Diesel heat gun direct and indirect heating: device, principle of operation + manufacturers review

Alexey Dedyulin
Checked by a specialist: Alexey Dedyulin
Author: Yana Mokeeva
Last update: March 2019

With the onset of cold weather, it is necessary to solve the heating problem not only in houses and apartments, but also for various industrial premises, construction sites, garages, warehouses, hangars and other non-residential objects.

And one of the options for heating appliances that attracts consumers at an affordable price and mobility is a diesel heat gun. Therefore, we consider in more detail the principle of operation of this device, the scope of its application and the main selection criteria.

Design differences of diesel guns

The main purpose of heat guns is fast and economical heating of rooms with a large area. They work on diesel fuel, during the combustion of which heat is released, which spreads through the object with a directed air stream.

By the constructive principle, all diesel guns can be divided into devices for direct and indirect heating.

Direct heat generators

The main structural elements of a diesel gun: an electric motor with a fan, a pump with cleaning filters, a combustion chamber, a spark generator (glow plug or high-voltage system), a nozzle and a fuel tank.

In order for the device to work autonomously, it is equipped with a timer, a flame level controller, a thermostat and other electronic elements that can be built-in immediately or installed for a fee.

Direct heating diesel gun
With direct heating, diesel combustion products also get into the hot air stream, therefore, such a heater can only be used in non-residential premises with good supply ventilation

The direct heating unit works like this:

  • When the device is turned on, fuel is pumped from the tank to the fuel filter using a pump.
  • Then the fuel enters the nozzle, and it injects it into the combustion chamber.
  • The ignition system delivers a spark that ignites a diesel engine.
  • A protective net installed in the "muzzle" of the gun holds fire, preventing it from leaving the combustion chamber.
  • The fan drives cold air into the chamber, where it heats up from burning fuel and is brought out by a warm stream.

Direct heating guns have a high level of efficiency - almost 100%, the air temperature at the outlet can reach 400 ° C.

Such heat generators can have a power of 10 to 220 kW (depending on the model), which all goes to heat.

Comparison of direct and indirect heating guns
For work in the open air or in a large room without thermal insulation, direct-heating heat guns are chosen, and for indirect buildings where people are located, indirect units are better suited

But since an unpleasant smell, soot and other combustion products of diesel fuel penetrate into the air with heat, the scope of the device without a chimney is limited to sparsely populated production rooms, open areas and various warehouses.

They are also widely used in construction, for example, for drying facades and concrete screed during plastering or facing.

Indirect Heaters

The design of guns with indirect heating provides for the presence of a closed combustion chamber and chimney, with which exhausts with fuel exhaust are removed outside the heated room.

Although the maximum power of such devices reaches a maximum of 85 kW, there are complex modular units with several "gun barrels" that can reach up to 220 kW.

The principle of operation of the indirect heating gun
Despite the presence of a chimney, indirect heating guns also require good ventilation and ventilation, because oxygen burns out during their operation

Although the efficiency of such units is much lower (approximately 60%), they are not only suitable for all cases where direct-flow devices can be used, but are also widely used for heating livestock farms, greenhouses, non-residential buildings, exhibition halls, production facilities and other premises with prolonged presence of humans or animals.

Advantages and disadvantages of diesel equipment

Although the modern market offers a fairly wide selection of heating appliances, diesel guns do not lose popularity among consumers.

After all, despite the fact that the cost of similar gas and electric units are much lower, the operation of diesel devices is much cheaper due to the affordable price of a diesel engine.

