Guidebook providing practical knowledge tips for heating applications
Heating know-how for commercial applications. Here you'll learn which type of mobile heaters is suited best for which type of professional requirement.
Whether you opt for a direct oil heater fan, a flue pipe oil heater fan, an electric heater or a gas heater – every mobile heating system has its individual benefits. To make sure that you find exactly the right heating solution for your specific application, we're providing you with some details of the properties here. Furthermore you'll learn under which circumstances you can also install a heater outside and how you calculate the heating capacity actually required, depending on the size of the room.
Mobile heating devices bring pleasant temperatures into the shell construction, the storage hall, the workshop, the greenhouse or the stable. Depending on the site of installation, however, completely different requirements are posed to the heating devices. Do you, for example, only want to heat a building during the construction phase or additionally also dry it quickly? Are you dealing with the heating of well-ventilated winter construction sites, or do you wish to bring agreeable temperatures into temporary accommodations, tents or workshops?
At Trotec you'll find the right heating device for every application
CONTENTS
2. Direct infrared radiant oil heaters (without a fan) Targeted infrared heat radiation
5. Electric hot-air fans: Comfortable, reliable, clean and quick warmth without oxygen consumption
7. Quick comparison: Which type of heating for which application?
8. How to also install heaters outdoors
Oil heater fan
Oil heater fans are divided into direct heaters without a flue pipe and indirect heaters with a flue pipe. In the following we'll describe the differences between the two systems to you and we'll point out the pros and cons to you.
Direct oil heaters
Heating capacity of 100 % ‑ for the use in well-ventilated interior spaces and roofed outdoor areas.
In a directly fired oil heater, the fan also see to the combustion air to then blow out the heated air. For this purpose, first, fuel is atomized, ignited and burned in the combustion chamber. Then the hot combustion gases are admixed to the main air current of the fan.
In addition to the heat, oil heaters also emit the combustion waste gases directly into the room. Therefore, direct oil heater fans have no chimney and are not suitable for the use in closed rooms without good ventilation (oxygen supply) – especially if these rooms are used by persons and animals. Since furthermore additionally approx. 1.6 kg water vapour per litre of fuel are released in the combustion process, direct heaters should never be used for construction drying – in this way the building would be submitted to permanent "forced humidification"!
On the other hand, direct oil heaters are suitable for the use in well-ventilated interior spaces or roofed over outdoor areas, since they provide the total heat generated. This process is therefore also referred to as 100 % heating capacity.
Good to know: Direct oil heaters ...
- are suited for the use in well-ventilated interior spaces and roofed outdoor areas
- generate a heating capacity of 100%
- emit the combustion waste gases directly into the room together with the heated air
- are unsuitable for closed rooms that are used by persons or animals
- cannot be used for construction drying, since the combustion generates approx. 1.6 kg of water vapour per litre of fuel
- must not be used in rooms with a fire hazard due to the storage of flammable substances
The functional principle of direct oil heater fans
Cold air is drawn into the interior of the oil heater by a fan. The air is guided through both the combustion chamber and around the outside and in this way is strongly heated. In addition to the hot air, this process therefore also blows the combustion waste gases out of the oil-fired heater.
Since the whole heat output is released 1:1 into the room, the efficiency of direct oil heaters is 100 % – which is ideal, for example, if you wish to heat well-ventilated halls, stables or roofed over outdoor areas quickly and effectively.
Direct infrared radiant oil heaters (without fan)
Targeted infrared heat radiation.
On construction sites, in storage areas or workshop halls, mobile infrared radiant oil heaters supply targeted warmth. In contrast to oil heater fans, infrared radiation does not warm the room air, but the objects at which it is directed. In particular in draughty areas in which the warm air of oil heater fans would simply be blown away, infrared radiation is an effective heating alternative – comparable to the natural principle of the warming solar radiation. Since infrared radiant oil heaters usually do not have a fan, no dust can be raised during heating operation either. Just as with direct oil or gas heater fans, the combustion waste gases of infrared radiant oil heaters are released into the room. The room to be heated must therefore be well-ventilated to ensure that the exhaust gases can escape and that a sufficient supply of oxygen is provided for.
