05.09.2018
They are almost never equipped with circulation pumps, a safety group, adjustment and control devices. Everyone solves these issues on their own, choosing a heating device piping scheme in accordance with the type and features of the heating system. Not only the efficiency and productivity of heating, but also its reliable, trouble-free operation depends on how correctly the installation of the heat generator is carried out. That is why it is important to include components and devices in the circuit that will ensure the durability of the heating unit and its protection in case of emergency. In addition, when installing a solid fuel boiler, you should not abandon equipment that creates additional convenience and comfort. With the help of a heat accumulator, it is possible to solve the problem of temperature differences during the reboot of the boiler, and an indirect heating boiler will provide the house with hot water. Thinking about connecting a solid fuel heating unit in accordance with all the rules? We will help you with this!
However, if the rooms warm up afterwards, hydraulic adjustment is recommended in connection with the renewal of the heating system. The hydraulic adjustment is especially useful when using condensing boilers. These devices only operate at their best possible efficiency if the return temperature is below the temperature at which water condenses from the boiler flue gas. special occasions are single-pipe heating systems, especially in apartment buildings, as well as buildings with underfloor heating or mixed floor heating and radiator heating.
Typical piping schemes for solid fuel boilers
The complexity of controlling the combustion process in solid fuel boilers leads to a large inertia of the heating system, which negatively affects the convenience and safety during operation. The situation is further complicated by the fact that the efficiency of units of this type directly depends on the temperature of the coolant. For effective work heating, the piping must ensure the temperature of the heating agent in the range of 60 - 65 ° C. Of course, if the equipment is not properly integrated, such heating at a positive temperature "overboard" will be very uncomfortable and uneconomical. In addition, the full operation of the heat generator depends on a number of additional factors - such as heating system, the number of circuits, the presence of additional energy consumers, etc. The strapping schemes presented below take into account the most common cases. If none of them meets your requirements, then knowledge of the principles and features of the structure of heating systems will help in the development of an individual project.
Hydraulic regulation can also be carried out using these heating systems in principle, but is usually associated with much higher costs. Accurate characterization of the heating system boiler is only possible if the heat loss of a structural furnace can be relatively labor intensive. This calculation of heat load ≡ Heating load ≡ Heating load is the heating power that must be constantly supplied to the room in order to maintain the temperature in the space, therefore it must be as large as the sum of heat loss from conduction and ventilation.
System open type with natural circulation in a private house First of all, it should be noted that open gravity-type systems are considered the most suitable for solid fuel boilers. This is due to the fact that even in emergency cases associated with a sharp increase in temperature and pressure, heating is likely to remain airtight and efficient. It is also important that the functionality of the heating equipment does not depend on the availability of power. Considering that wood-fired boilers are installed not in megacities, but in areas remote from the benefits of civilization, this factor will not seem so insignificant to you. Of course, this scheme is not without drawbacks, the main of which are:
The assessment should be made on the basis of understandable rules, for example, according to comparable values for rooms from previous years or comparable rooms in the relevant reporting period. In this case, all heating costs are distributed according to a fixed scale, usually square meter. by experience. Calculation regulation.
What is the required boiler capacity? For example, with the help of subsequent thermal insulation ≡ Thermal insulation≡ Thermal insulation reduces heat flow from the hot to cold side of the component. For this purpose, substances with low thermal conductivity are introduced as a layer between hot and cold. An important water retention is achieved with the help of a vacuum. In addition, sleeping air retains heat flow very well.
- free access of oxygen to the system, which causes internal corrosion of pipes;
- the need to replenish the coolant level due to its evaporation;
- uneven temperature of the heat agent at the beginning and at the end of each circuit.
A layer of any mineral oil 1 - 2 cm thick poured into the expansion tank will prevent oxygen from entering the coolant and reduce the rate of evaporation of the liquid. Despite the shortcomings, the gravitational scheme is very popular due to its simplicity, reliability and low cost.
Re-evaluation is not detrimental to oil or gas condensing boilers and may even make sense in some cases. For low temperature boilers ≡ Low temperature boilers ≡ A low temperature boiler is a boiler that can also be used in continuous operation with a low heating water inlet temperature of 35 to 40 degrees Celsius and in which this can lead to condensation in the exhaust gases containing water vapor. Level standard use low temperature boiler is more than 90%.
Condensing heaters achieve an even higher standard efficiency of 100%. over-measurement should be avoided. To ensure the safe removal of exhaust gases from the heating system, the heating and the chimney must match. Previously, the interaction between the boiler and the chimney was much less important. The adaptation of the chimney to the boiler was in the background. The high flue gas temperatures of the boilers at that time also ensured that the flue gases were discharged without damage, even in the case of large chimney cross-sections, and the chimney was dry.