Diesel gun for heating the warehouse
In many guns, you can use not only DT, but also other fuel, for example, diesel fuel, kerosene or filtered oil, but this point needs to be clarified when buying

The advantages of a diesel heat generator include:

  • High efficiency - even taking into account airing and supply ventilation the device quickly warms up the air and spreads it throughout the room.
  • Easy operation - to start the system, it is enough to direct the "barrel" of the gun at the center of the room or building element and press the power button.
  • Safety - Modern devices are equipped with various sensors and temperature regulators, thanks to which the device itself does not overheat. Accidental flame attenuation is also excluded, and when the air is heated to a predetermined temperature, the gun temporarily stops working.
  • Low cost of fuel - even devices demanding the quality of diesel fuel will be much more profitable in operation than electric or gas devices.
  • Convenience in transportation - the heat generator is compact and light enough (a simple device with a power of 10-22 kW weighs about 11-13 kg), so there will be no problem to bring it to an object or move it from one room to another.
  • Cost-effectiveness - a small amount is required to heat the room fuel, and the device can work for a long time without refueling. For example, a direct heating unit of 22 kW and a tank volume of 20 liters consumes on average about 2.5 liters per hour of operation.
  • Long life provide wear-resistant materials, standard replaceable components and simplicity of the design itself.

Of course, not without flaws.In addition to harmful evaporations of diesel fuel, the problem of which can be solved with the help of a chimney or a well-functioning ventilation system, the minuses of the device include the need to connect to the power grid, noise during fan operation and fuel level control.

In addition, the cost of the gun itself and its repair will be higher than that of similar devices running on gas or electricity.

The basics of choosing diesel heat generators

As with other heating appliances, the heating rate and the size of the area that the heat gun can cover depend on its power. But in addition to this important characteristic, there are other nuances, the knowledge of which will help you make the best choice when buying a device.

Determining the required power of the device

Not only fuel consumption, but also the heating rate depends on the power of the heat gun. And although all the technical specifications are indicated in the accompanying documentation for the unit, before buying it is worthwhile to estimate the volume and availability of thermal insulation in the room, which is planned to be heated using a diesel heat generator.

Calculation of thermal power
On average, a small 10 kW gun can warm up to 100 m2 with a ceiling height of no more than 2.5 meters, but for more accurate calculations you can use the special formula

Find out the thermal power of the device by the following algorithm:

  1. Calculate the volume of the room in m3, multiplying the values ​​of its width, length and height in meters.
  2. Determine the difference between outdoor temperature and required for the room.
  3. Multiply the volume with the temperature difference and the heat loss coefficient.
  4. And the last stage is to convert the value from kcal / hour to the usual kW. To do this, you need to divide the resulting figure by 860.

The value of the coefficient will depend on the materials of which the building is built, and the level of its thermal insulation:

  • “Cold” structures made of wood or metal will have an indicator of 3 to 4;
  • buildings with minimal insulation, laying in one brick and a primitive roof structure - from 2 to 2.9;
  • buildings with average thermal insulation with double masonry, standard roofing and a small glazing area - from 1 to 1.9;
  • rooms with double-glazed windows, double brickwork, insulated walls and a roof - 0.6-0.9.

Let's check the operation of the algorithm in practice. For example, you want to heat a metal hangar to +18 ° C, an area of ​​150 squares and a height of 4 meters. The average outdoor temperature in winter is 10 degrees below zero.


(150 m2 * 4 m) * 28 ° С * 4 = 67200 kcal / h: 860 = 78.14 kW

That is, when choosing a model of a heat gun, you should focus on devices with a capacity of 80 kW and above.

The ratio of the area of ​​the room and the power of the heater
To estimate the power of the device, you can use the data from the table, which shows the relationship between the characteristics of the heat generators and different volumes of buildings, taking into account the temperature difference of 30 ° C

But the fuel consumption indicator, although it seems an important parameter, is actually quite arbitrary. Indeed, regardless of its technical capabilities, the device will require as much fuel as is needed to heat a particular building, based on the temperature you set, the volume of the room, and the quality of thermal insulation.

Other important nuances

When you have decided on the most important parameters (power and heating method), you should pay attention to other characteristics.

For example, such a nuance as the form at first glance seems to be exclusively a “matter of taste”, especially since almost all guns have the appearance of an elongated cylinder. But it is better to choose rectangular units from high power devices - they have a larger distribution area of ​​the warmed air flow.