The functional principle of direct infrared radiant oil heaters
The infrared radiant oil heater is provided with a large-surface ceramic plate which is strongly heated from the inner side by a flame in the combustion chamber. The hot plate then releases the heat to the outside in the form of infrared radiation. As the whole heat output is radiated 1:1 into the room, the efficiency of infrared radiant oil heaters is 100%, just like that of direct oil or gas heater fans.
Good to know: Direct infrared radiant oil heaters …
- heat objects with their infrared radiation, but not the air
- work without a fan and therefore, for example, do not raise any dust
- are suited for the use in well-ventilated interior spaces and roofed outdoor areas
- generate a heating capacity of 100%
- emit the combustion waste gases directly into the room along with the heated air
- are unsuitable for closed rooms used by persons or animals
- cannot be used for the purpose of construction drying, since the combustion generates approx. 1.6 kg of water vapour per litre of fuel
- must not be used in rooms with a fire hazard due to the storage of flammable substances
Flue pipe oil heaters (also referred to as indirect oil heaters)
No emissions scandal at Trotec! Fluel pipe heaters supply emission-free heat for indoor use.
Whether you require it for shell constructions, in storage facilities, in workshops or in the agricultural sector – the warm air of flue pipe oil heater fans does not contain any combustion waste gases. In the case of indirect heaters with a flue pipe the air to be heated is fully isolated from the combustion chamber. The air is heated while flowing past the enlarged area of the combustion chamber, the heat exchanger. The fan blowing warm air into the room to be heated also provides the required combustion air. But the combustion products are led away into the open air by a chimney ‑ the significant feature of "indirect" heaters.
In order to obtain both clean and dry warmth, we therefore recommend using an indirect oil heater. Because in contrast to the direct oil heaters, neither exhaust gases nor water vapour enters the room air. Instead, both of them are dissipated into the open air by the chimney.
Indirect oil heaters are ideally suited for rooms in which ventilation is only possible to a certain extent, but which still are to be used by people and animals. They are also a good choice for speeding up construction drying as well as in rooms where there is a fire hazard due to combustible substances.
Good to know: Indirect oil heaters …
- fully isolate the heated air from the combustion chamber
- feature a flue pipe as their significant characteristic
- Unlike directly-fired oil and gas heaters, dissipate the combustion gases via the chimney and do not release them into the room
- attain a thermal efficiency of approx. 92 to 95 %, since approx. 5 to 8 % of the heat output is lost through the chimney
- produce clean (soot-free) and dry (condensate-free) warmth
- can be applied in rooms without ventilation, which are used by persons or animals
- are suited for speeding up construction drying
The functional principle of indirect flue pipe oil fan heaters
These devices also draw the cold outdoor air into the heating unit by means of a fan. In contrast to direct oil heater fans, the combustion chamber (or the heat exchanger) is not fully isolated from the air current that is blown out, preventing the exhaust gases and the water vapour generated in the course of combustion from being mixed with the hot air blown out into the room.
Instead, the two undesired by-products are dissipated to the outdoor area via a chimney. This is the reason why the clean and dry air of flue pipe oil heaters is especially suitable for areas used by persons or animals as well as for assisting construction drying.
The efficiency factor of indirect oil heaters with a flue pipe, however, is a bit lower than that of direct oil heaters without a flue pipe. Since approx. 5 to 8% of the heating energy of indirect flue pipe oil heaters is dissipated into the open air through the chimney, along with the exhaust gases and the water vapour, the efficiency in contrast to direct oil heaters without a chimney flue pipe is only approx. 92 to 95% instead of 100%.
Gas heater fans
Gas heater fans are also direct heating systems without a flue pipe. They dissipate their exhaust gases into the room along with the heat generated.