When deciding to carry out installation in this way, please note that for normal circulation of the coolant, the boiler inlet must be at least 0.5 m below the heating radiators. The supply and return pipes must have slopes for normal circulation of the coolant. In addition, it is important to correctly calculate the hydrodynamic resistance of all branches of the system, and in the design process, try to reduce the number of shut-off and control valves. The correct operation of the system with natural circulation of the coolant also depends on the installation location. expansion tank- it must be connected at the highest point.
However, the exhaust gases of modern low-temperature and condensing boilers have very low temperatures due to energy-saving operation. In addition, when replacing an old boiler, the rated heat output of the boiler is adapted to the actual, possibly reduced heat load of the building. This usually results in reduced performance compared to an older boiler with big size. Due to the existing chimney, significantly lower exhaust gas volumes with lower exhaust gas temperatures will be transferred after the replacement of the old boiler.
Closed system with natural circulation
Installing a membrane-type expansion tank on the return line will avoid the harmful effects of oxygen and eliminate the need to control the level of the coolant. When deciding to equip the gravity system with a hermetic expansion tank, consider the following points:
Why are chimneys damp? The hot exhaust gas that exits the combustion chamber of the boiler contains water vapor. If this exhaust gas is cooled to a certain temperature, water vapor becomes water and is deposited on cooler surfaces. The temperature of the flue gases in the humidified chimneys must be high enough to prevent condensation in the chimney, otherwise this could lead to moisture penetration or.
The relevant standards and building codes require precise coordination of the exhaust system with the heat source. The chimney must be planned and constructed in such a way that exhaust gases can be removed without mechanical assistance and that damage to the chimney or the building is avoided.
- the capacity of the membrane tank must contain at least 10% of the volume of the entire coolant;
- a safety valve must be installed on the supply pipe;
- the highest point of the system must be equipped with an air vent.
Additional devices that are included in the boiler safety group (safety valve and air vent) will have to be purchased separately - manufacturers very rarely complete units similar devices. The safety valve allows the coolant to be discharged if the pressure in the system exceeds a critical value. The normal working indicator is considered to be a pressure from 1.5 to 2 atm. The emergency valve is set to 3 atm.
The following requirements for the flue system must be observed. If the chimney is located on an outside wall, there is a risk that the exhaust gas will not get the necessary thermal buoyancy and that water vapor will condense on the chimney walls. In many cases, the existing chimney will be replaced by the aforementioned chimney. no longer meet the requirements.
Every year, the chimney cleaner confirms good exhaust gas values. "What else do you need?", you may wonder. "A whole lot" is our answer. More energy and save more money for the environment, more comfort, more operational security, learn more to trust the future security. The deflection of the chimney determines whether the quality of combustion and the loss of exhaust gases during burner operation comply with legal requirements. He checks if the pipe is working and the system is safe.
Features of systems with forced movement of the coolant
In order to equalize the temperature in all areas, a closed heating system is integrated circulation pump. Since this unit can provide forced movement of the coolant, the requirements for the installation level of the boiler and compliance with slopes become negligible. However, you should not give up the autonomy of natural heating. If a bypass branch called a bypass is installed at the outlet of the boiler, then in the event of a power outage, the circulation of the heating agent will be provided by gravity forces.
Even if he reassures you of ideal values, it doesn't make much difference to the economy of your system. After all, the old boiler has to work constantly with a high temperature. all year round. Especially during the transitional months or even in summer, when the boiler is only needed to heat drinking water, high cooling and/or heat is generated, which is generally much higher than the flue gas losses measured when passing through the chimney.
Not so with a new boiler. Here, the boiler water temperature is automatically adjusted to the appropriate outside temperature. If heat is not required, they will even turn off completely. If the boiler is 10 years old or more, then it is worth dealing with a new heating system. New system saves up to 30% energy and costs. You have a clear plus in comfort, work safety, environmental protection and safety in order to further comply with legal requirements.
The electric pump is installed on the return line, between the expansion tank and the inlet fitting. Due to the low temperature of the coolant, the pump operates in a more gentle mode, which increases its durability. The installation of a circulation unit on the return is also necessary for safety reasons. When water boils in the boiler, the formation of steam is possible, the entry of which into the centrifugal pump is fraught with a complete cessation of the movement of the liquid, which can lead to an accident. If the device is installed at the inlet to the heat generator, then it will be able to circulate the coolant even in the event of emergency situations.
Operational safety: Heating is required only when required
Of course, it would be exaggerated to think that your old heating system will give up its spirit in the coming days with a big blow. No, if she does, she will probably do it quietly and calmly - without warning. In any case, you can show new materials and features without any obligation in our showrooms.
Operating costs: is this what he wants?
