A gas air heater is a device designed to heat the air in a room. Today, this device is widely used in livestock and poultry factories that require a certain temperature regime, however, today they are often used in residential buildings. The second unwritten name of this heating device- gas oven. It is worth noting that the air heater is powered by natural gas, which gives it the advantage of minimal inertia, from which the heat that has arisen from the burnt gas quickly spreads throughout the room, thereby heating the room in a short time. The rate of heating in a room is also affected by the power of the gas heat pump.
The air heater consists of several parts, this is a casing, a heat exchanger, a heat exchanger, a multi-speed fan and a smoke exhaust fan, gas valve, as well as a heat and noise insulator. The principle of operation is very simple.
Air is supplied to the heat exchanger through the fan, then, thanks to gas burner heats up and enters the heat exchanger, and only then enters the room and heats the room. Although the device generates carbon monoxide, it is not dangerous, because this gas leaves through a special chimney.
The choice of such an air heater today is not an easy task, because on the market heating technology there is a wide variety of models of gas ovens, differing in the principle of operation, functions and capacities.
First of all, you need to take into account the area of \u200b\u200bthe room. When choosing an air heater for rooms large sizes you should pay attention to devices with a power of 750 -2500 kW, and for a smaller square fit power and less than 750 kW.
It is also necessary to take into account the presence of gaps in doors, windows and walls, since there is a high probability of heat loss through them, which is directly related to saving money.
By the way, there are 2 classes of gas stoves, premium and economy, such air heaters differ in price and brand of the manufacturer. There are also economical thermal ovens, which can reduce up to 75% of the energy expended when heating a room. It is worth paying attention to the sound insulation of such an air heater, as excessive noise can bring discomfort.
The most efficient and economical of all air heating systems is gas. Because at the expense high efficiency thermal device, due to the low gas waste rate, the cash costs of installing such a system will pay off quickly. Even the absence of a central gas supply will not interfere with its use.
Summarizing, it should also be noted that gas air heaters are simple structures, and most importantly, reliable, which is so necessary on cold winter days in many industrial workshops and residential premises. By purchasing a gas air heater, you can confidently trust him not only with your business, but also with your home.
As soon as these products are not called - starting from fire heaters, heat guns, just burners and further: gas heaters, gas ovens, hot (warm) air generators, air heat generators. The most common (correct) name is still gas air heaters and, when viewed from the side of supply units, gas heating sections. This material is short review on a topic for ventilation and air conditioning professionals, for whom gas air heaters are still a novelty.
The main focus is on air handling units with gas heating air.
Direct fired gas air heaters
direct heating- this is the heating of air directly by the flame of the burner. Direct heating devices (also called mixing-type air heaters) do not have combustion chambers or heat exchangers.
Modern systems combustion allow highly efficient combustion of natural gas, however, when designing, it is necessary to calculate the dilution of hazards entering the room with combustion products below the MPC. These units are especially effective at high air exchange rates, when the level of hazards emitted indoors significantly exceeds the level of combustion products from direct-heated gas air heaters: foundries, welding shops, etc.
Thermal power range - 40-1500 (2000) kW.
Due to the lower metal consumption, mixing gas air heaters are cheaper than recuperative ones. Large range of power modulation. The absence of a chimney, the combustion products are immediately mixed with the heated air - there is no need to think about the condensate of combustion products when working with negative outdoor air temperatures.
Widely distributed in the USA, Canada, Great Britain. There are manufacturers in France, Germany and Holland. In Russia, they are still relatively rarely used, although we also have several domestic manufacturers.
Indirect gas air heaters (recuperative)
With indirect heating, the air supplied inside the unit by means of a fan is heated by passing around the combustion chamber and through the heat exchanger. The heated air is then discharged either directly into the room or supplied through a duct system. The products of combustion are removed through the chimney.
Devices indirect heating in turn, they are divided into air heaters with built-in atmospheric burner(with a tubular heat exchanger) (Fig. 2, 3, 4) and on heat exchange modules with an additional fan (inflatable, blast) burner.
circuit diagram units of the first type: an atmospheric burner at the inlet, i.e., operating under atmospheric pressure and consisting, as a rule, of several nozzles / nozzles (similar to those on any home gas stove). Further, after the tubular (plate) heat exchanger at the outlet, there is a smoke exhaust fan, thanks to which the combustion products pass through the heat exchanger.
Advantages— simple design, which means a competitive price.