Gas heaters
Cost-effective instant heat for the use in well-ventilated interior spaces and roofed outdoor areas
Gas is a low-priced energy source that is easy to transport. The gas heater fans from Trotec offer an unmatched value-for-money ratio where the effective immediate heating of well-ventilated construction sites, workshops, storage facilities, garages, stables, greenhouses or also roofed outdoor areas, tents and camping applications are concerned. Safety is also a major issue: An integrated temperature sensor serves as flame failure protection and prevents the emission of unburnt gas. In the case of overheating the gas supply is automatically interrupted by means of a safety thermostat, while the fan for cooling continues running. The specially shaped discharge grille of the Trotec gas heaters prevents direct contact with the flame whilst ensuring an optimally swirled, high-volume current of warm air. With propane gas, gas heater fans can also be used at very low temperatures. The boiling point of propane gas is -42 °C. Owing to their extremely compact design, the heating devices can be transported comfortably even in the smallest of car boots.
Since connection hose and pressure reducer for connecting the gas cylinder are already included in the scope of delivery, nothing more than a socket and a propane cylinder is required for the heating operation. Once in operation, agreeable warmth begins to spread immediately, seeing as the integrated blower ensures an effective air flow made up of sucked in ambient air and blown out warm air. In this way even larger rooms of up to approx. 300 m³can be quickly heated. However, since the combustion waste gases are also released into the room just like it is the case with direct oil heaters, optimum ventilation of the area to be heated must be absolutely ensured – especially if it is used by persons and animals. In contrast to oil heater fans, though, heating with gas does not produce any Diesel or oil fuel odours. However, the combustion process also generates approx. 1.6 kg of water vapour per litre of fuel in this application.
Good to know: Gas heater fans …
- are suited for the use in well-ventilated interior spaces and roofed outdoor areas
- generate a heating capacity of 100%
- emit combustion waste gases directly into the room along with the heated air
- are not suitable for the use in closed rooms
- cannot be used for construction drying, since the combustion generates approx. 1.6 kg of water vapour per litre of fuel
- must not be used in rooms with a fire hazard due to the storage of flammable substances
The functional principle of direct gas heater fans
The gas-fired direct heaters of the TGH-E series draw in the ambient air through a blower, then heat the main air current using a gas burner and finally discharge the heated air to the room. This means that also the exhaust gases produced by the combustion process as well as water vapour is blown out into the room along with the heated air.
The room or the roofed outer area to be heated must be very well-ventilated by all means, so that the exhaust gases are blown away by a natural draught and oxygen can enter the room permanently. Due to their high development of humidity during operation, gas heaters cannot be used for assisting construction drying.
Electric heaters
Electric heaters are divided into electric hot-air fans and infrared radiant heaters. Both variants have their individual advantages.
Electric hot-air fan
Comfortable, reliable, clean and quick warmth without oxygen consumption.
On construction sites, in storage facilities, in market stalls – no one likes to stand, let alone having to work, in the cold longer than necessary. And thanks to the modern and innovative electric heating solutions like those offered by Trotec, no one has to.
The reason why electric heaters are so popular is their almost infinite operational capability. Electric heaters deservedly claim to be the most reliable, quickest, and the most convenient method for problem-free heating.
Therefore electric heater fans can be practically used everywhere, since in contrast to directly fired gas or oil heaters they neither consume oxygen nor generate combustion waste gases. This means that no supply or exhaust air openings are required – the corresponding power connections is all that you need.
As a result, they can be used throughout all sectors – for instance for construction projects, in party tents, storage facilities and workshops, on ships, in switching stations, stables, garages and in temporary accommodations. In particular, electric heaters serve to assist dehumidifiers with construction drying, since higher room temperatures significantly shortens the drying periods.
Whether you use conventional heating wires, heating coils or ceramic PTC heating elements – at Trotec you'll find the right electric heater solution for your application.
Good to know: Electric hot-air fans …
- are considered as the most reliable, the quickest, and the most convenient heating method
- generate a heating capacity of 100%
- do not consume oxygen
- do not generate any combustion waste gases
- produce clean (soot-free) and dry (condensate-free) warmth
- can be practically used everywhere without any problems, also in unventilated rooms used by persons or animals
- are suited for speeding up the process of construction drying
- depending on the electricity tariff, usually produce higher operating expenses per kW than oil- or gas-powered heating devices
What is the difference between electric heaters with ceramic PTC heating elements and electric heaters with a heating coil?
In the two following diagrams, the PTC ceramic heater element is marked with (A) and the heating spiral technology is marked with (B) .