You will notice high efficiency and long term boiler service, which is easy to maintain. How much is your oil and gas worth, check your bill regularly. It is not easy to see if your heating system is economically viable. Perhaps it even generates heat where no one is needed: Or it's just oversized.
Connection via manifolds
If it is required to connect several parallel branches with radiators, a water heated floor, etc. to a solid fuel boiler, then balancing the circuits is required, otherwise the coolant will follow the path of least resistance, and the rest of the system will remain cold. For this purpose, one or more collectors (combs) are installed at the outlet of the heating unit - switchgears with one input and multiple outputs. Mounting combs opens wide opportunities for connecting several circulation pumps, allows you to supply a heat agent of the same temperature to consumers and regulate its supply. The only disadvantage of this type of strapping can be considered a complication of the design and an increase in the cost of the heating system.
The development of harmful exhaust gases is closely related to consumption and use. Boilers that consume a lot also produce a lot of exhaust gases. Key words: forest death, greenhouse effect. Old boilers consume about a third of the fuel and produce more than 60 percent of pollutants than new boilers.
New burners with modern technology have particularly economical combustion with favorable values, so that they still do not meet the requirements of the Blue Angel environmental label and the Swiss Air Pollution Regulation.
A separate case of collector piping is a connection with a hydraulic arrow. Its difference from a conventional collector lies in the fact that this device acts as a kind of intermediary between the heating boiler and consumers. Made in the form of a pipe large diameter, the hydraulic arrow is installed vertically and connected to the inlet and pressure pipes of the boiler. At the same time, the insertion of consumers is done at different heights, which allows you to choose the optimal temperature for each circuit.
Operational safety, cost, environment, ease of use. You may be thinking: “Yes, such a modern heater that I already liked.” And you might also think: But it's worth it again. After all, it's not just about buying the purchase price. Then the account looks completely different.
Then you could say, "I can't put off that much." Be sure to have this account set up for your home by a specialist. He also knows funding, for example, for solar and condensing technology. What is a return? Where and why is the technology used? How is backflow increased? What are the benefits of an efficient heating system?
Installation of emergency and control systems
Alarm and control systems serve several purposes:
- protection of the system from depressurization in the event of an uncontrolled increase in pressure;
- temperature control of individual circuits;
- protection of the boiler against overheating;
- prevention of condensation processes associated with a large difference in supply and return temperatures.
To solve the problems of system safety, a safety valve, an emergency heat exchanger or a natural circulation circuit are introduced into the piping scheme. As for the issues of regulating the temperature of the heat agent, thermostatic and controlled valves are used for this purpose.
Modern heating systems only work optimally when certain operating temperatures are not exceeded or exceeded. To prevent excessive cooling of the return, use a so-called return lift. We explain to you in this article what it is with a rollback and how to implement it technically. You will also find out which heating systems have a reverse rise and which do not.
Free 5 suggestions for your new heater inquiry
Functional implementation of backflow lifting
Reverse lift is a technology used in heating systems hot water to quickly reach and maintain the desired minimum temperature in the heating circuit heater. The rise of the return flow is achieved through the use of a special mixing valve. It mixes under the cold return a variable part of the hot heating water that has been heated by the heat source. This results in usually faster and more high temperature coolant returning back to the heat generator.Trim with a three-way valve.
A solid fuel boiler is a heating unit of periodic operation, therefore it is at risk of corrosion due to condensate that falls on its walls during heating. This is due to the ingress of too cold coolant from the return into the heat exchanger of the heating unit. The danger of this factor can be eliminated with the help of a three-way valve. This device is an adjustable valve with two inlets and one outlet. On a signal from the temperature sensor, the three-way valve opens the hot coolant supply channel to the boiler inlet, preventing the occurrence of a dew point. As soon as the heating unit enters the operating mode, the liquid supply in a small circle stops.
Therefore, in the heat exchanger flow and return flow with a lower temperature difference. The higher temperature of the return flow, which rises in this way, has a positive effect on the operation of the heating system, which can thus function optimally. The optimum operating temperature depends on the fuel being burned, more precisely on the so-called flue gas dew point.
At the same time, back-up lift is used to counteract damage that can occur, for example, when gases that accumulate during fuel combustion are heated to cool and condense. Condensation can damage the system because it causes effects such as pitting. Temperature differences can also cause stress leading to cracking.
A fairly common mistake is to install a centrifugal pump before a three-way valve. Naturally, with the valve closed, there can be no question of any circulation of fluid in the system. It will be correct to install the pump after the adjusting device. The three-way valve can also be used to control the temperature of the heating agent supplied to the consumers. In this case, the device is set to work in the other direction, mixing cold coolant from the return to the supply.
