Schematic diagram of a gas convector with forced air and flue gas removal. The installed fan heater speeds up the process of heat exchange and reduces the warm-up time of the room
Scheme of the Gazelle Techno Premix convector from FONDITAL with a complete premix burner and a system for maintaining a constant air / gas ratio
Gazelle Techno heaters from FONDITAL have a side air humidifier…
Piping is carried out only outside the house according to the project
The gas pipeline is fastened with clamps with a rubber gasket
Windscreen at the end of the flue
Economy class convector of the Emax GWH series from ELEKTHERMAX
If properly installed, the condensate that forms at the end of the flue will drain to the ground.
A shut-off valve is installed at the “inlet” in front of each device.
Option to connect the device to the gas line. View with decorative cover removed
Scheme of burner operation with full premixing
Gas instantaneous water heaters and boilers, electric convectors and water heating radiators- all this equipment, well known to anyone who has ever faced the problem of providing heat to their country house. Now devices have appeared on the market that, according to the principle of operation, resemble a traditional gas water heater. But they do not heat the water, but the air in the room itself. We are talking about gas convectors.
Closed combustion cycle
If gas convectors have been widely used for many years in the countries of the USA and Europe (including Scandinavia), then for Europe this is a relatively new, still unfamiliar type of equipment. However, the number of products of different brands imported to our market is increasing year by year. So the problem of choice is quite solvable (if it exists at all). Now in specialized stores you can buy heating gas appliances manufactured by FASER (Poland), ELEKTHERMAX, FEG KONVEKTOR (Hungary), FONDITAL, FRACCARO, ROBUR (Italy), BAXI GROUP (Great Britain) andetc. In Europe, similar equipment is manufactured by the KONVEKTOR plant (Europe).Uzhgorod).
Such products are optimal in terms of price-quality ratio among operational heating devices, that is, used, for example, in country houses with a non-permanent mode of residence. If you need heat in the workshop, sauna, utility room, gas convectors- one of the most efficient ways of generating heat, since it does not require the installation of a boiler, circulation pumps, piping, risers and other expensive components of the central heating system. Moreover, you can turn on the convector exactly at the time when you need it.- in the off-season, in early spring or autumn and, of course, in cool rainy summers.
This appliance provides space heating by means of hot air convection. According to its basic structure, it is quite simple: it consists of a decorative removable casing in which the heat exchanger is located. This is where combustion of the incoming gas takes place. Heat is transferred from the outer surface of the heat exchanger to the circulating room air. The device itself is mounted on the wall according to the attached template. The casing is removable, which facilitates the maintenance of the device and routine maintenance. The material from which the heat exchanger is made can be different: for FASER and ELEKTHERMAX it is sheet steel coated with heat-resistant enamel paint; at ROBUR and FONDITAL- Aluminium alloy; at BAXI- cast iron.
Since the burner flame and the combustion chamber itself are completely isolated by the walls of the heat exchanger and are not in direct contact with the air of the room in which the convector is installed, the possibility of burnt gases entering the heated room is completely excluded. The intake of fresh air necessary for gas combustion, and, accordingly, the removal of combustion products is carried out outside the heated living space. For these purposes, a coaxial (coaxial) flue, arranged according to the “pipe in pipe” principle, is led out from the back panel of the convector through the outer wall of the house. Thus, flue gases are removed through the inner pipe, and combustion air is taken in through the outer pipe. Both processes proceed due to natural draft, which occurs due to the difference in the density of the combustion products and the cold air entering the device. Since the pipes are located one inside the other, already heated air enters the combustion zone, which optimizes the formation of the gas-air mixture, contributing to a more complete combustion of the fuel.
The intake of air for combustion and the ejection of combustion products are also forced. ATin this case, the gas convector is equipped with a centrifugal fan, and the air intake and exhaust ducts can have separate pipes (such are some models from ROBUR, FRACCARO, FONDITAL). FROMon the outer side, on the wall of the building, the gas duct is closed with a decorative wind-protective grille, and as a result, the whole structure protrudes above the plane of the facade by 50–120mm (depending on model).
In principle, the operation of the convector does not require a connection to the mains: the ignition of the pilot burner is carried out using a piezoelectric element. True, there are models with electronic ignition. Such devices need power supply (
Since the convector heat exchanger has a developed finning, the whole structure is characterized by low thermal inertia and provides relatively fast heating of the air in the room. This, by the way, is especially convenient for intermittent operation, if you need convectors as a heat source, for example, only on weekends in the country.
