Low-power gas boiler 5 kW - operating conditions

The heating system in a house consists of several elements, the most important of which is the heating boiler. This section contains models that use natural gas as an energy source. Gas heating boilers are widely popular due to the availability of this type of fuel. The Tavago online store offers an assortment of hundreds of models, among which there are suitable options for a private home, apartment or industrial premises, public, commercial facilities and buildings.

Low power application

Heating equipment with reduced performance, running on natural or liquefied gas, is designed to maintain comfortable air temperature in apartments up to 100 m². Due to possible heat losses (for example, through the walls of a house or window openings), it is recommended to take into account a correction factor that reduces the size of the serviced room by 15-20%. Since the design does not include electronics, the heaters can be used in buildings not connected to AC power.

When using a 5 kW gas boiler, the following conditions must be met:

• high-quality insulation of walls, flooring and ceilings;
• no gaps between window frames, door frames and load-bearing surfaces;
• the height of the premises should not exceed 2.7 m;
• the house should not be located in a climate zone with prolonged frosts below -15°C.

Small-sized gas-type heating systems are easy to operate and configure.
The small size of the heat exchanger has a positive effect on fuel consumption and efficiency. Disadvantages of the equipment include a limited selection of models and the lack of additional functions. Boilers produced by small Chinese companies are equipped with original design elements, which makes repairing the equipment difficult.

Criterias of choice

Now that we’ve sorted out the basic concepts, it’s time to voice additional criteria that will help evaluate the ease of use of the models you’re interested in and add individuality to them.

External insulation available. It is the external thermal insulation that makes it possible to reduce heat loss when warming the boiler room and significantly slows down the cooling time of the boiler. This also allows you to load the firebox no earlier than after 7-12 hours, eliminating the need for “cold” kindling.

The number of elbows in the smoke exhaust system. If the boiler chimney is straight, its performance is equal to the efficiency of a small indoor fireplace. The more economical the heating device becomes, the more parts the chimney is made of.

Pressurization system. The presence of such a unit reduces the requirements for the number of chimney bends. At the same time, a boiler with high efficiency copes well with the process, even with clearly weak draft. Devices with a pressurized design require constant monitoring of the furnace door seals; the presence of the most inconspicuous gap guarantees the entry of smoke into the living areas of the house.

Which manufacturers produce 3 kW boilers?

The main manufacturers of gas household equipment for heating water:

1. Vaillant (Germany) offers ecoVIT series equipment equipped with a gas supply intensity regulator. For example, the rated power of the VKK INT 226-476/4 installation is 22 kW, but the user can manually reduce the parameter to 5 kW. The installation diagram contains electronic control units that require power supply.
2. The German concern Bosch assembles boilers and flow-through heaters, but the productivity of the equipment produced is above 3 kW. A similar situation is observed with the products of the Swedish company Electrolux, which are not intended for use in homes without electricity supply.
3. De Dietrich factories produce heaters with a power of 20 kW or more; the performance is reduced manually. The design includes electronics that receive power from household AC power.
4. The Russian Lemax plant offers several models of gas single-circuit boilers with a capacity of 6 to 8 kW. Products are installed on floor coverings or attached to the wall surface. The advantage of heaters is the absence of electronic units that require power supply.
5. The product line of the Italian company Beretta includes the Exclusive Green 16RSI boiler with a minimum thermal output of 3.5 kW (manually adjusted). The unit is equipped with an electric pump and a system of safety elements; to ensure operation, it must be connected to a 220 V network.
6. The Slovak plant Protherm offers wall-mounted and floor-mounted gas installations. The performance of boilers equipped with electronics exceeds 20 kW; power reduction is achieved by reducing the degree of heating of the coolant.
7. Heaters of the AOGV series are assembled by various enterprises in the Russian Federation using Chinese components (for example, Borinskoye OJSC). The design of the heaters does not include electric ignition units or flame modulation controllers. The boilers are mounted on floor coverings; the design is designed for unstable gas and water pressure.

If the home owner wants to use equipment with reduced performance, it is recommended to choose electric boilers or units that burn solid fuel (wood or coal).

For example, the Zota company offers pellet-type boilers with a power of 10 kW or more, which are used for heating industrial facilities or residential buildings. Electric water heaters from the manufacturers “Resurs” or “Rusnit” are not equipped with a built-in pump and are used to provide hot water supply.

Floor models

The Premium 7.5 unit, developed by Lemax, belongs to the category of single-circuit non-volatile equipment. The boiler is connected to centralized gas supply lines, and the possibility of using liquefied fuel is provided. The design includes brackets for installing an indirect boiler that supplies heated water to the mixers. The standard heat exchanger is made of steel sheet 2 mm thick, connected by resistance welding. The surface is covered with heat-resistant enamel, which prevents corrosion of elements.

The gas is atomized by a small-sized burner from the Italian manufacturer Polidoro; the line is equipped with a SIT safety valve, which allows pressure drops in the pipeline. The design does not contain electrically controlled elements; the boiler can be used in places with unstable power supply.