Disadvantages:
small range of thermal power: 15-150 (200) kW. To provide more thermal power, these heat exchange modules are installed in series and / or in parallel, which leads to an increase in the cost of this solution;
difficulties, if necessary, to work in the mode of condensation of combustion products.
Schematic diagram of an air heater with a fan burner: a fan burner (i.e. with a fan) is installed in the combustion chamber of the heat exchange module. Due to the pressure created by the burner, the combustion products pass through the combustion chamber and heat exchange pipes (channels).
Thermal power range - 40-1000 (1200) kW. A more expensive solution compared to atmospheric burners corresponding in terms of thermal power, but on the other hand a larger power range, it is easier to solve the problem of the formation of condensate of combustion products - the possibility of using diesel burners.
Intermediate conclusion: at the moment, due to the small range of thermal power, it is advisable to use gas air heaters with an atmospheric burner for small air handling units or monoblock (roof top) air conditioners. For large central air conditioners and air handling units, gas air heaters (heat exchange modules) with an additional fan burner are more competitive. Further, in more detail about the version of the gas heating sections, consisting of a heat exchange module (air heater) and a fan (inflatable) burner.
Materials used to manufacture the heat exchange module
The heat exchange module for the fan burner conditionally consists of a combustion chamber and then a heat exchanger.
Most manufacturers use the following materials:
- The combustion chamber is made of stainless steel AISI 430 (GOST - 12X17) when working with air heated to a maximum of 120 ° C. For combustion chambers and various connections when air is heated to temperatures from 120 ° to 280/300 ° C and at a degree of air heating (dT) of more than 80 ° C, heat-resistant stainless steel AISI 310 (GOST - 20X23 H18) is used. Sometimes various pressures and air temperatures, different thicknesses of steel are used for combustion chambers.
- With the exception of condensation of combustion products inside the heat exchange module, the heat exchanger pipes can be made of carbon steel, for example, steel S235JR (GOST - St3 sp) or aluminized steel. In case of possible condensation of combustion products in the heat exchanger, it is necessary to purchase an air heater with a heat exchanger made of acid-resistant stainless steel: AISI 316 (GOST - 08X17 H13 M2), AISI 441 (no analogue in GOST according to DIN X2CrTiNb18), AISI 304 (GOST - 08X18 H10) and extreme case AISI 409 (no analogue in GOST according to DIN X2CrTi12), in which condensate drain must be provided.
The phenomenon of formation of condensate of combustion products directly in the heat exchange module itself is due to increased cooling of the latter. At a constant nominal air flow, this can be caused by a low supply air temperature or a decrease in the heat output of the burner below 60-65% of the nominal when operating on 100% recirculated air.
One of the ways to reduce the amount of flue gas condensate inside the heat exchange module is to organize a bypass line that operates depending on the temperature of the flue products in the chimney.
Fuel
The fuel for gas air heaters can be, firstly, liquefied petroleum or hydrocarbon gases (LHG): propane and butane. They are also called heavy hydrocarbons because, unlike natural gas, they are heavier than air. In case of leaks, they are more dangerous, since they do not evaporate, but spread along the floor, filling niches. It is a mixture of propane and butane that is sold for household needs in cylinders.
Liquefied carbon gases can be used by almost any burner when the nozzle is changed and reconfigured accordingly. However, due to the fact that LPG is not much cheaper than diesel fuel, for industrial facilities this is a very rare option.
Secondly, the fuel for the burners can be liquefied natural gas (LNG), i.e. liquefied methane. It is cheaper than LPG, but in Russia, with its developed network of gas pipelines, its use is exotic.
Finally, the third and most common option: natural gas is methane.
Gas pipelines for natural gas are divided into networks of low (up to 0.05 kgf/cm2), medium (from 0.05 to 3 kgf/cm2) and high (from 3 kgf/cm2) pressure.
Atmospheric burners and premix burners are designed for low - 20 mbar - inlet gas pressure; when connecting them to a gas pipeline, as a rule, additional reduction gears must be used.
The inlet pressure of fan burners (fig. 7) can be different depending on the gas train (multiblock) used (fig. 7). The lower limit depends on the characteristics of the ramp and the heat exchange module. The upper threshold for burners is usually fixed: 100, 360 or 500 mbar. Thus fan burners can operate in networks with low and medium pressure.
It should be said that diesel burners can also be included in the composition of gas heat generators. In addition, there are combination burners operating on both gas and diesel fuel. But such a solution is quite expensive, therefore, if necessary, a diesel burner is installed at the facilities, and then a gas burner is bought.