The power level of the device can be adjusted, depending on the model, in steps or smoothly. BUTfor maintaining the desired air temperature in the range from 10 to 30
The main safety element in convection gas appliances is a system that automatically stops the gas supply in the absence of a flame. Moreover, the remains of the gas-air mixture are removed from the combustion chamber outside, outside the premises. This system includes a flame control unit that generates a signal that controls the gas valve, starting or stopping the gas supply. ATThe inexpensive models Emax GWH by ELEKTHERMAX, OGK‑F by FASER, the Puch FRE series by FRACCARO are usually fitted with a mechanical thermocouple assembly. More expensive devices (Puch FRO10 series from FRACCARO, Gazelle Techno Premix from FONDITAL, Supercromo from ROBUR) are equipped with electronic ionization flame control.
In models with forced draft, for example in the convectors of the Gazelle Techno Condensing series from FONDITAL and Supercromo from ROBUR, the output of combustion gases is also controlled. For these purposes, a safety air pressure switch is provided in the design of the device: in the event of a failure in the supply of combustion air or a malfunction of the air duct fan, the differential mechanism of the pressure sensor closes the gas valve and, therefore, stops the fuel flow to the burner.
In emergency situations (disappearance of the flame, difficulty in ejection of combustion products, and finally, the absence of air flow due to the overlap of the windproof cap), the automation switches off the device, stopping the fuel supply. The same happens in the case of a drop in gas pressure at the inlet to the device below the maximum allowable level. That’s just the minimum threshold value of gas pressure in the supply line, at which the convector turns off, is different for different manufacturers. Most Western European instruments are designed to operate at an inlet pressure of 20 mbar. Alas, in our gas pipeline networks, especially in rural areas, this figure can vary greatly, dropping to 8–10 mbar (in winter). Therefore, when choosing a heater, ask the seller at what minimum pressure the convector you have chosen is capable of operating. For example, for models of the Brazilia family from BAXI, “working capacity” is maintained when the gas pressure drops to 5 mbar, for convectors from Eastern Europe (FASER, ELEKTHERMAX)- up to 12 mbar, for Italian from FRACCARO- up to 18 mbar. Of course, with reduced pressure in the line, the power of the device will be no more than 70–80% of the nominal. This circumstance must be taken into account when choosing a convector.
When purchasing the necessary device, one should proceed from the calculation: 120W per 1m2 with a ceiling height of up to 3 m (with insufficient thermal insulation of the room). For example: a device with a power of 2.5 kW heats a country house with an area of about 18–20m2. You can not discount the number of windows in the room, as well as what materials the house is built from. After all, it’s one thing- a brick cottage, a building made of aerated concrete blocks and something completely different- panel house building.
For the operation of the device, both network (methane) and bottled liquefied gas (propane / butane) can be used. Most models are already configured for a particular type of fuel. True, if you want to switch from main fuel to gas from a cylinder (or vice versa), you simply cannot connect another source. The fact is that each type of fuel has its own standard size of nozzles of the main and pilot burners.
Make sure that the nozzles are always set to the gas pressure that is available in the gas pipeline connected directly to your home, or to the consumption of liquefied gas. When powered from the line, nozzles of a larger diameter are used for the main and pilot burners than when connecting a cylinder. Despite the fact that manufacturers necessarily indicate fuel consumption rates when operating their devices on mains or liquefied gas, the actual consumption is determined by the gas pressure in front of the main burner and the adjustable nozzle flow area.
You can reorient the device to another power supply if you additionally purchase the appropriate set of nozzles. Some companies (for example, ROBUR, BAXI) provide replacement kits for both main and liquefied gas already in the basic configuration. Essentially, replacing nozzles is no more difficult than swapping burners on a gas stove. But for reliability, it is still better to entrust this operation to a specialist.
If the convector runs on liquefied fuel, it must be taken into account that the source of liquefied gas must be located in the immediate vicinity of the convector, at a distance of no more than 4 m.otherwise, the pressure may not be sufficient for the heater to reach the nominal power mode.
The most familiar place in the house, where, as a rule, equipment that uses gas is placed (geyser, stove or oven),It is, of course, the kitchen. Take at least an ordinary stove: combustion products enter directly into the room, and in this case it is impossible to do without arranging ventilation ducts, hoods, trimmings in doors or vents that would provide fresh air. Approximately the same measures are taken when installing a gas boiler, say, in a room specially designated for it.- boiler room.
