Single-circuit gas boilers - devices with one heat exchanger, designed to heat the coolant in heating systems. Factory equipment does not provide for their use for hot water supply. Some modifications allow you to organize domestic hot water - they can work in tandem 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 dual-circuit.
- Large assortment - it is easy to choose the best option.
- Automatic adjustment allows you to choose the right mode for economical gas consumption.
- With the help of several single-circuit heaters, a heating system can be created with certain characteristics and capabilities. The most common scheme is the cascade connection of devices. When cascaded, it is possible to ensure 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 with 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 by lower productivity. The weight of the wall versions is within 50 kg. The attachment takes up little space, so they are chosen by the owners of small residential premises. To increase power, you can turn on two wall-mounted devices in parallel. Which choice to make - two mounted boilers or one floor, each user decides for himself, based on their preferences and material 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.
Room requirements
When choosing a model, consider your possibilities: is there a room in the house / apartment that is suitable for 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 standards, 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. To enhance safety, an electric valve or gas analyzer is required. The first is triggered in emergency situations, blocking the flow of fuel, the second - controls the gas leak.
How to choose power
The power of the boilers is selected taking into account the area and volume of the premises. The most basic way to determine power is 1000 watts per 10 m². The degree of insulation must also be taken into account: for non-insulated houses and corner apartments, it is recommended to install an apparatus 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 low - this is important to consider when choosing. Steel is more susceptible to corrosion, and sudden changes in temperature and condensation reinforce destructive processes.
Firebox quality
This indicator is rarely taken into account when choosing a boiler. We are talking about the resistance of the combustion chamber, which determines the efficiency of fuel consumption. Recommended parameters are 1.5 mbar. You should not take a model with a furnace resistance of 8 mbar - it will quickly consume a resource, as it is not suitable for operation under 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 fumes are vented 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 firebox from the street. Air intake and exhaust gas is carried out through a coaxial pipe. Turbines are installed to circulate the flows. Condensing boilers stand out among the models with a closed firebox - this is the last word in gas heating equipment. They have improved characteristics due to the accumulation of heat from the exhaust gases. Their efficiency reaches 108-109%. Condensation heaters can save up to 40% of gas, but their price is much higher than conventional turbocharged devices.
Atmospheric versions are more suitable for private houses with prefabricated chimneys. For turbochargers, however, you need a coaxial chimney, which is organized in the wall.
How to choose a heat exchanger
The manufacturer offers three options for heat exchangers:
- from stainless steel;
- enameled steel;
- copper.
Due to the desire for less weight, and possibly due to economy, the walls of the heating element are often made too thin, which accelerates the burnout of the metal. The average life of a modern heat exchanger reaches 20 years.
When choosing a model with a steel heat exchanger, you need to consider that various additives that affect the choice of coolant can be added to steel. It is necessary to read the instructions to know which coolant can be used in a particular modification.
For example, not every option is suitable for antifreeze. If it is said about the instability of the heating element to a chemical effect, antifreeze is prohibited. Violation of this rule will lead to a decrease in the service life of the device and a refusal of warranty service.
What are the burners
- Single-stage burners are installed in non-volatile devices. The burner device holds the heating medium temperature based on the on and off mode. The ignitor burns constantly.
- Two-stage burners have two operating modes - 30 and 100% of the rated power. Performance switches smoothly, which saves fuel. The operation of the burner is ongoing, it does not turn off. When the coolant is heated to the desired temperature, the flame power gradually decreases to 30%. Electric ignition is used. The changes are monitored automatically, so all versions with two-stage burners depend on the mains.
- In modulation burners, the power varies in the range of 10-100%. The work is monitored by electronic automation. The flame strength 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 minimizes incomplete combustion of fuel.
Principle of operation
Single-circuit models have a simple and thoughtful design in which a certain perfection has already been achieved. Main elements:
- burner device;
- heat exchanger;
- automation;
- safety system.
Features of operation depend on the type of combustion chamber. Above, we examined the difference between smoke removal and air injection in turbocharged and atmospheric boilers. Heating of the coolant occurs in all versions according to one scheme:
- Turning on the burner.
- Heating of the heat exchanger in which the coolant circulates.
- The receipt of the heated coolant in the heating system. Having given off heat, water or antifreeze is sent to the heat exchanger through a return pipe.
In models equipped with modulation burners, automation controls the intensity of the flame and the heating of the coolant. In automatic systems, no user intervention is required - just start the device at the beginning of the season, and you can not participate in its work. 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 device, 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 a container. The fluid in the coil itself is heated by the boiler. A sensor in the storage tank monitors the temperature of the water. As soon as it reaches a predetermined level, the liquid ceases to circulate, heating stops.
The best single-circuit boilers
Baxi FOURTECH 1.24 F
The popular modification with wall installation has a closed type of firebox. Oxygen is forced by turbocharging. Smoke removal is also mandatory. Burner with power modulation, operating range - 9-24 kW.
The heat exchanger at Baksi is made of copper. A circulation pump is installed, there is an expansion tank of 6 l, which compensates for the expansion of the liquid when heated. For convenient use, an indication of modes, automatic ignition and a built-in thermometer are provided. Reliable overheat protection system: there is a gas control and safety valve. The device conducts a self-test. Efficiency - 93%. Estimated cost - 33 000 rubles.
User reviews indicate problems with the operation of the gas valve. But according to experts, given the cost and quality, this particular model is one of the best among imported analogues.
Protherm Medved 50 PLO
The device is a floor type. The classic version is an atmospheric burner and an open firebox. This is a gas heater of high power - 44.5 kW. The miniature boiler room has a built-in boiler with a capacity of 110 liters, with its help it is possible to organize hot water supply. Cast iron heat exchanger installed.
The operating life declared by the manufacturer is 20 years. It 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. Estimated price - 70 000 rubles.
Neva Lux 8618
Compact heater from the domestic company "Gazapparat". This low-power version (18 kW) is designed for households with an area of 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%. Natural gas consumption - 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 13,000 rubles. The fourth season works in the house, which is fifty years old, with an area of 52 squares. The thickness of the walls is no more than 20 cm. The house perfectly heats even at minus 27-28 degrees - although the South is considered to be here, frosts are severe. And even then, the temperature does not drop below 60 degrees, and the temperature in the house is 23-25 degrees. Over the years, nothing has broken and nothing has changed. I put a filter on the back, which I change every season. The pump runs at 1st speed. Gas consumption together with a stove and column - no more than 350 cubic meters. According to the previous boiler (I had Zhytomyr) I judge that consumption has decreased.
Protherm Bear 50 KLZ: Tatyana L., Murom
The model is good, but very sensitive. Of the advantages - it does not break, economical gas consumption, easy to operate, there is a display and self-diagnosis. Of the minuses - you need a stable voltage. It has been working since 2015. At that time, they paid 28,000 rubles. In principle, we are satisfied with the work.
Single-circuit gas heaters are a cost-effective and efficient solution for organizing heating. The absence of a second circuit simplifies the design and increases the reliability of the device. This option is ideal for consumers who do not need to provide hot water. If this is the same task, you can pay attention to the boilers that allow you to organize a hot water supply using an indirect heating boiler (BKN).