When using diesel burners, operation in the mode of condensation of combustion products should be avoided.
Gas and diesel fan burners, automation
Depending on the task of the burner, there can be:
Single-stage - operate at one fixed power;
Two-stage - operate at two pre-set power values (low and high);
Modulating - the power of its work can smoothly vary from min to max values.
The selection of the burner is carried out according to the power of the heat generator and the back pressure created in the combustion chamber; in addition, the length of the burner nozzle must be taken into account. The length of the burner nozzle must be within the range specified by the manufacturer of the heat exchange modules.
Air heaters (heat exchange modules) are equipped with a block of thermostats that provide the internal logic of operation and safety of the heating section, but do not control the temperature in the heated and/or ventilated room. Automation for controlling the temperature in the room (in the air duct) is a separate issue, depending on the task and the burner used.
Features of placement of air handling units with gas heating
The placement of air handling units with gas heating inside heated rooms is regulated by the document NPB 252-98 “Heat generating devices operating on various types fuel. Fire safety requirements.
If the air heater is placed in the ventilation chamber (Fig. 9), then here you should look at the norms of SNiP II 35-76 * "Boiler installations".
The simplest option in terms of approvals and normative documents- outdoor placement. At the same time, do not forget about outdoor service.
Standard European outdoor air heat generators (air heaters) are designed for operation at temperatures down to -15 (20) °С. Automatic burner allows it to turn on at a temperature not lower than -15 °C. Usually a burner and electrical shield just cover the top with a casing of sandwich panels (
In most cases, this is enough, since the burner heats both itself and the surrounding space during operation. There are examples when these measures allow the burner to serve normally in Russian conditions for more than one year.
On fig. 11 you can see an example of a more thorough execution of the gas air heater section: the section with the burner is insulated on all sides, grilles are made for ventilation of the section.
In regions where the temperature drops below -30 °C in winter, the burner section must be heated. Most often, for this, an additional electric heater, sometimes bring warm air from a heated room or ventilation duct.
The feasibility of using gas air heaters and the situation on the market
In general, a gas air heater (supply unit with a gas heating section) is more expensive in capital costs than a similar plant with water (electric) heating, but, on the other hand, a gas air heater is always cheaper than a boiler room + water supply unit of the same heat output.
Accordingly, gas air heaters are the most competitive when there is no parallel large boiler house (heating main), and a small boiler house is used, for example, for some small ABK (office center) and / or hot water supply
That is, on the basis of gas air heaters, one system air heating and ventilation: industrial premises, warehouse, shopping mall, cinema or gym. As a rule, in this case, in supply units (air heaters), mixing chambers are provided for simultaneous operation with supply and recirculated air. It is possible to heat and/or ventilate particularly fire hazardous premises by supplying superheated 100% supply air, but such installations are more expensive and complex. Initially, the main purpose of gas air heaters is air heating.
A gas air heater in the mode of a clean supply unit, which solves only the problem of ventilation, is used for rooms heated by gas infrared heaters (radiant heating) or hinged gas air heaters (gas air coolers).
Currently, there are several types of units with gas air heating on the market. The first type is floor air heat generators (gas air heaters). Such devices usually consist only of a heat exchange module and a fan section. The second is monoblock rooftop air conditioners(in English they are called Roof Top), which, in addition to the cooling section, may have a heating section on water, electricity or gas. Finally, the third - custom-made supply and air handling units with gas heating section.
It is clear that the use standard solutions- this is a lower capital cost, but sometimes the only acceptable option is custom-made installations, equipped, for example, with a recovery section, humidification and other additional equipment.
We consider this topic open. It is better to clarify some nuances for a specific task by contacting a specialized specialist.
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Recuperative air heater with atmospheric burner |
Gas heating section with atmospheric burner |
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Air heater with fan burner |
Heating section with bypass |
 Fan burner with gas train |
An example of an object with gas supply units |
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Execution of section under a torch at street placement |
After switching on the convectors and oil coolers, heat does not enter the room immediately. First, the case and the elements responsible for the accumulation of energy are heated. To quickly increase the temperature in spacious rooms, it is more advisable to use an infrared heater to heat the house. It works instantly, saving fuel.
Its radiation is similar to sunbeams. The difference lies in the absence of the ultraviolet component of the spectrum. Infrared waves pass through the air with almost no heating, 92% of the heat is transferred to solid surfaces, which are directed gas device. The temperature of objects depends on their color, material, shape and angle of incidence of the rays. From heated surfaces, secondary heat escapes into the air.
