Heat gun review: stock heat

When you need to heat a large room in a short time, call for help “heavy artillery”, t. e. heat guns. The main area of their application – construction works heating and process drying , maintaining a comfortable temperature in unheated homes, warehouses, local heating in the work outside, use in greenhouses and hothouses. You can also use such equipment in everyday life – permanently, or as a supplement to the main source of heating.

Heat in the warehouse

A GUN IN A CUT

In our country, where, as we know, the temperature conditions are not the most forgiving, we often have to resort to the “climatic weapon. One of its fast and powerful types is a heat gun. This technique is able to set a comfortable temperature in the room in a matter of minutes. You do not need to wait for it to warm up, as in the case of some more conventional heating devices, because the gun immediately begins to supply a stream of warm air. In addition, the guns are characterized by mobility, they can be moved from one place to another. These, by the way, are the features that largely determine the popularity of this technique.

Like conventional heaters, the gun consists of a heating element, housing and a fan. Only the fan here is much more powerful than a domestic fan: without it the heating of the room in such a short time would be impossible. That is what makes the air flow through the heating element, creating a powerful heat flow.

Most types of heat guns actually resemble a gun – the body is cylindrical, located horizontally or at a slight upward angle. There are varieties of other forms, which are mostly referred to as guns “for company”, usually it is a rectangular electric heaters. The body has other features. It is made of metal, that is quite logical, taking into account the high working temperatures inside the appliance. In addition, the metal protection mechanism is needed if the guns are used on a construction site or an industrial facility and that is where most guns and involved . Equipped with housing and thermal insulation.

YOU WILL NOT CALCULATE FOR US?

Before buying a heat gun, the future user must answer a few questions for himself beforehand. In what room will the heater work, what is its meterage and features purpose, thermal insulation ? Will there be people in the warehouse all the time?? What kind of fuel suits the user best – electricity, gas, diesel??.. Any good seller of heating equipment will ask such questions, so it is not superfluous to know the answers in advance. They will determine the approximate range of models that are suitable for the tasks required by the user.

For example, the volume of the room. Need to consider the performance of the gun. Calculate this figure can be based on the fact that one “issued” kilowatt is enough to heat about 8-12 m3 at an average ceiling height of 3 m. Accordingly, the larger the room, the more powerful the equipment must be.

As a matter of fact, there are formulas that can be used to calculate the necessary heat output. For example, Vx&Delta TxK = kcal/h, where V – volume of heated space WxDxH , m3 &Delta T – difference between outdoor temperature and desired indoor temperature, °C K – dissipation factor depends on the type of construction and insulation of the room . The coefficients are as follows: K = 3.0 – 4.0 – simplified wood construction or corrugated metal sheet construction, no thermal insulation K = 2.0 – 2.9 – simplified building construction, single brickwork, simplified window and roof construction, little thermal insulation K = 1.0 – 1.9 – standard construction, double brickwork, small number of windows, standard roof, medium insulation K = 0.6 – 0.9 – improved construction, brick walls with double insulation, small number of windows with twin frames, thick floor base, roof of high-quality thermal insulation material, high thermal insulation. 1 kW – is 860 kcal/h.

However, it must be remembered that any theoretical calculations do not give a completely accurate result, as much depends on the circumstances. Say, with very high ceilings in the rooms, experts advise to look at infrared heaters, they are also called longwave or radiant heaters, which do not heat the air, and the surface of objects, the heat from which is then transferred to the air.

To choose correctly a heat gun, other parameters are no less important. Each one has a different “personality.”. Depending on the method of heating the air flow, this technique is divided into several types: electric, diesel and gas guns. Each type has its own characteristics and advantages.

ELECTRIC HEAT GUNS

The simplest way to heat a room is to use the source of energy that can be found almost everywhere – electricity. Electric heat guns, which are often called heaters, are very popular today both in homes and in construction. They are extremely mobile and easy to use, do not require additional fuel, because they operate from the network: models up to 5 kW – from 220 V, those that are more powerful – from 380 V.