With convectors, the situation is different. Their owners do not have to organize additional ventilation in any special way, since the combustion process in the device (it is worth emphasizing again!) Has a closed cycle. Usually, a coaxial flue pipe and a wind protection grille are supplied with the convector. So there is no need for residents to inhale harmful combustion products and get up in the morning with a headache. Let’s get straight to the point here. Quite often, convectors are confused with gas fireplaces. BUTHere, fireplaces just use the air taken directly from the room in which they are located to maintain combustion.
Of course, each method of heating a house has its advantages and disadvantages. For example, electrical systems have an increased energy intensity, so that, despite the minimal initial costs for their arrangement, electric heating will cost several times more annually than heat from a main gas boiler house. FROMthis point of view, the independence of most models of convectors from the power supply- great advantage. Another advantage of this solution- the absence of a water circuit in gas appliances. By burning gas, you immediately heat the air in the room. BUTthis means that you do not need to deal with the freezing of pipelines and drain the coolant in anticipation of winter frosts, if the house is inhabited periodically. No surprises simply can arise: there is no coolant- there is no problem of its freezing, and the probability of damage to the heating system is reduced to zero. In addition, the gas heating system allows you to raise the temperature in the room to a comfortable level (25–30
And we have gas in the apartment …
All gas convectors on the European market today are quite definitely divided into two large groups, depending on the price and the combination of consumer characteristics.
The families of heaters of the series Emax GWH from ELEKTHERMAX, OGK‑F from FASER, Brazilia from BAXI, TS 2000 from ROBUR, as well as Uzhgorod convectors “AKOG” can be classified as economy class models. The cost of products varies from $230 to $400, power rating range- from 1.5 to 6 kW. Devices of this class are quite simple in design, since the basic equipment mainly provides for mechanical control and protection units. The flame is controlled by a thermocouple and the pilot burner is ignited by means of a piezo ignition. Therefore, the devices are completely autonomous, absolutely not needing to be connected to the mains. Such, for example, is the OGK‑F series of convectors, which includes 4 modifications with power from 1.8 to 5 kW. The devices are equipped with burners from the Italian WORGAS and protective automatics from JUNKERS (Germany). The Hungarian company ELEKTHERMAX produces its own burners for its heaters, and the protection unit (gas valve) is installed by the Italian company SIT. ATThe Emax GWH series has 4 models of different power ranging from 2.5 to 5.8 kW.
A wide range of convectors with power from 1.5 to 2.3 kW is presented in the Brazilia F5 and F5S series of economy class models from BAXI GROUP. The English firm focuses on well-thought-out design. ATin particular, the front panels have different colors (straw or grey-blue); the grille, located in the upper part of the body, is made of chrome. Moreover, you can choose a model with side panels stylized as oak or mahogany. A heater in this design will not spoil even a sophisticated interior.
In price category $400–800 presents more complex equipment with electronic control units, devices for maintaining room humidity and a forced air circulation system. You can find convectors “armed” quite seriously: pressurized burners with full pre-mixing of gas and air, electronic ignition, ionization control of the presence of a flame, etc. Models with electronic ignition, by the way, are more economical, since there is no need for an ignition burner with a constantly burning pilot flame.
On our market, products of this class are represented by products from FRACCARO, FONDITAL, ROBUR. ATThe program of different manufacturers includes models with power ratings up to 7–8 kW. Now FONDITAL convectors with a capacity of 2.5 kW (models 2200, 2200VT and 2200VT E), as well as 3, 5 and 7 kW (Premix and Classic) are on sale. ATROBUR’s SuperCromo range includes 8 positions, starting from the SC 3001 convector (2.3 kW) and ending with the SC 8002 model with a power of 7 kW. The Frev family from FRACCARO combines 5 models, and if the “younger” has a power of 2.5 kW, then the “older”- 8.2 kW.
Equipment of the highest price category is expensive enough to be used in a small country house, but is quite acceptable as the main heating system in country cottages with a permanent residence regime. The whole question is, on the model with what equipment to choose. After all, comfort, efficiency and ease of control of the device during operation (and the service life of convectors- at least 10–15 years)The circumstances themselves are important. Tofor example, the Puch FRO10 (FRACCARO) convector with a power of 4 kW and a cost of $The 650 can be programmed with a built-in timer to turn on or off depending on the time of day. ATThe standard equipment of the heater includes a double solenoid valve with a gas pressure regulator, an ignition electrode, an ionization flame control, an electronic room thermostat and even a filter to suppress radio interference. The design is also complemented by two fans- centrifugal (works on the forced removal of combustion products) and tangential. The latter has an electronic regulator and provides forced circulation of air masses in the room, thereby increasing the speed of hot air outlet. At the same time, a 3.4 kW convector installed in a room with an area of 20m2 (ceiling height- up to 3 m), heats the air from 0 to 20
The Gazelle Techno family of convectors from FONDITAL also has models with a convection fan heater, electronic automation and a function for programming operating modes. Feature of some FONDITAL convectors- in automatic control of power levels depending on the heat demand of the room. By monitoring the temperature in the room, the device, at the command of the microprocessor, can switch from reduced power (low mode) to maximum power (high mode) and vice versa. Thus, the set temperature is maintained by the convector independently, without human intervention.