Main components: gas cylinder, reflector, regulator (reducer), heating element, enclosing and auxiliary components. According to the principle of work infrared heaters on natural gas for the home is divided into black and light. The former are used exclusively for heating, while the latter, in addition to their main functions, perform lighting. In both cases, the gas is supplied through the reducer to the burner. With direct heating, the oxygen supply for fuel combustion comes from the room, the exhaust air goes back. With indirect type of heating, a system for venting gases to the street is provided.
Options
Before choosing a gas ceramic heater, you should familiarize yourself with its main characteristics:
- Power. The optimal value is determined at the rate of 1 kW per 10 m2 of the room. The figure is increased if the house is poorly insulated. Often such gas infrared equipment has several degrees of power with the possibility of its adjustment.
- Wavelength - than more room, the shorter the radiation should be.
- Type of heating: direct or with removal of gases from the room.
- Moisture protection. Its level is usually indicated in the marking on the body, packaging or in accompanying documents.
- Installation method: floor, wall, ceiling.
- The presence of additional options: piezo ignition, control system and so on.
Overview of popular models
Roberts Gordon produces several varieties of gas-fired energy-saving heaters for the Blackheart restaurant and home: BH (single and double linear, U-shaped, multi-burner system), AG (linear low-intensity) and HE (dust and water tight). Infrared equipment is designed for installation on a wall or ceiling in a room of 90 - 600 m2, runs on liquefied or natural gas. Cost: 43,000 - 144,600 rubles.
Affordable prices for Timberk infrared heaters (2,500 - 5,500 rubles), compactness and ease of use have made them popular. Ceramic burner with 1 or 3 sections is switched on in series, the power is adjustable. There are infrared models with wheels for moving, with an internal gas cylinder lock and a special body structure that enhances the heat wave effect. The kit includes protective systems. Heating area - 30–65 m2.
Hyundai is a manufacturer of gas heaters HG1 Eruption, HG1 Voyage and HG1 Geiser, presented in various modifications. The last two series are equipped with piezoelectric ignition. Power range 1.4–4.2 kW, weight 2.5–9 kg. In reviews of Hyndai gas-fired heaters, consumers note ease of use due to compactness, a handle for moving, the ability to adjust power, tip-over protection and an oxygen concentration sensor. Cost: 2,400–8,500 rubles.
Neoclima presents indoor (UK-18C) and outdoor (09HW-B, HSS-RS-SS) gas heaters. Permissible fuels are LPG or propane/butane. A small weight of 13-18 kg allows you to freely move devices inside or outside the home. Fuel consumption by gas IR heater Neoclima UK-18C is 0.1–0.3 kg/h, at a power of 4.2 kW. All models are equipped with an emergency shutdown system. The price fluctuates between 3,900 and 11,000 rubles.
Elekon Power ТТ-15S (1.5 kg, 1.5–4.4 kW) and ТТ-30S (3 kg, 1.5–8.8 kW) are gas type heaters for rooms of 35–70 m2. Mounted on top of the cylinder without reducers and adapters. The output power is adjustable in three stages. Additional options: manual or piezo ignition, emergency shutdown of blue fuel supply. The average cost is 3,500 - 7,500 rubles.
Do-it-yourself design and installation
Correct installation of a gas-type heater in a house involves maintaining a certain distance (depending on power) from its body to a person’s head. For example, optimal distance for a device of 1–1.5 kW - 1 m. Also, do not direct infrared rays towards explosive, melting and releasing unpleasant odors surfaces and objects. The most elementary placement of floor-standing direct heating appliances is simply placed in the chosen place. If the design provides for a gas exhaust system, for safety it is better to call a specialist. Wall and ceiling models are fixed on special brackets.
You can independently make a heater from a conventional burner-nozzle on a gas cylinder. To do this, a mesh is installed on top of the device, which will dissipate heat. It is easiest to make it from an economic sieve. Fasteners for fixing are cut out of galvanized sheet according to the size of the mesh. As a holding material, metal squares (4 pcs) are used.
To enhance the characteristics of a gas IR heater, you will need metal grid. A blank-cylinder is cut out of it in diameter equal to, and in height 2 times greater than the sieve. Another fastener is made of galvanized metal with holes along the edges distributed over the entire diameter. The resulting cylinder is fixed on top of the sieve. The finished nozzle is put on a gas or collet cylinder using an adapter.
Advantages and disadvantages
Advantages:
- Uniform distribution of heat, several power levels.