Diesel thermal module
A rectangular gun with several nozzles will allow you to quickly process a large amount of air, therefore it is widely used for drying materials in construction and organizing heating for several rooms at once

Other technical features:

  1. Case insulation - the surface temperature of the device itself during operation should not exceed 40 degrees.
  2. Mobility - it is convenient when the device is equipped with a wheelbase, but lightweight guns with a power of up to 22 kW can be mounted simply on a stable base. In this case, pay attention to the weight of the kit, the material and strength of the pallet.
  3. Noisiness - the more powerful the fan of the device, the louder the “musical accompaniment” will be during its operation.
  4. The ability to adjust the temperature - the device should be equipped with a knob or button with which you can independently program the thermostat parameters.
  5. Battery operation - if the object is not connected to the mains, you can pick up a gun that works from the drive. The electricity consumption of the device is low (basically, power is required for the fan), varies between 100-500 W / h, so even a car battery is enough for uninterrupted operation for several hours in the field.

Also, when buying, you should inquire about the presence of a protective system against overheating (some manufacturers offer it as a separate device). For safe operation, it is desirable that the gun be equipped with automatic control of the heating level and off when there is insufficient fuel.

Direct Diesel Gun Operation
For direct heating guns, it is forbidden to use fuel such as fuel oil, alcohol, acetone and gasoline, which can damage the unit, provoke a fire or explosion of fuel vapors

The type and parameters of the recommended fuel is another important nuance that should be checked with the seller of the equipment. For most diesel guns, it is recommended to use clarified (aviation) kerosene or “winter” automobile DT that meets GOST 305-82.

If it is not possible to purchase a heat gun, then you can make it yourself. And what is required for this, read Further.

Startup and safe operation rules

Typically, appliances are shipped partially disassembled. That is, it will be necessary to fix the "barrel" of the gun on a wheeled cart and install a handle (or metal arcs). If we are talking about a direct heating gun, it remains only to refuel the fuel tank, plug the device into the mains, set the heating temperature and press the power switch.

Diesel gun device
Thanks to the built-in thermostat, the gun will automatically stop working when the air warms up, and will turn on again when the temperature drops - this way the device saves fuel and eliminates the possibility of overheating

To start the equipment, make sure that the following safety rules are observed:

  1. The gun is mounted on a stable and even horizontal surface made of non-combustible materials, such as concrete. If the floor is wooden, you can put sheet metal under the unit.
  2. The distance from the nozzle from which the flow of hot air will come to the nearest object is at least 2 meters (it is advisable to keep a distance of 80-100 cm to the right and left).
  3. Before starting up for the first time or after long periods of storage, it is recommended that you open the case and manually turn the fan wheel to make sure it rotates freely.
  4. The device will “signal” the need for refueling with intermittent burning or the emission of white smoke. To add fuel, be sure to disconnect the gun from the mains.
  5. Always turn off the gun with the toggle switch and wait for the fan to stop completely. For devices with indirect heating, this process can take 2-5 minutes, but it is necessary for cooling the combustion chamber. Only then can the plug of the appliance be pulled out of the network.

To start the indirect heating diesel gun, you must first mount a chimney - a round pipe made of non-combustible material with a maximum length of 3 meters. If you need a long-distance lead, for this purpose it is convenient to use a flexible aluminum corrugation, but it will have to be changed several times during the heating season.

For removal into closely located ventilation, you can find a piece of steel pipe, which will last much longer.

Indirect heating gun chimney
The path of the chimney for an indirect heating gun must be laid in a straight line, only one bend up to 90 degrees is maximum permissible

As for maintenance, for trouble-free operation of diesel heat generators, it will be necessary to periodically rinse the air filters and clean the combustion chamber of soot / dust. It is also important to monitor the cleanliness of the internal walls of the unit in the area of ​​the nozzle and engine.

Overview of heat gun manufacturers

The market of industrial heaters offers a wide range of direct and indirect heating guns operating on diesel fuel. But in order to buy a reliable heat generator and subsequently not have problems with its maintenance and replacement of worn parts, you should focus not only on price and technical parameters, but also on time-tested brands.

For example, Master Climate Solutions is one of the recognized leaders in the HVAC market. Thanks to a wide production and dealer network, it is possible to find diesel heat guns of indirect and direct heating from Master in almost any city and large construction store.

