Apartment buildings are connected to the central heating network, and buildings in the private sector are connected to an autonomous one. The quality of heating in both cases is affected by the life of the house, the condition of equipment and communications. Also important is a dependent or independent heating system, which differ in the type of connection diagram.
Dependent heat supply scheme
The dependent heat supply scheme provides for the communication of the heating network and internal communications in the house through the main pipes. Water from the heat distributor is supplied to the objects, that is, it moves from the central boiler room to the apartment.
A feature of the scheme is the dependence on the temperature of the coolant. If it reaches 95 degrees, water immediately flows to the heating pipes. When the temperature rises to 105 degrees, a mixing unit - an elevator is required. It mixes cold water from the radiators into the hot water in the line.
The advantages of a dependent circuit for heating include the reliability of the equipment and the absence of the need to control it. Installation work and the cost of materials are inexpensive, since additional DHW pipes are not laid - hot water is taken directly from the heating main.
Connection according to a dependent scheme is realized through a direct connection to the line, using an elevator, pumps on a jumper, a return and supply network, or in a mixed way. In the latter case, an elevator and a pump are installed.
With a dependent connection, mineral and mechanical impurities often remain in the water, which shortens the service life of the wiring.
Independent heat supply scheme
An independent heating circuit consists of a main and additional circulation circuits, separated by a heat exchanger. The heat carrier is directed from the CHPP or boiler house to the central heating point. Then it moves to the heat exchanger (main circuit), and then goes to the heat supply of the house (auxiliary circuit). Both circuits are isolated, the water does not mix.
In an independent line, the coolant moves forcibly - due to the circulation pump. Water flows through the heating devices constantly. There is an expansion tank in case of leaks.
Advantages and disadvantages of connections
Dependent schema
Water is supplied and supplied to heating and water supply from the heating main, which leads to a number of advantages:
- simplicity of design and inexpensive cost of subscriber devices;
- the ability of the system to withstand temperature fluctuations;
- smaller diameter of the reinforcement;
- efficiency of heat carrier consumption;
- low operating costs.
The negative factors of using a dependent heating system include:
- Formation of dirt, rust and scale in the lines. They enter aluminum and bimetallic devices and cause pipe rupture.
- Frequent pressure fluctuations, water hammer due to a decrease in water intake. The phenomena can lead to rupture of polymer reinforcement.
- Low quality of the heat carrier, despite the cleaning and desalination in the boiler room.
- Difficulty adjusting the temperature even with full bore valves.
To remove blockages, an additional sump is mounted on the mixer.
Independent scheme
In the presence of a closed circuit, water from the plate heat exchanger can be supplied to any distribution. The dependent heat supply scheme has several advantages:
- the temperature of the coolant in the pipes is regulated by the user;
- good indicators of energy saving;
- compatibility with any heat carrier;
- absence of impurities in the hot water supply line;
- the ability to purify and filter water in the circuits;
- no risk of pressure surges and water hammer.
The disadvantages of an independent connection include:
- complex service;
- impossibility of self-repair;
- large financial costs for the organization.
An independent line saves water consumption by 10-40%.
Dependence of systems on electricity
Energy dependence of systems is defined as the ability to operate with or without electricity. Non-volatile communications are mounted in conditions of prolonged light off. For the normal functioning of heating, several methods are used:
- Installation of an electric generator or inverter batteries. The devices start up power after the mains are de-energized.
- Providing non-volatile heat generation. You will need an automatic boiler - pellet, liquid fuel or gas. The equipment operates without electricity, but it is uneconomical for the main fuel.
- Creation of gravitational pressure. The liquid moves through the difference in density when heated and cooled. The heated water masses go up, the cooled ones go down. Gravitational pressure is created by installing the boiler at the lowest point, the slope of the horizontal pipeline along the movement of water.
For gravitational heating, pipes with a diameter of 35 to 50 mm will be needed.
When implementing circulating or volatile heat supply, you will need a circulating pump. The system is connected to pipes of any diameter; special convectors and underfloor heating also work for heating. The water temperature is maintained at a predetermined level. In the event of a power outage, generators are installed.
What system is justified in a private house
For production workshops, houses above 12 floors, an independent gravitational system is used - it ensures the quality of heating due to an even distribution of heat. Equipment and installation costs pay off when there is a large area. Specialists are engaged in calculations and selection of the scheme. They recommend installing several heat exchangers to heat the primary, secondary heating medium and the DHW line.
In the conditions of settlements, summer cottages, small enterprises, the technological features of heat supply are taken into account. There is practically no central heating in such places - individual heating is often used, with a separate boiler room. It needs to be equipped taking into account energy independence. For this purpose, boilers are used:
- Pellet. They are filled with special homogeneous granules - pellets from pressed shavings or husks. The owner loads fuel for several days, electricity is used only to power the screw engine.
- Pyrolysis. They work on the principle of afterburning gases in the secondary chamber. They run on electricity from generators. Air is pumped in with special valves.
- Top burning. The fuel is loaded with a slide and ignited from above.
- With forced air supply. Pellets or firewood are placed in a large single-chamber firebox. The blower has a fan and a damper that blocks air access.
The best option for a private house is a boiler, but it will require 20% more fuel in comparison with central heating.
Is it possible to make an independent system out of a dependent
The dependent circuit, through several technological methods, can be converted into an independent system with the implementation of heat supply using:
- Hopper and conveyor belts for solid fuel boiler. When fuel materials burn out, new portions enter the furnace on a transport belt. It is powered from the mains.
- Pyrolysis boiler. Combustion takes two stages. At the first, firewood is pyrolized with a minimum supply of oxygen, at the second, the residual gas is burned. An electric fan is used to create traction.
- Top burning equipment. Due to the smoldering of the upper layer, the device operates for 5 days on one fuel fill. Air masses are blown by an electric fan.
The best option for non-volatility is a gas boiler with manual ignition and a control thermostat for the flame.
With a dependent scheme, water enters the system through the elevator and mixes with the return masses. An independent system excludes this process - heating takes place through a heat exchanger. Heat supply can work in conjunction with electricity or autonomously. It is necessary to select the connection method according to the heating area and the type of object.