- Fast heating of air without noise and a smell.
- The compactness of gas-type heaters with significant power.
- Profitability. Compared to heating boilers, fuel consumption is reduced by up to 50%. Thanks to the rational distribution of heated air, heat losses are reduced.
- Ease of installation, maintenance and operation.
- Independence from electricity.
- Possibility of heating large areas.
Disadvantages:
- During operation, some household heaters adversely affect the air. Regular ventilation is required. It is recommended to install a humidifier.
- Expensive repair and cost.
- Regular cleaning, checking, refueling and calibration is required. First of all, this item concerns infrared outdoor gas heaters.
Air heating systems
In a number of cases, it is possible to significantly reduce capital and operating costs by providing autonomous heating of premises with warm air based on the use of heat generators running on gas or liquid fuel. In such units, not water is heated, but air? fresh supply, recirculation or mixed. This method is especially effective for providing autonomous heating industrial premises, exhibition pavilions, workshops, garages, stations Maintenance, car washes, film studios, warehouses, public buildings, gyms, supermarkets, greenhouses, greenhouses, livestock complexes, poultry farms, etc. .
Advantages of air heating
There are many advantages of the air heating method over the traditional water heating method in large rooms, we list only the main ones:
1. Profitability.
Heat is produced directly in the heated room and is almost entirely consumed for its intended purpose. Thanks to the direct combustion of fuel without intermediate coolant high thermal efficiency of the entire heating system: 90-94% for recuperative heaters and almost 100% for direct heating systems. The use of programmable thermostats provides the possibility of additional savings from 5 to 25% of thermal energy due to the standby mode function automatic maintenance room temperature during non-working hours at the level of + 5-7ºС.
2. Ability to "turn on" supply ventilation. It's no secret that today in most enterprises the supply ventilation does not work properly, which significantly worsens the working conditions of people and affects labor productivity. Heat generators or direct heating systems heat the air by ∆t up to 90ºС, which is quite enough to "force" the supply ventilation to work even in the conditions of the Far North. Thus, air heating implies not only economic efficiency but also improving the environment and working conditions.
3. Small inertia. Units of air heating systems enter the operating mode in a matter of minutes, and due to the high air turnover, the room is completely warmed up in just a few hours. This makes it possible to quickly and flexibly maneuver when heat needs change.
4. No intermediate coolant allows you to abandon the construction and maintenance of a water heating system that is inefficient for large rooms, a boiler room, heating mains and a water treatment plant. Losses in heating mains and their repair are eliminated, which makes it possible to drastically reduce operating costs. AT winter time there is no risk of defrosting the heaters and the heating system in the event of a prolonged shutdown of the system. Cooling even to a deep "minus" does not lead to defrosting of the system.
5. High degree of automation allows you to generate exactly the amount of heat that is needed. Combined with high reliability gas equipment this significantly increases the safety of the heating system, and for its operation a minimum of service personnel.
6. Low cost. The method of heating large rooms with the help of heat generators is one of the cheapest and most quickly implemented. Capital costs for construction or renovation air system, as a rule, is significantly lower than the cost of organizing water or radiant heating. Payback period capital costs usually does not exceed one or two heating seasons. Depending on the tasks to be solved, heaters of various types can be used in air heating systems. In this article, we will consider only units operating without the use of an intermediate heat carrier, recuperative air heaters (with a heat exchanger and removal of combustion products to the outside) and direct air heating systems (gas mixing air heaters).
Recuperative air heaters
In units of this type, fuel mixed with the required amount of air is supplied by the burner to the combustion chamber. The resulting combustion products pass through a two- or three-way heat exchanger. The heat obtained during the combustion of the fuel is transferred to the heated air through the walls of the heat exchanger, and the flue gases are discharged through the chimney to the outside (Fig. 1), which is why they are called "indirect heating" heat generators. Recuperative air heaters can be used not only directly for heating, but also as part of a supply ventilation system, as well as for process air heating. The rated thermal power of such systems is from 3 kW to 2 MW. The heated air is supplied to the room through a built-in or remote blower, which makes it possible to use the units both for direct air heating with its delivery through louvered grilles, and with air ducts. Washing the combustion chamber and the heat exchanger, the air is heated and sent either directly to the heated room through the louvered air distribution grilles located in the upper part, or distributed through the air duct system. An automated block burner is located on the front of the heat generator (Fig. 2)
The heat exchangers of modern air heaters are usually made of stainless steel (heat-resistant steel firebox) and last from 5 to 25 years, after which they can be repaired or replaced. efficiency modern models reaches 90-96%. The main advantage of recuperative air heaters is their versatility. They can work on natural or liquefied gas, diesel fuel, oil, fuel oil or waste oil, you only need to change the burner. It is possible to work with fresh air, with an admixture of internal and in full recirculation mode. Such a system allows some liberties, for example, to change the flow of heated air, to redistribute heated air flows "on the go" to different branches of air ducts using special valves. In summer, recuperative air heaters can operate in ventilation mode. The units are mounted both in a vertical and horizontal position, on the floor, wall, or built into a sectional ventilation chamber as a heater section. Recuperative air heaters can even be used for heating rooms of a high comfort category, if the unit itself is moved outside the zone of direct service.