Scheme with buffer capacity
The low controllability of solid fuel boilers requires constant monitoring of the amount of firewood and draft, which significantly reduces the convenience of their operation. To load more fuel and at the same time not to worry about the possible boiling of the liquid will allow the installation of a buffer tank (heat accumulator). This device is a sealed tank that separates the heating unit from consumers. Due to the large volume, the buffer tank can accumulate excess heat and release it to radiators as needed. The mixing unit, which uses the same three-way valve, will help to adjust the temperature of the liquid coming from the heat accumulator.
Strapping elements that ensure the safety of the heating system
Except safety valve, which was mentioned above, the protection of the heating unit from overheating is solved using an emergency circuit, through which cold water is supplied to the heat exchanger from the water supply. Depending on the design of the boiler, the coolant can be supplied directly to the heat exchanger or a special coil installed in the working chamber of the unit. By the way, it is the latter option that is the only possible one for systems filled with antifreeze. Water supply is carried out using a three-way valve, which is controlled by a sensor installed inside the heat exchanger. The discharge of the "waste" liquid occurs through a special line connected to the sewer.
Scheme with connecting an indirect heating boiler
The piping with the connection of a boiler for hot water supply can be used for heating systems of all types. To do this, a special heat-insulated container (boiler) is connected to the water supply and the hot water supply system, and a coil is installed inside the water heater, which is cut into the heating agent supply line. Passing along this circuit, the hot coolant gives off heat to the water. Often, an indirect heating boiler is also equipped with heating elements, thanks to which it becomes possible to receive hot water in the warm season.
Proper installation of a solid fuel boiler in a closed-type heating system
A huge advantage of solid fuel boilers is that no permits are required for their installation. Installation is quite possible to carry out with your own hands, especially since this does not require any special tools or special knowledge. The main thing is to approach the work responsibly and observe the sequence of all stages.
Boiler room arrangement. The disadvantage of heating units used for burning wood and coal is the need for a special, well-ventilated room. Of course, it would be possible to install a boiler in the kitchen or bathroom, however, the periodic emission of smoke and soot, dirt from fuel and combustion products make this idea unsuitable for implementation. In addition, the installation of incineration equipment in living rooms it is also unsafe - the release of fumes can lead to tragedy. When installing a heat generator in a boiler room, several rules are observed:
- the distance from the furnace door to the wall must be at least 1 m;
- ventilation ducts must be installed at a distance not higher than 50 cm from the floor and not lower than 40 cm from the ceiling;
- the room should not contain fuel, lubricants and flammable substances and objects;
- the base platform in front of the ash pan is protected with sheet metal dimensions not less than 0.5x0.7 m.
In addition, at the installation site of the boiler, an opening is provided for the chimney, which is brought out. Manufacturers indicate the configuration and dimensions of the chimney in the technical data sheet, so you don’t need to invent anything. Of course, if the need arises, then the requirements of the documentation can be deviated, however, in any case, the channel for the removal of combustion products should provide excellent traction in any weather. When installing a chimney, all joints and cracks are sealed with sealing materials, and windows are also provided for cleaning the channels from soot and a condensate trap.
Preparing to install the heating unit
Before installing the boiler, a piping scheme is selected, the length and diameter of pipelines, the number of radiators, the type and number of additional equipment and shut-off and control valves are calculated. Despite all the variety of design solutions, experts recommend choosing combined heating, which can provide forced and natural circulation of the coolant. Therefore, when calculating, it is necessary to consider how a parallel section of the supply pipeline (bypass) with a centrifugal pump will be installed and provide for the slopes necessary for the operation of the gravity system. Do not give up on the buffer capacity. Of course, its installation will entail additional costs. However, this type of accumulator will be able to even out the temperature curve, and one bookmark of fuel will last for a longer time.
A solid fuel boiler with an additional circuit, which is used for hot water supply, will provide special comfort. Given the fact that due to the installation of a solid fuel unit in a separate room, the length of the DHW circuit increases significantly, an additional circulation pump is mounted on it. This will eliminate the need to drain cold water while waiting for hot water to come out. Before installing the boiler, it is imperative to provide a place for the expansion tank and do not forget about devices designed to reduce pressure in the system in critical situations. A simple strapping scheme that can be used as a working draft is shown in our figure. It integrates all the equipment discussed above and ensures its correct and trouble-free operation.
Installation and connection of a solid fuel heat generator
After carrying out all the necessary calculations and preparation of equipment and materials, installation begins.
- Install in place, level and fix the heating unit, after which a chimney is connected to it.
- They fix heating radiators, install a heat accumulator and an expansion tank.
- Mount the supply pipeline and bypass, on which the circulation pump is installed. On both sections (straight and bypass) install Ball Valves so that the coolant can be transported by forced or natural means. We remind you that a centrifugal pump can only be installed with the correct orientation of the shaft, which must be in a horizontal plane. The manufacturer indicates the schemes of all possible mounting options in the instructions for the product.