To ignite the fuel, a piezoelectric element is used, which is activated when the button is pressed. At the bottom of the housing there are ventilation windows that supply heated air into the room.

The Lemax plant offers a 6-kilowatt AOGV unit of the Gazovik series, used for organizing heating in residential buildings. Under the heat exchanger there is an open combustion chamber, air is supplied from the room. Hot gases pass through the radiator and are then released into the atmosphere through a channel with a diameter of 112 mm. The temperature of the combustion products does not fall below 110°C, the manufacturer claims an efficiency of 87%. The installation has a height of 680 mm, weight is 35 kg, the design does not provide for connecting an additional boiler.

Another representative is the Russian-made 8 kW floor-standing gas boiler HotSpot ECO KSts-G-8S. To heat the coolant, a steel heat exchanger is used, equipped with protection against temperature rise. The manufacturer claims an efficiency of 92% and a service life without major repairs. The cylindrical radiator has increased strength; the heater can be used in a closed heating system with forced circulation (the pump must be purchased separately).

Wall boilers

The Patriot-6 installation from Lemax with a power of 7.5 kW of convection type belongs to the category of parapet systems. The unit is mounted on the wall surface, exhaust gases are discharged into the atmosphere through a coaxial channel. The device can operate in heating systems with natural and forced circulation of coolant; switching to a 220 V electrical network is not required. To heat the liquid, a radiator made of 2 mm thick alloy steel, coated with a layer of heat-resistant enamel to protect against corrosive processes, is used.

A closed combustion chamber with a small-sized injection burner is mounted inside the housing; a piezo ignition unit is used to ignite the gas. The manufacturer has provided for the installation of a safety valve that shuts off the fuel supply channel when the oxidation process stops.

The fluid supply circuit has a thermal fuse and a traction control sensor. If the air supply is interrupted, the burner automatically turns off. A ventilation grille is provided in the lower front part of the casing to heat the room.

The Exclusive Green 16RSI product has a thermal power of 3.5 kW. The boiler is equipped with a radiator that serves the heating system in a residential building. The manufacturer recommends using the unit in rooms up to 160 m²; the design provides the possibility of installing an indirect heating boiler for hot water supply. The standard burner is designed to use natural gas; when switching to liquefied fuel, the nozzles must be replaced. The boiler is characterized by the use of a closed combustion chamber with forced air supply.

The Baxi ECO 4s 10F unit (rated heat output 10 kW) is equipped with a copper radiator and a stainless steel burner. An exhaust fan is installed that continues to remove combustion products after the gas supply is turned off. A Grundfos pump with a filter that separates air bubbles is used to circulate the liquid. A three-way valve installed in the boiler allows you to organize hot water supply. The secondary heat exchanger is heated by the flow of liquid used in the heating circuit.

Is it possible to install a gas boiler of less than 5 kW indoors?

What are the minimum gas boilers? The building is about 30 sq. meters (+/- 5 sq.). And on the Internet I found at least 7 kW. Is there less or not? At least 5 kW?

Anton

Expert answer

Hello, Anton.

The fact is that among domestic gas boilers there are indeed very few units with a power of less than 7 kW. Most likely, the low popularity of low-power heating devices is explained by the geographical location of our country and the mentality of our compatriots. You need to look towards manufacturers in Europe or neighboring countries - their product line includes many reliable and inexpensive heating devices with a power of 5 kW, sufficient to heat an area of ​​up to 50 square meters. m. Offhand, I literally immediately managed to find a good parapet-type ThermoBar KS-GS-5-S boiler with excellent automation from EuroSit.

If for one reason or another the options you are looking for do not satisfy you, then feel free to take a more powerful unit with a modulating burner. With little demand, the modulation mode will reduce the boiler power to the required value. At the same time, the amplitude of changes in gas supply states directly affects the control range, so devices with deep burner modulation would be the preferred option. Many branded units have such abilities. Of course, in comparison with domestic heat generators they have a higher price, but this disadvantage is offset by expanded functionality and increased service life.

• Author: Victor Kaploukhiy
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Conclusion

Gas heaters with a power of 3 to 5 kW are distinguished by the absence of electronics, which allows the equipment to be used in village houses. The owner can use a standard boiler with a single or double circuit, but to reduce fuel consumption it is necessary to reduce the heating performance. The units are equipped with electronic flame modulation units and control panels with a display; to ensure operation, they require a connection to the electrical network and a chimney to remove combustion products.

Advantages and disadvantages

Boilers with a power of 5 kW have pros and cons.

Advantages:

• compactness and light weight, which allows the units to be installed in any room, and a separate boiler room is not needed;
• affordable price;
• reliability and safety without electronic control systems;
• ease of installation and operation;
• no need to install a traditional chimney;
• relatively low gas consumption with high efficiency.

Such devices also have disadvantages, which include limited functionality, small selection and strict requirements for operating conditions.