Main disadvantages:
1. Large and complex heat exchanger increases the cost and weight of the system compared to mixing type air heaters;
2. Need chimney and condensate drain.
Direct air heating systems
Modern technologies have made it possible to achieve such purity of natural gas combustion that it became possible not to divert combustion products "into the chimney", but to use them for direct air heating in supply ventilation systems. The gas supplied to combustion completely burns out in the stream of heated air and, mixing with it, gives it all the heat. This principle is implemented in a number of similar ramp burner designs in the USA, England, France and Russia and has been successfully used since the 1960s at many enterprises in Russia and abroad. Based on the principle of ultra-clean combustion of natural gas directly in the heated air flow, gas mixing air heaters of the STV type (STARVEINE "star wind") are produced with a rated thermal output from 150 kW to 21 MW. The technology of combustion organization itself, as well as a high degree of dilution of combustion products, make it possible to obtain clean warm air in the installations in accordance with all applicable standards, practically free of harmful impurities(no more than 30% MPC). STV air heaters (Fig. 3) consist of a modular burner unit located inside the housing (air duct section), a DUNGS gas line (Germany) and an automation system. The housing is usually equipped with a hermetic door for ease of maintenance. The burner block, depending on the required thermal power, is assembled from the required number of burner sections different configuration. Automatic heaters provide smooth automatic start according to the cyclogram, control of parameters safe work and the possibility of smooth regulation of thermal power (1:4), which allows you to automatically maintain required temperature air in the heated room.
Application of gas mixing air heaters
Their main purpose is direct heating of fresh supply air supplied to industrial premises for compensation exhaust ventilation and thereby improving the working conditions of people. For rooms with a high air exchange rate, it becomes expedient to combine the supply ventilation system and the heating system - in this regard, direct heating systems have no competitors in terms of price / quality ratio. Gas mixing air heaters are designed for:
Autonomous air heating of premises for various purposes with a large air exchange (K 1.5);
air heating in air-thermal curtains of a cut-off type, it is possible to combine it with heating and supply ventilation systems;
pre-heating systems for car engines in unheated parking lots;
heating and defrosting of wagons, tanks, cars, bulk materials, heating and drying products before painting or other types of processing;
direct heating atmospheric air or drying agent various installations technological heating and drying, for example, drying of grain, grass, paper, textiles, wood; applications in painting and drying booths after painting, etc.
Accommodation
Mixing heaters can be built into the air ducts of supply ventilation systems and thermal curtains, into the air ducts of drying plants both in horizontal and vertical sections. Can be mounted on the floor or platform, under the ceiling or on the wall. As a rule, they are placed in supply and ventilation chambers, but they can also be installed directly in a heated room (according to the category). With additional equipment, the corresponding elements can serve rooms of categories A and B. Recirculation of indoor air through mixing air heaters is undesirable, a significant decrease in the oxygen level in the room is possible.
Strengths direct heating systems
Simplicity and reliability, low cost and efficiency, the ability to heat up to high temperatures, high degree of automation, smooth regulation, do not need a chimney device. Direct heating is the most economical way - System efficiency equal to 99.96%. The level of specific capital costs for a heating system based on a direct heating unit combined with forced ventilation is the lowest with the highest degree of automation. Air heaters of all types are equipped with a safety and control automation system that provides smooth start, maintaining the heating mode and shutting down in case of emergencies. In order to save energy, it is possible to equip air heaters with automatic control taking into account external and internal temperature control, functions of daily and weekly heating programming modes. It is also possible to switch on the parameters of a heating system consisting of many heating units, into the system of centralized control and dispatching. In this case, the operator-dispatcher will have operational information about the operation and status of the heating units, clearly displayed on the computer monitor, as well as control the mode of their operation directly from the remote control room.