- The pressure line is connected to a heat accumulator. I must say that both the inlet and outlet pipes of the buffer tank must be installed in its upper part. Thanks to this, the amount of warm water in the container will not affect the readiness. heating circuit. Be sure to note the fact that the cooling of the boiler during the reboot period will reduce the temperature in the system. This is due to the fact that at this time the heat generator will work as an air heat exchanger, transferring heat from the heating system to the chimney. To eliminate this shortcoming, separate circulation pumps are installed in the boiler and heating circuits. By placing a thermocouple in the combustion zone, it is possible to stop the movement of the coolant through the boiler circuit when the fire is extinguished.
- A safety valve and an air vent are installed on the supply line.
- They connect the emergency circuit of the boiler or install shut-off and control valves, which, when water boils, will open the line for its discharge into the sewer and the channel for supplying cold liquid from the water supply.
- Mount the return pipeline from the heat accumulator to the heating unit. Before the inlet pipe of the boiler, a circulation pump, a three-way valve and a sump filter are installed.
- Separately, an expansion tank is mounted on the return pipeline. Note! On pipelines that are connected to protection devices, stop valves are not installed. These areas should have as few connections as possible.
- The upper outlet of the heat storage tank is connected to a three-way valve and a heating circuit circulation pump, after which radiators are connected and a return pipeline is mounted.
- After connecting the main circuits, they begin to equip the hot water supply system. If the heat exchanger coil is built into the boiler, then it will be enough just to connect the cold water inlet and the outlet to the “hot” main to the corresponding pipes. When installing a separate indirect water heater, a circuit with an additional circulation pump or a three-way valve is used. In both cases, at the inlet of the cold water supply, check valve. It will block the path for the heated liquid to the "cold" water supply.
- Some solid fuel boilers are equipped with a draft regulator, the work of which is to reduce the flow area of the blower. Due to this, the air flow into the combustion zone is reduced and its intensity, and, accordingly, the temperature of the coolant decreases. If the heating unit has such a design, then they mount and adjust the drive of the air damper mechanism.
All threaded connections must be carefully sealed with sanitary flax and a special non-drying paste. After installation is completed, the coolant is poured into the system, turned on at full power centrifugal pumps and carefully inspect all connections for leaks. After making sure that there are no leaks, they kindle the boiler and check the operation of all circuits at maximum modes.
Features of the integration of a solid fuel unit into an open heating system
The main feature of open heating systems is the contact of the coolant with atmospheric air, which occurs with the participation of an expansion tank. This capacity is designed to compensate for the thermal expansion of the coolant, which occurs when it is heated. The expander is cut in at the highest point of the system, and in order to prevent hot liquid from flooding the room when the tank overflows, a drain pipe is connected to its upper part, the second end of which is led into the sewer.
The large volume of the tank forces it to be installed in the attic, so you will need additional insulation expander and the pipes that fit it, otherwise they may freeze in winter. In addition, it must be remembered that this element is part of the heating system, so its heat loss will lead to a decrease in temperature in the radiators. Since the open system is not hermetic, there is no need to install a safety valve and connect emergency circuits. When the coolant boils, the pressure will be released through the expansion tank.
Special attention should be paid to pipelines. Since the water in them will flow by gravity, the circulation will be influenced by the diameter of the pipes and the hydraulic resistance in the system. The last factor depends on turns, narrowings, level drops, etc., so their number should be minimal. In order to initially give the water flow the necessary potential energy, a vertical riser is mounted at the outlet of the boiler. The higher the water can rise along it, the higher the coolant speed will be and the faster the radiators will warm up. For the same purpose, the return inlet must be located at the lowest point of the heating system.
Finally, I would like to point out that in open systems It is preferable to use not antifreeze, but water. This is due to a higher viscosity, reduced heat capacity and rapid aging of the substance in contact with air. As for water, it is best to soften it and, if possible, never drain it. This will increase the service life of pipelines, radiators, heat generators and other heating equipment several times.
Solid fuel boiler piping - Emergency cooling valve
3. Protection against low temperature of the coolant in the "return" of the solid fuel boiler.
What will happen to a solid fuel boiler if its “return” temperature is below 50 °C? The answer is simple - a resinous coating will appear on the entire surface of the heat exchanger. This phenomenon will reduce the performance of your boiler, make it much more difficult to clean and, most importantly, can lead to chemical damage to the walls of the boiler heat exchanger. To prevent such a problem, it is necessary to provide appropriate equipment when installing a heating system with a solid fuel boiler.
