Infrared radiant heating is a radiative heating system widely used in industrial settings. When buildings are poorly insulated and it is not necessary to heat an entire volume, this heating technique is highly appreciated.
Indeed, the radiation favors surface heating, resulting in an optimal and immediate feeling of comfort; like moving from shade to sun in summer.
The different technologies
The two technologies mainly used are:
– dark tube heaters
– luminous radiant panels
Dark tube heaters
An air/gas burner generates a flame heating a steel tube. The surface of the tube reaches a temperature ranging from 300°C to 600°C and emits infrared radiation. This is oriented towards the desired area thanks to the reflector. The latter includes insulation in the most recent models.
This technology often requires evacuation of the burnt gases to the outside, particularly in public buildings.
Luminous radiant panel
An air/gas mixture is injected through a perforated ceramic plate in which combustion takes place. Unlike the dark tube heater, the temperatures reached by the ceramic plate are around 900°C. The ceramic burner is also surrounded by a reflector to direct the maximum radiation towards the ground.
The burnt gas, on the other hand, is released within the enclosure of the heated area, which is why this appliance will be used in well-ventilated areas. The seasonal energy efficiency of this technology can exceed 100%.
Advantages and disadvantages
The main advantages of these two technologies are:
- A feeling of warmth felt very quickly after start-up
- Low maintenance and good robustness
- A relatively simple implementation
- The possibility of orienting the devices to adjust the heated surface as needed
- Seasonal energy efficiency >100%
The disadvantages are mainly related to the implementation of these devices:
- A minimum height of 5m is recommended
- In case of restructuring of the area, it is necessary to reposition the radiant heaters
- Risk of overheating of heat-sensitive objects if too close to radiant heaters
- Shading problem and fire hazard near an overhead crane
When should these devices be changed?
The yields of these devices are excellent at installation, but many factors significantly reduce them.
In addition, older generations of these devices are not necessarily up to current safety standards .
Dark radiation tube
- Intense use of the tubes reduces the thickness of the latter over time which results in dark red tubes for the first few meters and can cause the tube to puncture and gas to leak into the volume
- The tube may deform over time and an arrow will appear
- Beyond 15 years, dark radiation tubes lose their performance
- The old devices are not equipped with double gas valves against leaks at the injector and with differential pressure switches to control the tightness of the tubes
- A dark radiation tube not insulated at the top loses 40% of its efficiency
Luminous radiant panel
- The ceramic plates can clog and the holes become clogged, which reduces the heating capacity of the radiant
- The ceramic plates crack over time which requires a replacement of the plates at a minimum
- Beyond 15 years, radiant heaters lose their performance
- An uninsulated radiant heater at the top loses 40% of its efficiency
In the end, dark tube or radiant light?
The qualities of these two technologies are equal even if the performance of the radiant light is higher.
The choice between these two technologies is above all linked to the quality of insulation of the building envelope and its airtightness .
A radiant heater will be favored in buildings that are very poorly insulated and have a high rate of air renewal since the ceramic plate reaches 900°C and therefore provides a very significant feeling of heat.
Conversely, a dark tube reaches 400°C and is therefore used in buildings with low to medium insulation and with a standard air renewal rate .