When passing current through a conductor with high resistance, heat is released, it remains only to bring it to its destination – to “blow” off the heating element with the help of a fan. In the role of such an element on the small power devices can be used open nichrome wire, wound in a spiral. Now most heat guns use heating elements – heaters that have a wire placed inside a tube. The tube is made of austenitic or non-austenitic steel. The latter heat less incandescent do not get red , so they are more durable, but carry a smaller heat load per unit area.

That is, for a comparable heating, you have to use longer heating elements. Another “minus” of using austenitic steels – during the process the stainless steel becomes brittle, microcracks appear, and the thickness becomes smaller as a result of oxidation. In addition to reducing the resource, this can lead to the risk of “explosion” of heating elements as a result of thermal expansion of the filler. In addition, the dark teens give a much smaller “oxygen-burning” effect.

Electric guns are small in size. For one thing, it’s convenient – it doesn’t take a lot of space. On the other hand, it limits their performance. Moreover, they are not suitable for heating premises where water can get on the gun and its heating element baths, saunas, etc. . p. . The fact that the gun works from the mains, many users will surely like it – no need to deal with either gas cylinders or filling the machine with diesel fuel. However, you should be prepared for high power consumption. It is quite noticeable, so most often the electric models are used for short term.

GAS HEAT GUNS

These models themselves weigh and cost inexpensive. Their capacity is usually in the range of 10-100 kW, but there are more productive models. The only problem – fuel. Liquefied gas is available at some gas stations, but not everywhere. Gas cylinders need to be constantly filled and have a place to store them. Making a large stock of gas is unlikely to succeed also because of the storage of gas cylinders has a number of requirements.

On the other hand, gas guns are economical, and the combustion of gas emits almost no harmful substances – only carbon dioxide and water. Therefore, during their work to ventilate the room can not be too often, but ventilation is still necessary, at least to replenish oxygen.

Some varieties of guns use mains gas for heating. It loses portability, but reduces costs and does not require reconnection of gas cylinders.

Regardless of what kind of gas works on the heating tool, you must remember that the pressure in the main line or cylinder must meet the requirements of the chosen model of heater. For the simplest of them with capacity of 10 kW you need pressure of not less than 0.5 bar. Accordingly, the more powerful the gun, the greater this parameter, and this should be taken into account before buying a heater, otherwise the technique simply will not be able to function.

For safety, many models of gas heaters include flame control and protection against overheating of the body. You should not save on this equipment: the extinguished flame of the burner or overheating can lead to disaster. It is also worth remembering that gas guns are sensitive to low temperatures, and at serious degrees can work unstable.

Gas heat guns include a hose and pressure reducer for connecting to a cylinder or mains.

DIESEL HEAT GUNS

Diesel appliances on the principle of operation are similar to the gas appliances, but they use diesel fuel some users even use kerosene and waste oil, which, of course, gun manufacturers do not approve .

Compared to other varieties of guns, the diesel heat guns can count a lot of disadvantages. Firstly, they have a fairly high weight: you have to transport the gun with the tank, and it, even empty, weighs something. Secondly, their design is more complicated.

Fuel is fed to the combustion chamber or a fuel pump or an air compressor. In the second case, the compressed air “draws” the fuel from the tank, on the same principle as the sprayer. Other types of guns do not need a forced fuel supply, hence the third disadvantage associated with the first two – the price of the “kit” with a tank and feeding system is higher than that of gas and electric models. Another “disadvantage” – additional units require additional maintenance, at least cleaning the fuel filter and air, if available . Diesel fuel is more polluted with extraneous impurities compared to gas, so you can include such guns only in non-residential premises with ventilation. However, even the gas guns are not designed for heating living rooms, although in emergency situations they use everything they can, including diesel.

But you can put up with these disadvantages of diesel guns, because they also have a lot of advantages. Fuel for diesel guns is available: diesel fuel is available at almost any gas station, the fuel consumption is very economical. Usually one filling is enough for the heater to work continuously for 10-15 hours. The transport of diesel fuel is safe, but gas cylinders are not. Besides, the use of diesel fuel is convenient from the point of view that the heating installation is not connected to the gas mains. The cost of heating in diesel models is low, and the power range is the same as that of gas guns, t. e. a suitable model can be selected for any size of rooms. In addition, the diesel gun can operate in a wide temperature range.