Compared to the conventional heating coil technology (B) the shorter heat-up times are not the only distinguishing feature of Trotec fan heaters with PTC ceramic heating elements (A). There are also process-related differences in the response behaviour of the heating elements.
Although both devices maintain the preselected target temperature (orange line) by means of thermostat control using a two-position controller, the respective temperature adaptation takes place significantly more slowly and with greater deviations from the desired target temperature in case of devices with heating coils. The reason for this is the different conductivity behaviour of the heating elements: if current flows through the heating coils, the coils will always have the same temperature once they have heated up. For controlling the desired room temperature, the power supply is first interrupted, making the coil cool down, and then re-activated by the thermostat so that the coil heats up again completely before it is switched off again when the set target temperature is reached.
This "on/off process" causes significantly greater temperature fluctuations around the desired target temperature than with ceramic heating elements, for the material of the latter provides an integrated temperature self-regulation.
The hotter PTCs get, the higher is their electrical resistivity, resulting in less current flowing through the heating element and in a reduced heating capacity, and thus in significantly lower temperature fluctuations and less switch-on and switch-off processes in thermostat-controlled operation.
For this reason, ceramic fan heaters are able to create more even room temperatures for temperature-sensitive manufacturing processes as well as a more agreeable room climate.
However, PTC fan heaters (A) are not suitable for dusty environments (e.g. coarse dust, construction dust, sawdust, etc.), because there is the danger that the fine mesh PTC heater battery is clogged by dust. As a result the air current is blocked and the ceramic PTC heating device fails. Therefore the PTC heating element must be checked for pollution at regular intervals and cleaned with compressed air, if necessary. Electric heating devices with heating coil technology (B) are therefore more suitable for dusty environments, since they are not blocked by dust as quickly.
- Quick heat-up performance
- Only minor variations when maintaining the preset target temperature (approx. +/- 2°C)
- Lower blow-out intensity and throwing range of the warm air in comparison to electric spiral heaters. In large rooms this may possibly produce uneven temperature zones
- Not suitable for dusty environments (e.g. construction sites, stables), since the fine mesh PTC heating element may clog (regular cleaning if required)
- Suitable for allergy sufferers, since due to the lower temperatures on the heating element no dust, hair or lint is burnt and therefore neither odours nor residues are released into the air
- Slower heat-up performance
- Greater variations when maintaining the preset target temperature (approx. +/- 4°C)
- Higher blowing-out performance and throwing range of the warm air. This also allows larger rooms to be heated more steadily
- Also suitable for dusty environments (e.g. construction sites, stables), since the heating elements do not clog (no regular cleaning effort required)
- Not suitable for allergy sufferers, since dust, hair or lint may burn at the heating element due to the high temperatures and therefore odours and residues may be released into the air
Infrared radiant heaters
Pleasant, targeted warmth and no warm-up time required – ideal for heating workplaces.
Whether you require them for heating applications in site trailers, workshops, storage facilities or stables – modern infrared radiant heaters produce direct heat immediately after switch-on, based on the natural principle of solar radiation. Unlike with the use of conventional electric heating devices the infrared rays here do not heat the room air but materials and objects they are directed at – such as walls, the floor or the ceiling. These can store the heat for a longer period than air and then release it to the room in the form of secondary radiation. Infrared radiation immediately generates an agreeable sensation of warmth on the skin.
The intense infrared heat is produced with an efficiency of 100% – a clean way of heating without causing noise, smells or dust circulation, hence also suitable for allergy sufferers. Whether you use it as wall radiator or in a free-standing version – since infrared radiant heaters work without causing noises and do not consume oxygen they can be used without any problems in environments with persons and animals. Depending on their IP protection class, they are sealed against rain and dust and therefore also for unroofed outdoor areas.
Specially for construction drying:
Infrared heating panels – steady heat distribution over the whole surface
Professional infrared heating panels are suitable for the surface drying of walls in new buildings or after water damage, as they produce dry (condensate-free) and large-surface heat radiation. Especially massive brickwork can be dried faster as compared to conventional dehumidification. Up to three professional infrared heating panels of the Trotec models TIH 350+ and TIH 650+ can be combined quickly and stably in for large-scale drying in batch mode.