The weakest point of all automatic systems- in need of connection to the power supply network. ATotherwise the electronics will not work. ATEuropean conditions, when the power supply is often absent or intermittent, the attitude towards devices that need to be connected to the electrical network is ambiguous. How will automation work during a power outage? Of course, in some models, the gas supply will immediately stop (security systems provide for such a situation). But will it make you feel warmer? For these reasons, and also due to high prices, more complex models of convectors are not yet very popular on our market. But economy-class devices with the most simplified control system and the simplest automation, completely independent of the vagaries of the power supply, are in great demand.
In heaters Brazilia from BAXI, Emax GWH from ELEKTHERMAX, Gazelle Techno Classic from FONDITAL and others, the processes of fresh air entering the combustion chamber and flue gas removal occur due to natural draft. Such convectors are equipped with an atmospheric ejector burner, to which a gas jet is supplied through a nozzle, entraining a stream of primary air. Thus, the gas-air mixture is formed immediately before the “entrance” to the main gas burner. At the outlet of the nozzle (already directly in the burner zone), an additional, or secondary, portion of air enters the resulting mixture, after which ignition occurs and a flame is formed. This principle of operation allows the device to work stably at low gas pressure.
The second group includes convectors, in which forced air and removal of combustion products are provided thanks to the installed centrifugal fan. ATas a result, the time for the device to reach the specified thermal regime is reduced. Devices of this kind are in the Gazelle Techno Premix models from FONDITAL, Supercromo from ROBUR, Frev from FRACCARO.
The Gazelle Techno Condensing convector from FONDITAL is equipped with a pre-mix burner: all the air necessary for combustion is mixed inside it, and the gas / air ratio is kept constant. Such a device makes it possible to ensure the completeness of fuel combustion with a small flame length, which means that the convector can be made more compact, with high efficiency. In addition, due to pre-mixing, the amount of harmful substances (nitrogen oxide and dioxide) in the exhaust of the device is reduced, which means that the environmentally harmful burden on the environment is reduced.
Convectors with natural draft, depending on the rated power, are designed for the installation of a coaxial flue of a certain length (from 200mm for devices manufactured by ELEKTHERMAX, FASER) and diameter (50–130mm). Models equipped with pressurization have a certain advantage in this sense, since the diameter of the coaxial gas duct can be smaller (50–80mm), which means that the windproof terminal will become an inconspicuous detail on the facade of the house.
There are models in which the air intake and chimney are separated. Thus, most FONDITAL pressurized appliances can be installed on walls that do not communicate with the outside, using elbows and pipe extensions (two diameters- 35 and 60mm). You can even extend the exhaust gas channel to the roof of the building. The permissible length of flue pipes depends on the model of the convector (its power), their own diameter, the number of corner joints throughout the entire gas flue path and is calculated for each specific case.
Let’s pick up a calculator, a pencil and calculate the approximate cost of operating a gas convector running on liquefied bottled gas, say, somewhere in the world region.
Filling a 50-liter cylinder in the world region will cost about 300rub. Gas consumption during convector operation by 2.5kW in rated power mode is approximately 0.2kg/h This means that a 50-liter cylinder will provide 114–125 hours of continuous operation. Considering that the convector does not work constantly, but is switched on periodically, maintaining the set air temperature in the room, the cylinder will last for about 20–50 days (it all depends on the outside temperature). The fact that the filling of cylinders is carried out not too accurately, “by weight”, taking into account the mass of condensate, also makes its own adjustments. With permanent residence in the winter, the operation of the same convector, but using natural main gas as fuel, costs about 370–4,5 dollars. ATyear (at the current tariff in the world region of 0.73 rub/m3). It consumes about 500–600m3 gas per year.
