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Gas heating technology is gaining more and more popularity. The operation of such equipment is beneficial even on liquefied gas, compared with the cost of electricity. A convection boiler is the most common type among heating appliances of this type. Among the large assortment of models, it is important to choose the one that is right for your home.
What is a convection boiler?
This type of device is often used for a private house with an area of more than 300 m². The principle of operation of the device is simple: gas enters the burner, the flame lights up, it heats the heat exchanger with water. The products of combustion are discharged through a connected chimney. The efficiency of the device is over 90%.
A convection gas boiler happens:
- single-circuit – designed only for heating the coolant for heating the house;
- double-circuit – provides housing with heating and hot water supply (DHW).
Installation is done in two ways:
- Floor – such units require a separate room or a large area; a solid foundation is provided for their installation.
- Wall-mounted – such models are compact, can be placed in any non-residential premises of the apartment.
Principle of operation and device
Heating appliances come with an open and closed combustion chamber. An open chamber boiler draws combustion air from the room and exhausts the exhaust gas through the chimney. A device with a closed chamber provides for a coaxial chimney. This is a “pipe in pipe” design: air enters one at a time to maintain the flame, and combustion products are removed at the other.
How does convective heating work? Inside the device there is a heat exchanger and a burner with flame modulation. With automatic or piezo ignition, gas enters the system, a spark is created and the burner ignites. The flame heats the heat exchanger through which the coolant moves. As soon as the liquid reaches the set temperature, the automation is activated and the heating stops. When the coolant cools, the thermocouple turns on, the fuel valve opens and heating occurs again.
The circulation pump forcibly moves the coolant in the system, which avoids freezing when the temperature drops. The speed of the pump can be adjusted.
The combustion products are discharged outside through the chimney, which is organized in accordance with the regulations and using only materials resistant to aggressive environments and high temperatures.
The diagram of the main components of the unit is shown below:
Benefits of a convection boiler:
- A wide range of designs and models allows you to choose a boiler for a large private house or a small apartment.
- Price categories are different, everyone can choose the unit that suits the cost.
- Wall and floor installation types.
- The radiator is made of cast iron, so it is designed for a long service life.
- Automatic sensors and sensors ensure safe operation.
- Settling on the walls, condensate contributes to corrosion. But in these models, more of it is discharged into the chimney pipe. The low residual condensate residue minimizes the risk of metal damage.
- The outdoor thermostat automatically adjusts the circuit heating temperature.
- Frost protection.
- Simple construction and operation.
Experts identify several disadvantages of convection-type boilers, but they can be challenged:
- Double-circuit devices are sensitive to water quality. On the one hand, this is an inconvenience. On the other hand, if you initially install filters, then in the future you will avoid the formation of scale, heating disturbances and combustion of the heat exchanger.
- Devices with a closed combustion chamber are volatile. Indeed, turbocharged models require a connection to the network, since the smoke exhaust fan is powered by electricity. If this problem is relevant for you, choose boilers with an open chamber.
Convector type boilers
A gas convector is a heating device that looks like an electric fireplace: it does not require connection to piping systems for heating. But structurally, it is similar to a boiler: inside there is a burner, a closed-type combustion chamber and exhaust gases. Smoke is removed through a special tube.
It is recommended to install the unit in the lower part of the room. The coldest air passes through the convective part, heats up and rises.
In such a device there is a fan, it quickly and efficiently distributes warm air throughout the apartment. The convector device is mounted in a permanent place. After that, a hole is made for the outlet of the chimney. Installation can be carried out independently.
Which is better: a gas boiler or a convector? For heating a dwelling, of course, a boiler is better suited. The convector quickly and unevenly heats the air, and after turning it off, the temperature quickly drops. Therefore, it is better to install such units in warehouses and industrial buildings.
Convection or condensation?
What is the difference between these two types of devices? Both run on gas fuel, provide hot water to radiators and hot water. However, the efficiency of one is over 90%, and the other – 107-110%. How is this possible? The condensation method makes it possible to use the latent heat of combustion products.
Carbon monoxide vapors contain acid and corrosive substances. In convection technology, they are diverted to the street, and in condensation technology they are cooled to the dew point (52-56 degrees). This technology was not possible until stainless steel was welded into production. Ordinary metal was quickly corroded by acid.
Modern products are equipped with an additional heat exchanger. Condensation occurs in it, which accumulates in the tank. As a result of the conversion of steam into liquid, additional (latent) energy is generated, which is transferred to the coolant. The principle of operation is similar to the economizer in steam boilers: it is used to increase efficiency due to the energy of combustion products. This device is installed in a separate room and takes up a lot of space.
Everything is relative. Condensing boiler:
- More economical and efficient, but the savings depend on the cost of fuel.
- Does not cool the air in the room, as it is taken from outside.
- It is applied in low-temperature systems, such as a “heat-insulated floor”.
- It needs a high-quality and reliable chimney that will withstand an aggressive environment.