The task is to ensure the temperature of the coolant that returns to the boiler from the heating system at a level not lower than 50 °C. It is at this temperature that the water vapor contained in the flue gases of a solid fuel boiler begins to condense on the walls of the heat exchanger (transition from a gaseous state to a liquid state). The transition temperature is called the "dew point". The condensation temperature directly depends on the moisture content of the fuel and the amount of hydrogen and sulfur formations in the combustion products. As a result of a chemical reaction, iron sulfate is obtained - a substance useful in many industries, but not in a solid fuel boiler. Therefore, it is quite natural that the manufacturers of many solid fuel boilers remove the boiler from the guarantee in the absence of a heating system. return water. After all, here we are not dealing with the burning of metal at high temperatures, but with chemical reactions that no boiler steel can withstand.
The simplest solution to the low return temperature problem is to use a thermal three-way valve (anti-condensation thermostatic mixing valve) . The thermal anti-condensation valve is a thermomechanical three-way valve that ensures the admixture of the coolant between the primary (boiler) circuit and the coolant from the heating system in order to achieve a fixed temperature of the boiler water. In fact, the valve lets the unheated coolant through a small circle and the boiler heats itself. After reaching the set temperature, the valve automatically opens the access of the coolant to the heating system and works until the return temperature drops below the set values again.
Solid fuel boiler piping - Anti-condensation valve
4. Protection of the heating system of a solid fuel boiler from operation without a coolant.
The operation of the boiler without a coolant is strictly prohibited by all manufacturers of solid fuel boilers. Moreover, the coolant in the heating system must always be under a certain pressure, which depends on your heating system. When the pressure in the system drops, the user opens the valve and fills the system up to a certain pressure.
In this case, there is a "human factor", which may well make mistakes. You can solve this issue with the help of automation.
Automatic make-up installation - a device that is adjusted to a certain pressure and connected to an open water tap. In the event of a decrease in pressure, the process of filling the system up to desired pressure will be completely automatic.
For everything to work correctly, some conditions must be met when installing the automatic make-up valve:
- it is necessary to mount the automatic make-up valve at the lowest point of the heating system;
- during installation it is necessary to leave access for cleaning or possible replacement valve;
- water from the water supply must be constantly supplied to the valve with pressure, and the water supply tap and the make-up valve must always be open.
Solid fuel boiler piping - Automatic make-up valve
5. Removal of air from the heating system of the solid fuel boiler.
The air in the heating system can cause a number of problems: poor circulation of the coolant or its absence, noise during pump operation, corrosion of radiators or elements of the heating system. To avoid this, it is necessary to bleed air from the system. There are two ways for this - the first one manually - we think over the installation of cranes at the highest point of the system and on the lifting sections and periodically pass these cranes, releasing air. The second way is to install an automatic air release valve. The principle of its operation is simple - when there is no air in the system, the valve is filled with water and the float is located at the top of the valve, and, through a hinged lever, seals the air outlet valve.
When air enters the valve chamber, the water level in the valve drops, the float moves down and through the articulated arm opens the air outlet on the outlet valve. As air escapes from the chamber, the water level rises and the valve returns to its upper position.
We have already described the device of the boiler safety group above when we talked about protection against high pressure coolant. Ideally, if you have installed a safety group, it has an automatic air release valve. Just make sure that the safety group is installed at the top of your heating system. If not, we recommend installing a separate automatic air release valve and permanently solve the problem of finding air pockets in your heating system.
Solid fuel boiler piping - Automatic air release valve
After installing the heating system, it is necessary to adjust the temperature regime. This procedure must be carried out in accordance with existing standards.
The requirements for the temperature of the coolant are set out in the regulatory documents that establish the design, installation and use engineering systems residential and public buildings. They are described in the State building codes and regulations:
- DBN (B. 2.5-39 Heat networks);
- SNiP 2.04.05 "Heating, ventilation and air conditioning".
For the calculated temperature of the water in the supply, the figure is taken that is equal to the temperature of the water at the outlet of the boiler, according to its passport data.
For individual heating to decide what should be the temperature of the coolant, should be taking into account such factors:
- Beginning and end heating season according to the average daily temperature outside +8 °C for 3 days;
- The average temperature inside the heated premises of housing and communal and public importance should be 20 ° C, and for industrial buildings 16°C;
- The average design temperature must comply with the requirements of DBN V.2.2-10, DBN V.2.2.-4, DSanPiN 5.5.2.008, SP No. 3231-85.
According to SNiP 2.04.05 "Heating, ventilation and air conditioning" (clause 3.20), the coolant limit values are as follows:
Depending on external factors, the water temperature in the heating system can be from 30 to 90 °C. When heated above 90 ° C, dust and paintwork begin to decompose. For these reasons sanitary norms prohibit more heating.
For calculation optimal performance special charts and tables can be used that define the norms depending on the season:
- With an average value outside the window of 0 °С, the supply for radiators with different wiring is set at a level of 40 to 45 °С, and the return temperature is from 35 to 38 °С;
- At -20 °С, the supply is heated from 67 to 77 °С, while the return rate should be from 53 to 55 °С;
- At -40 ° C outside the window for all heating devices set the maximum allowable values. At the supply it is from 95 to 105 ° C, and at the return - 70 ° C.
Optimal values in an individual heating system
H2_2Heating system helps to avoid many of the problems that arise with centralized network, and the optimum temperature of the coolant can be adjusted according to the season. In the case of individual heating, the concept of norm includes the heat transfer of a heating device per unit area of the room where this device is located. The thermal regime in this situation is provided design features heating appliances.
It is important to ensure that the heat carrier in the network does not cool below 70 °C. 80 °C is considered optimal. It is easier to control heating with a gas boiler, because manufacturers limit the possibility of heating the coolant to 90 ° C. Using sensors to adjust the gas supply, the heating of the coolant can be controlled.
It is a little more difficult with solid fuel devices, they do not regulate the heating of the liquid, and can easily turn it into steam. And it is impossible to reduce the heat from coal or wood by turning the knob in such a situation. At the same time, the control of heating of the coolant is rather conditional with high errors and is performed by rotary thermostats and mechanical dampers.
Electric boilers allow you to smoothly adjust the heating of the coolant from 30 to 90 ° C. They are equipped with an excellent overheating protection system.
One-pipe and two-pipe lines
The design features of a single-pipe and two-pipe heating network determine different standards for heating the coolant.
For example, for a single-pipe line, the maximum rate is 105 ° C, and for a two-pipe line - 95 ° C, while the difference between the return and supply should be, respectively: 105 - 70 ° C and 95 - 70 ° C.
Matching the temperature of the heat carrier and the boiler
Regulators help to coordinate the temperature of the coolant and the boiler. These are devices that create automatic control and correction of the return and supply temperatures.
The return temperature depends on the amount of liquid passing through it. The regulators cover the liquid supply and increase the difference between the return and supply to the level that is needed, and the necessary pointers are installed on the sensor.
If it is necessary to increase the flow, then a boost pump can be added to the network, which is controlled by a regulator. To reduce the heating of the supply, a “cold start” is used: that part of the liquid that has passed through the network is again transferred from the return to the inlet.
The regulator redistributes the supply and return flows according to the data taken by the sensor, and ensures strict temperature norms heating networks.
Ways to reduce heat loss
The above information can be used to correct calculation coolant temperature standards and tell you how to determine the situation when you need to use the regulator.
But it is important to remember that the temperature in the room is affected not only by the temperature of the coolant, outdoor air and wind strength. The degree of insulation of the facade, doors and windows in the house should also be taken into account.
To reduce the heat loss of housing, you need to worry about its maximum thermal insulation. Insulated walls, sealed doors, metal-plastic windows help reduce heat loss. It will also reduce heating costs.
Maintenance of a gas boiler with low productivity is expensive. Therefore, anyone who uses such a device wants to find optimal mode gas boiler operation, at which it will have the highest possible efficiency (coefficient useful action) at minimal cost fuel. This problem becomes especially urgent on the eve of the next heating season.
The performance of a gas boiler is influenced by various factors. If you haven't bought yet this device, but only plan to purchase it, please note that the main condition for its installation is the presence of a centralized gas supply. Some think they can get by bottled gas, but this will significantly increase costs. In this case, it is better to install electric heating.
Optimum performance depends on the following criteria:
- Boiler designs - they can be single-circuit, double-circuit, mounted, floor, etc.
- Efficiency - nominal and real.
- Proper organization of heating in the house: the power of the boiler must correspond to the area of \u200b\u200bthe heated premises.
- The technical condition of the equipment.
- Gas quality.
Now let's take a closer look at how each of the criteria can be optimized to maximize device performance.
Boiler design
Boilers are single-circuit and double-circuit. The first one will have to buy an indirect heating boiler so that it can heat water. The double-circuit option is preferable, as it is equipped with everything necessary for the production of hot water and heating the house. For ease of use, the priority mode in such a boiler is the supply of hot water. This means that when the water supply is turned on, the heating stops.
There are wall and floor gas boilers. The former have less power and can only heat a room up to 300 m². If your house is larger, you will need to purchase another wall-hung or floor-standing boiler.
Nominal and real efficiency
The instructions for any gas boiler indicate the nominal efficiency, usually it is 92-95%, for condensing models - about 108%. However, the real figure is usually 9-10% lower. Further reduces its presence various kinds heat loss:
- Physical underburning - this indicator depends on the volume of excess air in the unit during the gas combustion process. It is also affected by the temperature of the flue gases: the higher it is, the lower the efficiency of the boiler.
- Chemical underburning - this indicator varies depending on the volume of oxide carbon monoxide that comes from the combustion of carbon.
- Heat loss that escapes through the walls of the boiler.