A separate class of diesel guns refers to indirect heating devices. In a conventional gun, all the combustion products get into the room, and in the guns indirect heating uses an additional circuit – heat exchanger. Hot gases pass through it and ejected outside the heated room through the chimney, and the heat is “removed” by the fan. Such guns have a lower efficiency than conventional, direct heated, the price is naturally higher, but you don’t need to worry about ventilation and airing.

Of course, the chimney – a pipe for the removal of gases, this gun is not included, it must be purchased and installed additionally, taking into account the specific conditions. Such models, designed for stationary operation, are used primarily for heating large volumes of rooms in the workplace. It is worth remembering that the work of diesel and gas heat guns still require a small amount of electricity usually between 50-200 W to power the fan and automation systems, so that a full autonomy with their help is not achieved. However, if you want autonomy when working in emergency mode, you can feed the gun from a small generator, batteries with an inverter or even on-board the car system also with the inverter – in this case the device that converts DC to AC 220 V.

DETAILS AND SAFETY SYSTEMS

Gas or diesel guns can be ignited with a piezor igniter or a spark plug. Electric guns usually have more than one heating element and allow you to adjust the power by connecting them together or individually. Almost always these models have another mode, in which the heating elements are not involved. There, the gun will work as a fan.

The possibility of regulating the flame power in the combustion chamber is quite difficult to implement, so the gas and diesel guns usually operate in the same mode. To reduce the temperature in the room, the gun should be turned off from time to time. Many models have a built-in thermostat. Its task is to maintain heat in a certain range, turning off heating when the set temperature is reached. The thermostat of most of the guns does not give any information, most often the words “min” and “max” are written on the scale, and the display of the current temperature value is not provided. Only some examples are equipped with a full-fledged temperature indicator.

Automatics of protection of almost all models includes automatic shutdown in case of overheating of heating unit or combustion chamber. When the fan stops the temperature of heating elements or combustion chamber rises very quickly, counting literally in seconds. To avoid serious damage and fire hazards, an overheating protection device turns off the heating elements or cuts off the fuel supply to the combustion chamber. Gas and diesel guns are usually provided with flame control: when the flame goes out the fuel supply is stopped. These are the basic protection stages, but there may be others, such as an oxygen sensor that switches the gun off when its concentration drops, a tilt sensor, flame stabilization systems, etc.

RULES FOR SAFE OPERATION

For effective and safe operation of the heat gun it is enough to follow some simple rules. Not to block the air intake and air duct in the first place. This rule must not be neglected under any circumstances, even if you are tempted to dry your clothes or shoes on the body of the heater. You also can not install the gun close to the wall and other obstacles: there will be poor air intake, and it is fraught with overheating.

Since the gun of any type has in its construction electrical devices, the working conditions must be appropriate: the normal level of moisture, protection from ingress of water. In addition, you must remember that some models operate from the network of 380 V and the wiring must match the capacity of the heater.

Although most heat guns are designed for use on construction sites and in industrial buildings, too much dust is contraindicated. Therefore, when working with power tools perforators or grinders it is advisable to turn off the gun and clean it until the dust is removed.

Airing is a must. No matter how high the efficiency is, there are still products of combustion in the air. So it is necessary to ventilate the room regularly to replenish the oxygen consumption.

Another requirement for efficient operation is an even distribution of heat fluxes in the room. For heating very large areas, it is necessary to use several guns at the same time. They can be subordinated to a single control equipment that will independently maintain the set temperature in the room, time to turn on and off the guns.

From the “consumables” for heat guns can be noted thermocouples, filters, transformers, etc. e. those parts that fail from time to time – no one is immune to it. Buying a replacement is not difficult. As for the installation, the experts say: those who know how, replace the part by themselves, others are better to turn to “a specially trained person”.

It is also worth recalling the human factor. Although they are equipped with metal casings and mostly look very solid, this is not a reason to handle them carelessly pull the cable, push . This is often observed at construction sites, where the principle “don’t own – don’t regret” is working.

The requirements for the use of a particular model, as a rule, are prescribed in the documents to the heating equipment. Be sure to familiarize yourself with them before connecting the gun. This will extend the life of the heater and save you money.