Independent heat supply scheme

Dependent and independent heat supply scheme: description, features

For most people, the term "independence" in The heating system plan is associated with dependence on electricity, and means that this is the kind of heating that can work quite normally even without an electrical supply.

In fact, these are two completely different concepts, so we propose to understand what a dependent and independent heat supply scheme is, as well as what advantages each of them has.

General information

Dependent system

Such concepts as "dependent" and "independent" can refer exclusively for centralized heating systems. This system is capable of serving several buildings at once, to which hot water or any other heat carrier is supplied through the main pipeline.

If the connection scheme is dependent, then the distribution internal system in the building will communicate with each other through the main pipeline, and the heat carrier from the main will begin to flow through a special unit called an elevator, and then it will reach the radiators.

Elevator is a mixing unit, and in it an extremely hot heat carrier from the mainline is mixed with the one that has had time to cool down "in processing", and as a result, water from normal temperature.

Independent system

But in an independent heating system according to the scheme, the distribution internal system of the building does not have a connection with the highway, it turns out that both systems are separated. Heat energy from the main heat carrier is transferred through internal channels through a heat exchanger. With its help, it turns out to heat cold water from the water supply system for the hot water supply system.

Differences between the two systems

So, let's compare all the advantages and disadvantages of each option.

A dependent heating system has two main advantages :

• Simplicity of the device.
• Low cost.

But there are still many disadvantages:

1. It is not possible to adjust the temperature of the heat carrier that enters the internal distribution system. Naturally, there is a special valve in front of the elevator, due to which it will be possible to limit the flow of the heated heat carrier from the main path, but it is simply not designed for such an adjustment, and when trying to reduce the volume of water that will enter the mixing unit, it will lead to the fact that the mode of operation will be violated, the circulation will worsen.
2. The internal distribution system in the building is powered by the main heat carrier, and, as a rule, it is not of the best quality.

   Moving along a large pipeline network, such an environment will collect huge amounts of scale, sand, rust, and often it also brings in large amounts of oxygen.These factors often lead to rapid wear on fittings, piping and radiators within the distribution system.

If we talk about an independent heat supply scheme, then things are a little different with it. Its disadvantage is cost, and even higher costs for repair work if necessary.

But there are also advantages:

• The amount of heat that enters the internal system can be regulated in the latitudinal limit, and this is done by heating at times more economical (saving money in comparison with the dependent type of heat supply scheme is from 10 to 45%).

• The internal system can be "charged" with a highly purified thermal medium, and the owners of the building will be able to select its chemical composition at their discretion, for example, use the same antifreeze.

Please note, that the larger the heated area of ​​the building, the more profitable it is to use an independent scheme, since saving thermal energy and increasing the life of elements on a large scale will help compensate costs for arranging the system.

At the moment it is possible to connect to the centralized heating system even by an independent method of heat supply.

Question details

Dependence on electricity

Information about the device of an independent and dependent heating system for ordinary users is usually only for informational and reference purposes, and for this reason, where centralized heating systems are used, namely in cities, designers and utility workers.

In the villages and other settlements where there are private houses, there is simply no centralized heating system.

The question of the energy dependence of the heating system is becoming more relevant, since in the private sector, where every house has an autonomous heating device, problems with the supply of electrical energy are far from uncommon, especially if the weather is bad outside. So let's see how you can create an individual heating that will not rely on electricity.

Solid fuel boilers

A solid fuel boiler is certainly considered independent. It does not need a centralized supply of fuel and electricity. In a house where there is such a unit, even with perfect isolation from the whole world, it will be warm if the owner of the building has enough firewood or corners (fuel).

But it should be borne in mind that everything that has been said will apply to those solid fuel boilers with a simple design, in which fuel will be placed manually after a time interval of 4 hours.Any modifications to it that have been created in order to minimize user involvement need to provide electrical power :

1. Pellet boiler - in this case granular fuel is used, called pellet, which is presented as pressed shavings, or cake. Granules are small and uniform in size, so they can be thrown into the combustion chamber using a screw feeder. Simply put, the user will only need to load a certain amount of fuel into the bunker, for example, for a couple of days, and then the boiler will operate in automatic mode all this time. In this case, electricity is only required to power the screw motor.

2. Pyrolysis boilers - the furnace in such a boiler is made in the form of two chambers, and in one of them the firewood is kept at a high temperature and limited air intake (which is also called primary). Under these conditions, the wood will emit a mixture of combustible gas (this process is called pyrolysis), which in turn enters the second combustion chamber and is burned there. To burn gas, a large amount of air is injected in the chamber, and this is already called secondary. In order to maintain an optimal operating mode, both the first and the second chambers should be supplied with air in a certain volume, and this is possible only when the fan is running. Such devices will naturally require electricity to operate.

3. Boiler with top combustion - this fits the definition of "independent heat supply scheme", but in this case, perhaps, it will be possible to find an exception, since certain models of boilers with combustion from above are considered volatile. The duration of work on one tab is possible due to the fact that the fuel will be stacked in the form of a column or tower, and then ignited from above.
4. Boilers with forced air addition - The furnace in such a boiler is usually single-chamber, but only slightly enlarged. The difference from a standard boiler here is that there is a fan and a gravitational damper in the blower, which, when the fan is idle, will lower under its own weight and block the access of air into the furnace.

A device with forced air supply operates according to the following scheme:

• While heating of the heat carrier is required, the fan operates and keeps open the damper, thereby forcing air into the firebox.

• When the thermal sensor gives a signal to the controller that the thermal medium has reached a certain temperature, it will immediately turn off the fan. The damper will fall, and the access of air to the furnace will be blocked, because of which the fire will go out.
• After the heat carrier has cooled down, the controller, on a signal from the thermal sensor, will turn on the fan again, and it will fan the fire in the furnace.

Please note, that without electricity such a boiler will not function, as it is needed for both the fan and the automatic system (thermal sensor + controller).

Gas boilers

And even a gas boiler can be volatile, since this model will work according to the following principle - the user lights one burner, which from the moment will burn constantly, and from time to time the main one will light up from it.

This automatic safety system is mechanical, namely in the sense that its action is based on a change in the volume of material due to a change in temperature.

The disadvantage of an energy-dependent gas boiler is that the pilot burner, although it seems small in appearance, consumes a fairly large amount of gas, and in this case, a volatile boiler will still be much more economical, in which has electronic ignition.

Which heat supply is better?

The use of an energy-dependent heating system is justified only in one case, namely, if during the operation of the electrical supply network there were frequent crashes were noticed.

If there is no such problem, but it is worth equipping an electricity-dependent system, since it is many times more practical. The fact is that not only the convenience of using a heat generator, but also the type of circulation of the heat carrier should be taken into account.

In a volatile system, circulation can be extremely natural, while the heat carrier will move through the pipes due to convection. In the variant that is considered volatile, the heat carrier is pumped through the pipes using a circular pump, and this gives a huge number of advantages :

• You can use pipes with a small diameter, and the slope is minimal.
• The contour can be of any desired / required length.
• The entire circuit is heated evenly, and with natural circulation, the radiators that are farthest from the boiler are relatively cold.
• Due to the high speed of movement, the heat carrier will not have time to cool down much inside the circuit, and therefore it is not necessary to operate the boiler at maximum power (only in gentle mode).

Results

When using a system that is considered volatile, it is possible to warm up the heat carrier not by 100%, which is often required in the off-season period (with the natural method of circulation, it cannot circulate without strong heating).