.
Separate circuits are connected to each inlet and outlet. Their length may not always be the same. Therefore, the design provides for regulation mechanisms:
- Flow meter - installed on the collector return pipe. It performs the function of adjusting the quantity of water depending on the length of the heating circuit;
- Thermostats - limit the flow of water by temperature.
For the initially correct distribution of the coolant along a closed heating circuit, it is enough to make a simple calculation. The main indicator is the volume of each branch. The sum of these values will correspond to 100%.For the calculation, you need to divide the volume of each circuit and calculate the coefficient of limiting the flow of water into it.
When balancing a water-heated floor with a large area, it is recommended to take into account the number of turns in each circuit. They create additional hydraulic resistance.
Collector heating system
It is much more difficult to organize a uniform distribution of the coolant in a circuit consisting of two heating circuits. Until recently, conventional tee distributors were used for this. However, they could not provide the desired result - a larger volume of water passed along the path of least hydraulic resistance. As a result, there was a significant difference in temperature in the rooms.
Having found out what a heating circuit is using the example of warm water floors, the same model was transferred for the entire system of the house. Only in this case it became possible to make separate highways for each room or group of rooms. Most often, a two-circuit heating system is used, which, in comparison with the classic one, has the following advantages:
- The ability to adjust the flow rate of the heating agent in each branch using flow meters. Thus, the balancing of individual heating circuits is carried out without changing the parameters of the entire system;
- If necessary, you can completely exclude the heating of the premises. This may be necessary to save on current heating costs;
- The absence of a large influence of the length of the circuit in the heating on the temperature mode of operation. The main thing is to install the control equipment.
The disadvantage of this scheme is the large length of the highways. On average, 30-40% more consumables will be required to create collector heating than for the classic version. At the same time, the total amount of heat carrier increases, which increases the required power of the heating boiler.
It is not advisable to install collector heating for single-storey houses with an area of up to 120 m².
Balancing valve
But what to do if initially there is a ready-made heating system, and the above mechanisms for adjusting the circuits are absent? A balancing valve can then be installed in such closed heating circuits.
The closest analogue of a balancing valve is a conventional shut-off valve. But only in contrast to it, the valve mechanism provides for the possibility of automatic or manual adjustment of the coolant inflow into a specific heating circuit. For large systems, automatic models are chosen. If it is possible to carry out manual periodic adjustment, you can install a mechanical analogue.
The principle of its operation is to restrict the flow of the coolant into a separate line. For this, the design provides a rod that performs a shut-off function.
When choosing a specific model, you must pay attention to the following parameters of this equipment:
- Working medium pressure value - maximum and nominal;
- The difference in pressure in the return and supply pipes. This is important, since the excess coolant is redirected to the return line;
- The value of the water flow rate in pipes;
- The nominal temperature mode of the system.
These characteristics can be taken from a preliminary calculation of heating, or they can be obtained empirically by the method of simple calculations. The cost of a balancing valve directly depends on its functionality, pipe diameter and material of manufacture. Stainless steel models that work in automatic mode have proven themselves well.
Having learned what heating circuits are and methods for balancing them, you can optimize the performance of the entire system. But at the same time, it is important to monitor the pressure readings in each of them, so as not to create an excessive hydraulic head.
You can get acquainted with an example of balancing by watching the video:
