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Single-circuit gas boilers are devices with one heat exchanger designed to heat the coolant in heating systems. The factory equipment does not provide for their use for hot water supply. Some modifications allow organizing hot water supply – they can be paired with an indirect heating boiler.
Advantages of single-circuit gas boilers
Experts often speak in favor of single circuit heaters. They advise them to choose for heating a private house. The following arguments are given:
- The price is much lower than for double-circuit ones.
- Large assortment – it is easy to choose the best option.
- Automatic adjustment allows you to choose the right operating mode for economical gas consumption.
- With the help of several single-circuit heaters, a heating system with certain characteristics and capabilities can be created. The most common scheme is a cascade connection of devices. With cascading, you can provide high system power and extend its life.
- Simple and reliable design.
Installation method
If the buyer has already decided on the brand, you can proceed to the selection of suitable parameters. Installation method:
- Wall. Such a miniature boiler room is efficient and safe. Suitable for heating small rooms – up to 200 m². This boiler differs from floor versions in lower productivity. The weight of the wall versions is within 50 kg. The attachment takes up little space, so owners of small living quarters choose them. To increase the power, two wall-mounted appliances can be connected in parallel. What choice to make – two mounted boilers or one floor, each user decides for himself, based on his preferences and financial capabilities.
- Floor. Powerful devices capable of heating areas of more than 200 m². They are chosen by the owners of large private houses and country cottages.
Requirements for the room
When choosing a model, consider your capabilities: is there a room in the house / apartment that meets the requirements of SNiP (SNiP 31-02-2001, DBN V.2.5-20-2001, SNiP II-35-76, SNiP 42-01-2002 and SP 41-104-2000).
According to current regulations, the installation of gas equipment is allowed in rooms from 4 m² with a ceiling height of 2,5 m². The room should be well ventilated and have an openable window. It is mandatory to install an electric valve or a gas analyzer to enhance safety. The first is triggered in emergency situations, blocking the flow of fuel, the second controls the leakage of gas.
How to choose power
The power of the boilers is selected taking into account the area and volume of the premises. The most elementary way to determine power is 10 watts per 1000 m². The degree of insulation must also be taken into account: for non-insulated houses and corner apartments, it is recommended to install a device with a power reserve of 15-20%.
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Material selection
Products made of steel are several times lighter than cast-iron counterparts. But the service life of steel versions is half as long – this is important to consider when choosing. Steel corrodes faster, and sudden changes in temperature and condensate intensify destructive processes.
Quality balls
This indicator is rarely taken into account when choosing a boiler. We are talking about the resistance of the combustion chamber, on which the efficiency of fuel consumption depends. The recommended parameters are 1,5 mbar. You should not take a model with a firebox resistance of 8 mbar – it will quickly use up the resource, as it is not suitable for operation in conditions of unstable gas pressure.
The combustion chamber
Manufacturers offer two design solutions:
- The atmospheric type is a classic version of a gas heater. Such models are also called convection. They take oxygen for the combustion process from the room in which they are installed, so it is extremely important to ensure constant supply ventilation. Exhaust gases are discharged through the chimney using natural draft. Management of such modifications is most often carried out by mechanical and temperature controllers. Piezo ignition is used to start.
- Turbocharged type – models with a closed combustion chamber. They represent a more modern approach to gas equipment. Oxygen is forced into the furnace from outside. Air intake and exhaust gases are carried out through a coaxial pipe. Turbines are installed to circulate the flows. Among models with a closed firebox, condensing boilers stand out – this is the last word in gas heating equipment. They have improved performance due to the accumulation of heat from the exhaust gases. Their efficiency reaches 108-109%. Condensing heaters allow you to save up to 40% of gas, but their price is much higher than for conventional turbocharged devices.
Atmospheric versions are more suitable for private houses with ready-made chimneys. For turbocharged ones, a coaxial chimney is needed, which is organized in the wall.
Which heat exchanger to choose
The manufacturer offers three options for heat exchangers:
- made of stainless steel;
- enameled steel;
- copper.
Due to the desire for less weight, and perhaps because of economy, the walls of the heating element are often made too thin, which accelerates the burnout of the metal. The average service life of a modern heat exchanger reaches 20 years.
When choosing a model with a steel heat exchanger, you need to take into account that various additives can be added to steel that affect the choice of coolant. It is imperative to read the instructions in order to know which coolant can be used in a particular modification.
For example, not every option is suitable for antifreeze. If it is said that the heating element is unstable to chemical attack, it is forbidden to use antifreeze. Violation of this rule will lead to a reduction in the life of the device and the denial of warranty service.
What are the burners
- Single-stage burners are installed in non-volatile devices. The burner keeps the heat carrier heating temperature based on the on and off mode. The igniter burns constantly.
- Two-stage burners have two operating modes – at 30 and 100% of the rated power. Performance shifts seamlessly to save fuel. The burner is constantly working, it does not turn off. When the coolant is heated to the desired temperature, the flame power gradually decreases to 30%. Electrical ignition is used. Changes are monitored by automation, so all versions with two-stage burners depend on the mains.
- In modulating burners, the power varies in the range of 10-100%. The work is monitored by electronic automation. The strength of the flame varies depending on the pressure in the water supply and the temperature of the coolant. Modulating burners operating on liquefied gas are especially economical. The ratio in the gas-air mixture is selected automatically, which reduces incomplete combustion of fuel to a minimum.
Principle of operation
Single-circuit models have a simple and thoughtful design, in which a certain perfection has already been achieved. Essential elements:
- burner device;
- heat exchanger;
- automation;
- safety system.
Features of functioning depend on the type of combustion chamber. Above, we examined the difference between smoke removal and air injection in turbocharged and atmospheric boilers. The heat carrier is heated for all modifications according to one scheme:
- Turning on the burner.
- Heating of the heat exchanger in which the coolant circulates.
- The flow of heated coolant into the heating system. Having given off heat, water or antifreeze is sent to the heat exchanger through the return pipeline.
In models equipped with modulating burners, automation controls the intensity of the flame and the heating of the coolant. In automatic systems, user intervention is not required – it is enough to start the device at the beginning of the season, and you can not participate in its operation. Modern devices are equipped with a large number of sensors, safety valves, relays and thermostats that control all processes.
How to organize hot water supply
To provide the house with hot water for domestic needs, having a single-circuit heating apparatus, you need to install an indirect heating boiler. The water in it is brought to the desired temperature by means of a coil placed in containers. The liquid in the coil itself is heated by the boiler. A sensor in the storage tank monitors the water temperature. As soon as it reaches a predetermined level, the liquid stops circulating, heating stops.
The best single-circuit boilers
Baxi FOURTECH 1.24 F
The demanded modification with wall installation has a closed type of firebox. Oxygen is forcibly injected by means of a turbocharger. Smoke removal is also mandatory. Burner with power modulation, operating range – 9-24 kW.
The heat exchanger in Baksi is made of copper. A circulation pump is installed, there is an expansion tank of 6 liters, which compensates for the expansion of the liquid when heated. For convenient use, indication of modes, auto-ignition and a built-in thermometer are provided. Reliable overheating protection system: there is a gas control and a safety valve. The device performs a self-diagnosis. Efficiency – 93%. The estimated cost is 33 rubles.
User reviews indicate problems regarding the operation of the gas valve. But according to experts, taking into account the cost and quality, this particular model is one of the best among imported analogues.
Protherm Medved 50 PLO
Floor standing device. The classic version is an atmospheric burner and an open firebox. This is a high power gas heater – 44,5 kW. The miniature boiler room has a built-in boiler with a capacity of 110 liters, with which you can organize hot water supply. Cast iron heat exchanger installed.
The service life declared by the manufacturer is 20 years. Differs in economical gas consumption – 5,2 m³ / h. Efficiency – 92%. The disadvantage of the Proterm Medved apparatus is that it requires a certain level of pressure in the pipes. The estimated price is 70 rubles.
Neva Lux 8618
Compact heater from the domestic company Gazapparat. This low power version (18 kW) is designed for households up to 180 m². The firebox is open, and in the room where the Neva Lux 8618 is mounted, there should be a traditional chimney and good ventilation. The device works almost silently, since there are no turbines and fans, natural draft is used.
The heat exchanger is copper, and the efficiency is at the level of 90%. Consumption of natural gas – 2,13 m³ / h, liquefied gas – 1,59 kg / h.
Reviews
Neva Lux 8618: Rodion Z., Rostov region
I bought the device back in 2014, paid about 13 rubles. The fourth season is running in a fifty-year-old house with an area of 000 square meters. The thickness of the walls is no more than 52 cm. The house warms up perfectly even at minus 20-27 degrees – although we consider the South, the frosts are severe. And even then the temperature does not fall below 28 degrees, and the temperature in the house is 60-23 degrees. Over the years, nothing has broken and nothing has changed. I put a filter on the return line, which I change every season. The pump is running at 25st speed. Gas consumption together with a stove and column – no more than 1 cubic meters. According to the previous boiler (I had Zhytomyr), I judge that the consumption has decreased.
Protherm Medved 50 KLZ: Tatiana L., Murom
The model is good, but very sensitive. Of the benefits – it does not break, economical gas consumption, easy to manage, there is a display and self-diagnosis. Of the minuses – you need a stable voltage. Works since 2015. At that time, they paid 28 rubles. In general, they are satisfied with the work.
Gas heaters with a single circuit are a cost-effective and efficient solution for organizing heating. The absence of a secondary circuit simplifies the design and increases the reliability of the device. This option is ideal for consumers who do not need to provide domestic hot water. If there is such a task, you can pay attention to boilers that allow you to organize hot water using an indirect heating boiler (BKN).