Boost real efficiency devices in the following ways:
- Reducing the physical underburning rate by regularly cleaning soot on the pipeline and removing scale from the water circuit.
- Reducing the amount of excess air by installing a draft limiter on the chimney.
- By adjusting the position of the blower damper in such a way that Maximum temperature coolant.
- Regular cleaning of soot on the combustion chamber, which increases gas consumption.
To increase the efficiency of a gas boiler will allow replacing the chimney with a more innovative one. Most of Traditional branch pipes are too dependent on the weather. They were replaced by a coaxial chimney, which is resistant to temperature changes and is able to increase efficiency, as well as save fuel.
Note! Some owners of gas boilers make a mistake - they pour out the coolant and pour tap water. This is not worth doing, as new plumbing water, when heated, leaves scale on the walls of the pipeline.How to properly organize home heating with a gas boiler?
Matching the power of the heating boiler to the heated area of the room is a key factor in the quality of heating. This factor also affects the duration of uninterrupted operation of the unit.
In order to accurately calculate the required boiler power for a house, one should take into account the features of the structure, possible heat loss through walls and ceilings. It is quite difficult to make these calculations on your own, so it is better to hire a specialist who can correctly determine the optimal boiler power.Usually, 100 W of power per 1 m² is enough to heat a house built in accordance with all building codes. Based on this rule, we get the following table.
When buying gas boilers, it is better to give preference to modern foreign-made models, since their quality is higher compared to domestic ones. Also, more "advanced" units have additional setting functions, with which you can select the optimal mode of operation of the gas boiler.
Note! When choosing a gas boiler, it should be noted that its optimal power should be 70-75% of the maximum.Below is a video showing how to install optimal wall boiler mode.
Technical condition of the boiler
Its efficiency directly depends on the technical condition of the gas boiler. In order for it to last as long as possible and work in optimal mode, it is necessary regular care. It is important to clean the internal elements from soot and scale in a timely manner.
A frequent problem of a gas boiler, in which its performance decreases, is clocking. This means that the unit turns on too often due to excessive heating of the coolant. This usually occurs due to high power devices. Clocking leads to excessive consumption of gas and rapid wear of equipment. This problem is solved very simply - you should set the gas supply level to the minimum. You can do this by following the attached instructions.
Gas quality
The quality of the gas is the only factor that we cannot influence. An increased volume of moisture leads to an increase in gas consumption.
How to set the optimal mode?
There is such a thing as the optimal mode of a gas boiler. As mentioned above, the unit consumes fuel economically if it operates at 75% of maximum power. Most boilers are set to the temperature of the coolant. When it reaches the required value, the boiler turns off for a while. The user can determine which optimal operating temperature of the gas boiler it will suit you and install it. The value may change depending on weather conditions, for example, in winter the temperature of the coolant should be 70-80°C, and in spring or autumn it can be reduced to 55-70°C.
Modern models of gas boilers are equipped with temperature sensors, thermostats and automatic system mode settings. If your boiler does not have such equipment, it can be purchased at a specialized store and installed on almost any model. Using the thermostat, you can set the desired temperature in the room, which the gas boiler must maintain. Depending on it, the coolant will heat up and cool down at a certain frequency. This mode of operation provides for the automatic reaction of the boiler to temperature changes in the street or in the house. In addition, at night it is advisable to reduce the heat in the room by 1-2 ° C. Thus, automation will minimize gas consumption, and at the same time maintain the temperature in the room at the desired level. Note! Installing sensors and a thermostat will save up to 20% of gas.Some modern models boilers can change the mode of operation depending on the presence of people in the room. This makes it possible to maintain the optimum temperature at prolonged absence hosts. But still, it is not worth leaving the boiler in working condition for a long time unattended. Otherwise, in the event of an emergency power outage, the unit may fail.
If you find it difficult to independently reconfigure or adjust the operation of your gas boiler, contact the specialists.
The most economical boilers
Statistics and specifications indicate that gas boilers of foreign manufacturers have the highest efficiency. Manufacturers Baxi, Protherm, Buderus, Bosch have proven themselves well on the market.
If you have not yet made your choice, pay attention to condensing boilers - its efficiency is 10-11% higher than that of traditional ones, they are the most economical and powerful, but they are also not cheap. But low fuel consumption and long service life will pay off the money spent on it. Its principle of operation is different in that the products of fuel combustion do not escape in the form of gas, but pass through a stainless steel heat exchanger, heat water, cool down and fall out in the form of liquid condensate.
To achieve optimal operation of a gas boiler, you should maintain it in good condition, regularly clean it of soot and scale, and also equip it with an automatic room temperature control system. If you follow these recommendations, your unit will enjoy uninterrupted operation, low gas consumption and a cozy atmosphere in the house.