Good to know: Infrared heaters …
- are ideally suited for the targeted heating of workplaces
- provide direct warmth (100 % heating capacity) without any warm-up time
- do not consume oxygen
- do not generate any combustion waste gases
- produce clean (soot-free) and dry (condensate-free) warmth
- can be used in interior and outdoor areas, depending on their IP protection class
- can be applied in rooms without ventilation, which are used by persons or animals
- in the form of professional infrared heating panels are suitable for speeding up construction drying
Trotec offers you infrared radiant heaters from 1.2 kW to 20 kW. Click here to go to the overview of infrared radiant heaters and to the infrared heating panels for professionals from Trotec.
Quick comparison: Which type of heating for which application?
Direct oil heaters without a flue pipe and infrared radiant oil heaters
(from 20 kW to 100 kW)
Direct oil heaters and infrared radiant oil heaters are ideally suited for the use in well-ventilated interior spaces, where the whole heat that is generated is actually provided (100% performance).
Note:
In addition to heat, direct radiant oil heaters (without a flue pipe) and infrared radiant oil heaters also emit combustion gases directly into the room.
For this reason, they are unsuitable for poorly ventilated, closed rooms (oxygen supply) if these rooms are used by persons or animals.
Furthermore they additionally generate approx. 1.6 kg water vapour per litre of fuel during the combustion process and therefore they are not suitable for drying the building structure. When using direct radiant oil heaters to speed up a process of construction drying, there would at worst be more moisture in the building than before!
In rooms with a high risk of fire hazards, where flammable substances are stored, direct oil heaters and infrared oil heaters must not be used.
Direct gas heaters
(from 10 kW to 30 kW)
Gas heaters are suitable for the use in well-ventilated interior spaces and roofed outdoor areas, actually providing the whole heat that is generated (100 % performance).
Note:
In addition to heat, gas heater fans also emit combustion gases directly into the room.
For this reason, they are unsuitable for poorly ventilated, closed rooms if these rooms are used by persons or animals.
Furthermore, the combustion process generates approx. 1.6 kg of water vapour per litre of fuel. Direct gas heaters are therefore not suitable for construction drying. When using gas heater fans for construction drying, in the worst case there would be more moisture in the building than before!
Also in rooms with a high risk of fire hazards, e.g. due to the storage of flammable substances, gas heaters must not be used.
Indirect radiant oil heaters with a flue pipe
(from 20 kW to 225 kW)
The generation of clean and dry warmth without combustion products or water vapour ending up in the room air requires the use of indirect heaters (with a flue pipe).
In the case of indirect radiated oil heaters the air to be heated is completely separated from the combustion chamber and can be guided either directly into the corresponding rooms or via tubes.
The combustion waste gases, however, are discharged into the open air through the flue pipe. Therefore the efficiency of the heating capacity is not 100% as is the case with direct radiant oil heaters, but only approx. 92 to 95%, since part of the hot air is lost through the chimney together with the exhaust gases.
Indirect heaters are therefore ideally suited for rooms used by persons or animals and in which ventilation is only possible to a limited extent.
Electric heaters and infrared radiant heaters
(from 0,3 kW to 80 kW)
Electric hot-air fans and infrared radiant heaters are suitable as a reliable, quick and convenient heating solution. All it takes is a corresponding power connection and there is no additional handling expenditure as is the case with oil or gas heaters. Just like direct oil or gas heater fans, they offer an efficiency of 100% heating capacity. The heating process, however, produces neither combustion waste gases nor water vapour and no oxygen is consumed. The use in rooms that are used by persons and animals is therefore no problem.
Electric heaters are often used for construction projects, in marquees, storage facilities and workshops, on ships, in switching stations, stables, garages and in temporary accommodation. Electric hot-air fans are furthermore suitable to assist dehumidifiers in the process of construction drying, as they do not release any condensate (water vapour). In the case of the infrared heaters, IR heating panels are recommended for construction drying.
Depending on the electricity tariff, the operating expenses of electric heaters per kW are usually higher than those of oil- or gas-powered heating devices.