If your country house has already installed, say, a double-circuit gas boiler, whose “duty” includes heating water for both the heating system and sanitary needs, then gas convectors can become an effective means of heating in annexes (on a covered terrace or in attic), in utility rooms (garage, pantry, barn, etc.) or where there is a high risk of freezing of water heating pipes.
In principle, the cost of 1 kW of heat from a gas convector depends on the cost of installation work, the price of a particular model of the device and the cost of piping. You can calculate this indicator in a simplified way by dividing the cost of the convector by the indicator of its rated power and adding the amount spent on installing the heater itself. ATIn the case of our example, the installation cost of one kilowatt of heat will be about $120.
Three bold steps to warmth
When you buy a heater powered by bottled gas, it is enough to stock up on permission from the State Fire Supervision Service. FROMgas equipment on the main fuel (boilers, boilers, radiators and convectors), the situation is much more complicated. Be prepared for the fact that you will need to go through a whole series of bureaucratic procedures. Drawing up technical documentation and its coordination in various economic and administrative instances takes time, nerves, and money. The desired warmth will become available if you successively go through the three stages listed below:
one. Contact the territorial gas utility that serves the area where your house is located with a written statement about the desire to install a gas convector in your home. Tothe application must attach documents provided by the local BTI (plan-scheme of the premises, papers confirming your right to own the house).
2. Get technical conditions from the gas trust, on the basis of which you will order a project that determines the wiring diagram and the diameter of gas pipes, as well as the installation locations of convectors, etc. True, in some gas facilities you may be told that they have never heard of such a device, like a convector. ATIn this case, it makes sense to contact a company that specializes in the supply and installation of gas equipment. There you can also find out the coordinates of specialized organizations in which, for a fee (usually $70–90) can undertake all the necessary design work. As a rule, the project is ready in a maximum of a week.
3. The finished project must be coordinated with your local gas utility, so you will have to go to this institution again. And only after the “Agreed” stamp appears on your papers, you can proceed directly to the installation of all the necessary equipment and the gas pipeline.
The cost of installation work varies depending on the type of building (wood, brick, sandwich panels, etc.). The most expensive piece of work- making holes. For the installation of one convector, as they say, on a turnkey basis, you will be charged about $50–70. Not too expensive, given that this amount includes not only the cost of direct installation, but also the setup and testing of the device itself. Together with piping work, the cost of installing one heat point can reach up to $150.
The combustion process is inherently- This is a fuel oxidation reaction in which chemical compounds are released into the atmosphere in the form of flue gases, and a certain amount of heat. The combustion of gas in the convector, as a rule, occurs with an excess of atmospheric air. And as a result, the nitrogen present in the air (it is present in the combustion zone) also forms harmful compounds.- nitric oxide and nitrogen dioxide. In addition, the flue gases contain carbon monoxide and carbon dioxide and water vapor. ATAs a result, this turns into weakly acidic pollution of the area.
The problem of reducing the content of nitric oxide can be solved only by high-quality mixing of gas and air immediately before combustion. ATIf there is not enough air, carbon monoxide is formed as a result of incomplete combustion. True, combustion products do not enter the room where the heater is installed. And the air in your area will not be gassed- convectors themselves are much “cleaner” than an ordinary gas stove. When preparing the material, we were able to obtain information on the mass of harmful emissions only for convectors from FONDITAL. ATIn particular, the Gazelle Techno Premix and Condensing models, in terms of the limiting concentration of nitrogen oxides in flue gases, are included, according to European standards, in the fifth class of devices (up to 100 mg / (kW
When the products of gas combustion are cooled to the dew point, condensate falls out of them. Even if the sellers will assure you otherwise, you should not take a word. The laws of physics are the same for boilers and gas convectors. ATmodels, the coaxial flue of which passes directly through the wall of the house, the formation of condensate is possible after stopping or turning on the device (water will simply drip from the chimney to the ground and will not fall on the facade of the house). Since the flue gas temperature is about 120
|Item of expenses
|Approximate cost, $
|1. Equipment and materials
|Gas convector for 2.5kW (produced in Eastern Europe) with a set of coaxial pipes
|Cylinder (50 l) with valve
|Steel pipe (3/4″), 8m
|Flexible piping (50cm)
|TOTAL by materials
|2. Installation and commissioning
|Installation and configuration of the convector
|Installation of gas wiring
|Transportation costs (up to 30 km from MKAD)
The editors would like to thank the companies TEPLOIMPORT, SANI-CONSULTANT, FRAMOSS, as well as the European representative office of BAXI GROUP for their help in preparing the material.