Mobile heat generators and heat guns
Designed for temporary use - at construction sites, for heating during off-season periods, technological heating. Mobile heat generators and heat guns run on propane (liquefied bottled gas), diesel fuel or kerosene. Can be both direct heating, and with removal of products of combustion.
Types of autonomous air heating systems
For autonomous heat supply various premises various types of air heating systems are used - with centralized heat distribution and decentralized; systems operating entirely on the supply of fresh air, or with full / partial recirculation of internal air. In decentralized air heating systems, heating and air circulation in the room are carried out by autonomous heat generators located in various sections or work areas - on the floor, wall and under the roof. The air from the heaters is supplied directly to working area premises. Sometimes, for better distribution of heat flows, heat generators are equipped with small (local) air duct systems. For units in this design, the minimum power of the fan motor is typical, so decentralized systems are more economical in terms of power consumption. It is also possible to use air-thermal curtains as part of an air heating system or supply ventilation. The possibility of local regulation and use of heat generators as needed by zones, at different times, makes it possible to significantly reduce fuel costs. However, the capital cost of implementing this method is somewhat higher. In systems with centralized heat distribution, air-heating units are used; The warm air produced by them enters the working areas through the duct system. The units, as a rule, are built into existing ventilation chambers, but it is possible to place them directly in the heated room on the floor or on the site.
Application and placement, selection of equipment
Each of the types of the above heating units has its undeniable advantages. And no ready recipe, in which case which of them is more appropriate, it depends on many factors: the amount of air exchange in relation to the amount of heat loss, the category of the room, the presence free space to accommodate equipment, from financial possibilities. We will try to form the most general principles for the appropriate selection of equipment.
1. Heating systems for rooms with little air exchange (air exchange ≤0.5-1)
The total heat output of the heat generators in this case is assumed to be almost equal to the amount of heat required to compensate for the heat loss of the room, the ventilation is relatively small, so it is advisable to use a heating system based on heat generators of indirect heating with full or partial recirculation of the indoor air of the room. Ventilation in such rooms can be natural or mixed with outdoor air to recirculate. In the second case, the power of the heaters is increased by an amount sufficient to heat the fresh supply air. Such a heating system can be local, with floor or wall heat generators. If it is impossible to place the unit in a heated room or when organizing maintenance of several rooms, a centralized type system can be used: the heat generators are located in the ventilation chamber (an extension, on the mezzanine, in the adjacent room), and the heat is distributed through the air ducts. During working hours, heat generators can operate in partial recirculation mode, simultaneously heating the mixed supply air, during non-working hours, some of them can be turned off, and the rest can be switched to an economical standby mode of + 2-5ºС with full recirculation.
2. Heating systems for rooms with a large air exchange rate, constantly in need of supplying large volumes of fresh air supply (Air exchange > 2)
In this case, the amount of heat required to heat the supply air may already be several times greater than the amount of heat required to compensate for heat losses. Here, it is most expedient and economical to combine an air heating system with a supply ventilation system. The heating system can be built on the basis of direct air heating installations, or on the basis of the use of recuperative heat generators in a design with a higher degree of heating. The total heat output of the heaters must be equal to the sum of the heat demand for supply air heating and the heat required to compensate for heat losses. In direct heating systems, 100% of the outdoor air is heated, ensuring the supply of the required volume of supply air. During working hours, they heat the air from outside to the design temperature of + 16-40ºС (taking into account overheating to ensure heat loss compensation). In order to save money during non-working hours, you can turn off part of the heaters to reduce the supply air flow, and switch the rest to the standby mode of maintaining + 2-5ºС. Recuperative heat generators in standby mode make it possible to provide additional savings by switching them to full recirculation mode. The lowest capital costs in the organization of centralized heating systems when using the largest possible heaters. Capital costs for STV gas mixing air heaters can range from 300 to 600 rubles/kW of installed heat output.