How to also install heaters outdoors
Indoors or outdoors? Actually, there shouldn't be two opinions about where a mobile heater finds its optimum location. Neither from the aspect of efficiency nor from an ecological point of view there's a reason why the heater should not be installed in the house. Unless it would simply be too big – but even for this case we'll find a solution. However, if it absolutely does not fit: of course we have the suitable equipment at the ready for you if you choose to make a change "from outside to inside".
Heaters with a performance of more than 100 kW are often placed in front of the building to be heated because of their size. The heater now warms the cold outdoor air and blow it into the building via air transport hoses.
Naturally it is clear that a heater which is installed outside requires a considerable greater amount of time, energy and fuel to provide the desired temperature in a room than a heater installed inside. This is because this heater heats on the principle of recirculation, which means that it just continues heating the room air that has already been heated.
Since the fuel consumption in the case of an outside installation of the heater is often two to three times higher, with regard to the common models Trotec always offers heaters with a compact design, if possible. As these devices, with their width of only 80 cm, fit through all normal doors!
If you are looking for a solution which only fits "outdoors"
Then you should also be sure to rely on the proven Trotec brand quality when it comes to the air transport hoses. The combination hose SP-C for the connection to mobile oil and electric heating units, for instance, on its first two metres consists of especially resilient neoprene tissue, designed for a temperature range from -24 °C to +150 °C. With its standard length of 7.6 m, which can be optionally extended, you can decide flexibly where you wish to install your mobile heater.
How to calculate the heating capacity required:
Online calculators
With our Heating capacity calculator You can easily and conveniently calculate yourself online which heating capacity you require for your rooms.
If you prefer carrying out the calculation using a pen and paper, please find below a list of all relevant aspects for calculating the heating capacity.
Or call us under +49 2452 962-160 and we'll be happy to help you!
The following information is required for calculating the heating capacity:
1 Which room temperature is to be reached?
2 What is the current or expected minimum outside temperature?
3 What is the total volume of the room to be heated?
4 Which average heat transfer coefficient (U-value) does the building have?
The temperature to be reached depends on the individual requirements.
Calculation of the heating capacity for rooms of UP TO 1,000 m³
The following formula can be used to quickly calculate the heating capacity for small rooms sized up to 1,000 m³:
Room volume (Q) x U value x temperature difference = heating capacity in kcal
Conversion factors:
1 kcal = 1.16 watts = 4 BTU / hour
Calculation of the heating capacity for rooms FROM 1,000 m³
The diagram below can be used to quickly calculate the heating capacity for large rooms sized 1,000 m³ and more.
The values stated are guided by the capacity demand for temporary heating with normal insulation and a minimum outside temperature of -5 °C.
Example calculation:
In order to heat a room volume of 5,000 m³ at an average outdoor temperature of -5 °C by 17 °C to a desired room temperature of 12 °C you'll require approx. 23 watts / m³.
The total heat requirement in this example calculation is therefore 5,000 x 23 W = 115,000 W = 115 kW
Calculation information:
With a good thermal insulation 15 % of the capacity can be deducted, should it be poor, 15 % have to be added.
Legal notes / disclaimer:
These notes have been compiled the best of our knowledge and belief, however, they do not replace a professional expert consultation. For calculating your actually required heat capacity, please refer to our expert consultants. All results of the calculation serve to the purpose of rough estimation only. Trotec GmbH will in no case assume any liability for any consequential damages. The use shall be at the user's own risk and responsibility. Our General Terms and Conditions apply in addition.
We're happy to be of service! Your contact to Trotec.
We'll be pleased to be at your service for a non-binding consultation. Our committed service team will analyze your individual requirements and offer you a tailor-made heating solution. On the basis of our long-standing experience we can always compile the optimum device combination for you – offering you the best performance at the best price. We're looking forward to hearing from you!
Purchase: +49 2452 962-400 • Rental: +49 2452 962-160 • E‑mail: info@trotec.de
(We're at your service on Monday to Thursdays from 8 am to 5.30 pm and on Fridays from 8 am to 5 pm.)
Please also always use our contact form. We'll get in touch with you immediately!
E-mail: info@trotec.de
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