Diesel gun Master B 35
The direct-flow device Master B 35 with a capacity of 20 kW and a fuel tank of 15 liters is an excellent option for servicing small warehouses, hangars, greenhouses

Thermal units Master work on diesel fuel, diesel fuel or refined kerosene, they are distinguished by high-quality assembly and compact dimensions.

Power ranges from 10 kW for simple direct-heating guns to 220 kW for heating plants with multiple nozzles.

Diesel heating system Master BV 460 E
For fast heating of large-volume rooms it is convenient to use powerful diesel heat generators that can direct several streams of warm air, for example, the Master BV 460 E heating system

Ballu diesel guns from the Italian brand Biemmedue have also proved to be quite good (although in the line the manufacturer more often you can see already traditional China). Their units are well protected from the cold and, thanks to the preliminary heating of the fuel, can be used even in frosts down to -30 ° C.

The designers paid special attention to the protection system - the case of the device is made of stainless steel and practically does not heat up even in the most powerful plants.

Gun of direct heating Ballu BHDP-20
One of the top models of the direct heating gun line is Ballu BHDP-20, which was highly appreciated by consumers for their good power, automatic control of the heating temperature and a multi-level security system

South Korean units from Tiger King and Kerona are also popular. Their diesel guns are equipped with high-quality electronic "stuffing" - thermostats, which guarantee protection against overheating and economical fuel consumption, an informative display, a photoelectronic sensor that controls the operation of ignition, and other nice additions.

Diesel gun TK-70000
Diesel heat guns from Korean manufacturers are perfectly adapted to Russian realities - low temperatures and power outages, and some models can also work on battery power, for example, like the TK-70,000 with a power of 65 kW

Heat generating units from other foreign brands have also earned good reviews from consumers - Elitech, Firman, Kroll, Oklima, Daewoo, HYUNDAI, Patriot.

If you prefer domestic products, pay attention to the ProfTeplo, Interskol and Zubr diesel guns.

Conclusions and useful video on the topic

To get a visual representation of the device of the device itself, its operational capabilities and selection rules, we suggest that you familiarize yourself with the following videos.

The roller provides a detailed overview of the indirect heating gun Master BV 77 E with technical characteristics and measurements of the air temperature at the outlet of the device:

The tips and the formula for calculating the required power of a heat gun for heating rooms of various types are presented in the video:

The video explains in detail how thermal diesel guns work, their varieties are available, and application features for various rooms are indicated:

Due to its high power and efficiency, diesel heat guns occupy a leading position among industrial heat generators. And although the device is not cheap, its price will pay off during operation.

Therefore, if you need to organize fast and economical heating of rooms, a diesel gun is a good choice. However, you can always consult with specialists who will advise both the method of heating and the optimal model of the heater.

If you have any questions when reading this information or have recommendations for our readers, please leave your comments in the box below. There you can share the experience of using diesel guns.


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Visitors Comments
  1. Sanya

    Good thing there are reviews. They may come in handy soon. There is such a “baby” in our warehouse. Served honestly for several years. Manufacturer Daewoo. Great brand. Heated quickly, economical. Recently, the fan has stopped working in the on position. With the thermostat, everything is fine. We tried to regulate it - the result is zero. Who had this? What could it be?

  2. Nikolay

    Good deal. Two of these were put into the warehouse, and in winter they normally heat the entire room, goods do not deteriorate from humidity and cold. At the same time, we leave the windows on airing, we are not afraid of fire, one watchman checks every couple of hours, and everything is in order. For the money it turns out fine, lower than if electric heaters worked, what can we say about our own generator.

  3. Pavel

    Concerning the Ballu BHDP-20 gun. China from 08.2019. The case is NOT made of stainless steel, but only painting and galvanizing. Riveted combustion chamber. There is no preliminary heating of the fuel.

    There is no declared and advertised COOLING function of the combustion chamber after turning OFF the gun. I disassembled the gun in detail and did not find any structural or electronic elements to implement the very useful COOLING function after stopping.
    Otherwise, this is a NORMAL gun on parts from China and made in China. I do not recommend overpaying for the BALLU brand!