3. Combined systems air heating
The best option for rooms with significant air exchange during working hours with a one-shift operation, or an intermittent work cycle - when the difference in the need for supply of fresh air and heat during the day is significant. In this case, it is advisable to separate the operation of two systems: standby heating and forced ventilation combined with a heating (reheating) system. At the same time, recuperative heat generators are installed in the heated room or in the ventilation chambers to maintain only the standby mode with full recirculation (at the calculated outdoor temperature). The supply ventilation system, combined with the heating system, provides heating of the required volume of fresh supply air up to + 16-30ºС and preheating of the room to the required operating temperature, and for economy purposes it is switched on only during working hours. It is built either on the basis of recuperative heat generators (with an increased degree of heating), or on the basis of powerful direct heating systems (which is 2-4 times cheaper). Possible combination supply system reheating with the existing hot water heating system (may remain on duty), the option is also applicable for staged modernization existing system heating and ventilation. With this method, operating costs will be the lowest. Thus, using air heaters various types in various combinations, it is possible to solve both problems at the same time - both heating and supply ventilation. There are a lot of examples of the use of air heating systems and the possibilities of their combination are extremely diverse. In each case, it is necessary to carry out thermal calculations, take into account all the conditions of use and perform several options for selecting equipment, comparing them in terms of feasibility, capital costs and operating costs.
GAS AIR HEATERS
PKA-N
GAS AIR HEATERS
PKA, PKE, AH systems
Popular Models
Sonniger is a manufacturer of fan heaters, air curtains, ventilation systems and supplier to the domestic market. Products manufactured by our engineers have passed quality control by European experts and fully comply with Russian standards safety and quality. They are useful and efficient devices that will reliably protect the building from the cold and provide fresh air to any facility, both industrial and commercial.
Floor gas air heaters RK
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Floor standing gas heaters PKare used for heating and ventilation of rooms for various purposes. Air heaters PK are produced in versions with condensing effect (K series) and without condensing effect (N series); in addition, they can be designed for installation inside a heated room (RCA) assembled with a heat exchanger, ventilation unit and an electrical panel for installation indoors or in a protected place, as well as for installation outside (PKE) complete with heat exchanger, ventilation unit, electrical panel and burner compartment, being intended for installation outside the premises. PK Benefits:
Static pressure options:
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Burners for gas supply units To complete gas air heaters, burners operating on:
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dimensions
- PKE-N
Additional features
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1.Anti-vibration connection 2.P fire damper 3.Regulating damper for air intake 4.Damper connection kit 5.Servo motor for damper 6.Manually th damper actuator 7.Filter block 8.R e guiding device for two-stage th burners 9.Inverter for capacity/air pressure adjustment 10.Burner 11.Rain grille 12.Mixing block 13.Channel transition 14.Channel Elbow 15.Air Distribution Plenum 16.T temperature probe for duct 17.Flow control damper 18.Three way connection 90 °
for 19.Condensate collection pipe 20.Elbow 90° for chimney 21.Smoke intake module 22.Straight th chimney long th 1m 23.Chimney terminal (umbrella) 24.Anchor bolt kit for 25.Chimney clamp 26.Temperature probe in 27.Flow control damper |
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Air handling units with gas air heating from Sonniger
Air heaters are widely used in Moscow at modern enterprises and warehouse facilities. These are very efficient devices that can provide heat even to the largest areas. In addition, this technique can be used not only for the purpose of heating, but also for the ventilation of rooms and the removal of harmful and corrosive gases and fumes.
In my own way appearance these devices are thermally insulated panels made of 2 sheets (internal and external) of stainless steel with thermal insulation inside, a functional heat exchanger made of stainless steel AISI 430, AISI 441, as well as a ventilation section with NICOTRA/GEBHARDT driving fans, the main task of which is to suck in air for further processing and supply inside the premises. Initially, it may seem that gas supply units are complex devices, but this is not so, since every consumer will be able to use such equipment. Having ordered such heat generators, you will no longer have to return to the issue of providing your facility with comfortable working conditions, since these installations will perfectly cope with the mission assigned to them.
Order gas heat generators in Moscow
Turning to Sonniger, a company with a wealthy practical experience in this area, the customer will be able to obtain the full amount of information regarding the operational characteristics of such equipment, its functionality, scope, etc. The staff of our company is represented by recognized specialists whose qualifications will leave you no doubt about the competence and professionalism of our company, and the quality installations will exceed even the highest expectations.
The work process of this heating equipment proceeds as follows. With ventilation sections Fresh air enters the heat generator, where it heats up to the set temperature, passing through the combustion chamber and heat exchanger. After that, it is fed into the room. gas heater air is equipped with a chimney through which the products of combustion are discharged into the atmosphere.
We are always ready to offer customers a reasonable price level and stable high quality. Therefore, do not waste time looking for cheaper and less effective devices, the operational life of which is not very long. Having ordered a gas heat generator from us, you will forget about the issue of heating your facility for a very long period, enjoying comfortable conditions for productive work.