In addition, you will have to think about how to remove accumulated moisture. If in apartments it is mixed with sewer water, then in a private house it is necessary to equip a separate sewerage system (for more details, see the publication “What is a condensing boiler”).
Convection heater:
- much cheaper than condensation models;
- equipped with a cast iron radiator;
- produces less condensate;
- consumes more fuel;
- models with an open combustion chamber take air from the room, so it cools faster.
Major faults
With each release, manufacturers improve their technology. But absolutely reliable devices have not yet been invented. Here are some of the problems users face:
- Small flame in the burner. This happens when the nozzles are clogged with dust and soot, or when the air content in the fuel is high.
- After ignition, the burner does not work or the flame goes out. The reason may be the lack of draft, blockage of the chimney, ionization electrode. Cleaning and replacement of faulty elements.
- Noise at work. The heat exchanger is overgrown with scale, so the water inside boils and makes noise. The radiator needs to be descaled.
- The device does not start. It is necessary to check the connection of the phase and zero, turn the plug in the outlet.
Self-diagnosis of the boiler reports problems with sensors and nodes. The display shows an error code. Its value indicates the cause of the failure.
There are problems that do not depend on the manufacturer and user, but affect the operation of the equipment:
- Line pressure drops. Many manufacturers produce equipment adapted to our realities. Such units can operate at a pressure of 1,5-2 bar.
- Incorrect installation, blockage of the chimney. Installation must be carried out strictly according to the regulations.
- Voltage interruptions. It is recommended to connect a stabilizer.
Consider the most popular models.
Varieties of convection equipment
Among the residents of apartments, mounted models are more popular. Floor options are more often mounted in private homes, in a separate room.
Vaillant turboTEC plus VUW 362/5-5
One of the smallest and most compact models. The device includes a “turbo” type burner and a closed gas exhaust system. Flame modulation is adjustable from 30 to 100%. Thus, you can not only adjust the heating temperature, but also save on fuel.
Smoke is removed through a coaxial pipe. The efficiency reaches 93%. A feature of the Vaillant turboTEC plus is the presence of two heat exchangers. The primary is made of copper for heating the coolant in the heating circuit. Secondary – stainless steel – provides hot water.
The built-in pump with regulation of speeds in three positions. The boiler safety system includes:
- expansion tank;
- bypass (provides constant circulation of the coolant);
- relief valve;
- protection against jamming and freezing.
Electronic ignition, as well as the control panel. The power of the product reaches 36 kW. Dimensions – 800x440x338 mm. The cost is from 67 rubles.
Ross Aogv 10 Pkd Sit Economy
Economical floor equipment consisting of two circuits. This boiler looks more like a fireplace, but it works much more efficiently, its power is 10,5 kW. The efficiency is 93%. There are two radiators in the design. One of them is made of steel; the second (lamellar) radiator is designed to provide domestic hot water.
The product is suitable for heating areas up to 105 m². Works when connected to the main line and cylinder. The system functions stably when the pressure drops to 1,5 bar. Built-in protection against overheating (thermostat), gas control. The circulation of the coolant is natural. The burner is started by piezo ignition. Dimensions – 610x650x280 mm. The price is from 19 rubles.
CTC 950 gas
This is a combined heater from a Swiss company. How is it different from AOGV? First of all, the price. This is one of the most expensive and reliable devices. In addition, dual-circuit equipment runs on two types of fuel: in winter it will be convenient to use diesel heating, and in summer you can turn on the gas supply to heat hot water. Boiler installation is allowed.
The rectangular structure is hung on the wall. Thermal power 30 kW, efficiency – 94%. Carbon monoxide is vented to the street through a coaxial pipe, and air is taken from there to maintain the flame. On the outer panel there is a large display and push-button control. Protective automation includes:
- thermostat – temperature control;
- safety valve – for fluid selection with increasing pressure;
- external thermometer;
- expansion tank 12 liters.
Dimensions – 690x900x370 mm. The cost is from 200 rubles.
Bosch Gas 7000 W
The equipment is suitable for heating apartments and houses 280-350 m². The double-circuit closed-type unit reaches 33,3 kW in power. Heating between the radiators and the DHW is almost instantaneous thanks to the flow sensor. Electronic control allows you to separately adjust the temperature and power for both circuits, which is important in the summer.
Burner with smooth flame modulation. To transfer to liquefied fuel, it is enough to put nozzles of the desired diameter.
Features of Gaz 7000W:
- installed draft sensors and thermostat;
- built-in frost protection;
- flame ionization;
- gas control;
- pressure valve;
- circulation pump with three modes and blocking protection;
- automatic ignition.
Dimensions – 480x825x370 mm. The price is from 50 rubles.
If you are faced with the choice of heating equipment, consider the advantages and disadvantages of convection boilers, as well as the type of housing and layout. Knowledge about the features of convection gas boilers will help you choose the right equipment and save money during its operation in the future.