Only the sun does it better...
Only the sun does it better...
1. Purpose of use Electric heating panels are suitable to use where high user's comfort is demanded. It can also be used for very economic heating in environment where standard conventional heaters are less suitable. Radiation heatings of recommended types are suitable for assembly heights from 2,5 m up to 8 m. They can be very well combined with other heatings such as heating floors or convectors. They can also serve as a supplementary heating.
According to the heating mode we distinguish use of radiant panels :
in predominantly systematic mode of heating which can be used in objects where we expect relatively high level of comfort and which are well enough heating insulated
in interrupting heating mode when during meantime the walls, ceiling and floor temperature decreases to relatively low values.
These are less insulated objects with often high thermal capacity of walls. These are used only occasionally and it would be non-economic to heat the space in a standard way including heat storage into perimeter constructions. In these cases the radiant heating brings almost immediate feeling of warm through direct radiation on clothes and exposed body parts after coming to operation. Feeling of less comfort as a consequence of cold building constructions is compensated with extraordinary economy of operation. This is very important for high ceiling objects.
Typical objects in interrupting heating mode are
heatings in churches, chapels, concert and lecture halls
2. Typical design Radiant panels are manufactured in two basic designs:
1) High-temperature panels - are equipped with flat radiation surface which guarantees radiation from up to 180°C angle ( so called hemispheric radiation ). Temperature at the surface of radiating segment is approx. 350°C. This high temperature enables relatively high density of radiant flow. That is why these panels are designed for suspending in high places 5-8 m.
Radiant with flat radiation area
2) Low-temperature panels - have also flat radiating area. Contrary to high-level panels is the surface of radiating area max. 110°C. Density of radiant flow is lower. Recommended height of panels placement is 2,5-3 m.
|Energy radiated by the
surface of an object is
proportional to fourth
power of absolute temperature.
E..... radiating capacity of an object (W/ m2)
e .....proportionate radiating capacity - emissive potential
Co... emissivity coefficient of a perfectly black object ( 5,67 W/m2 . K4)
T.... absolute temperature (°C)
Total radiant flow - object radiant output with surface area S (m2 )
area › higher radiated
High-temperatures panels - constructions
Aluminium segments with pressed-in heating rods are heating elements. Segments are equipped with special cover SILICATING which increases heat energy radiation into heated space. In accordance with output are panels equipped with 1,2 or 3 segments. Heat insulation is from mineral cotton wool. Panels are covered with sheet-metal varnished body.
Basic technical data:
Low-temperature panels - construction
closed body from FeZn metal plate equipped with special inner surface Thermoquartz and outer surface Thermocrystal which increase emissivity of the panel. Heating element - heating foil or heating cable. Inner insulation is from mineral cotton-wool.
Basic technical data:
Low-temperature panels with special design
panels for church pews heating - installation of church pews in vertical position in front of sitting people. Lower surface temperature approx. 80°C, IP20 - output line 100,200,270,330,400 W. Panels with increased covering - IP 54, IP 65 - for explosive environment EExell T3, panels output 700W, marking ECOSUN IKP, IN, IN - 2
When designing output, number and location of radiant panels it is suitable to proceed as follows:
1) calculate heating loss of a specific area Q [W]
2) select heating mode in accordance with the character of a future object operation
Systematic heating mode with good level of heating comfort:
heat passage coefficient to (U): walls < 0.5 W/m2K, floors at terrain < 0.5 W/m2K, ceilings < 0.35 W/m2K. Higher values to (U) increase operating costs and decrease heating comfort. Total input of all heaters set up to 20% higher than calculated heating loss because of higher heating system dynamics:
P= 1,2 * Q [W]
to check the input size for area unit, whereas applies P/S<150W/m2
S ......... floor surface of an area [W]
set minimal number of heating units n for creation of homogenous radiant field n> S/H2
H .......... expected installation height [m]
The more heating units enable heating comfort but increases acquisition costs
calculate average input of one heating unit and from output line of appropriate type select closest face-value
Specify number of heaters according to total input
Pn = P/a » Pjm
n = P/Pjm
- propose scheme of even location of individual panels. It is necessary to respect frame distances and even distances of panels according to scheme figure
- determine installed height according to frame recommendation in table or through the use of nomogram
will be < 8K, guarantees heating comfort.
After realisation we recommend to verify real size with temperature measurement.
Systematic heating mode with lower level of heating comfort
Zone heating is a mean of heating when only exposed, relatively small areas ( case of little heated halls ) are heated with radiant heat in large areas which are not globally heated
Interrupted heating mode in objects heated for short-term stay of people.
These are mainly churches, concert halls in historical objects etc. with high ceilings, social halls
These large area objects are very expensive to heat in interrupted mode with conventional heating devices such as storage heaters, convectors and various types of "radiants". These high operation costs are caused by the fact that it is necessary to heat very huge air content from low temperatures up to demanded temperature (comfort). And this all in relatively short time period. Because radiation heats the air only secondarily from radiated objects, comfort environment can be reached in such areas much faster. Therefore radiant heating is for interrupted mode of heating much more effective.
It is not sufficient for heat comfort only to heat the air on certain temperature. Feelings of heat or cold perception are more complex and are influenced by:
Determining importance have temperatures of areas limiting heated area e.g. walls, ceiling, floor, windows. Cool walls remove radiated heat from exposed skin and clothes. Cold walls or to the contrary high temperature of radiant source is perceived this way.
warm air up to 30°C
Walls, ceiling, floor up to 10°C
NON-COMFORT- too cold
walls, ceiling, floor up to 25°C
Air up to 5°C
NON-COMFORT - cold
Walls, ceiling, floor up to 26°C
Fresh air up to 15°C
air 20°C, Walls, ceiling, floor 20°C
In case of radiant heating, substances are heated inside of room including bounding surfaces and simultaneously proceeds cooling. This cooling is through heat conduction, radiation and also convection. For walls with large surfaces is the cooling process dependant on heat insulation degree. One of the criteria for assessment of environmental heat comfort is so-called asymmetry of radiant heat, especially in vertical direction.
Height of the temperature measured at half-sphere of ball-shaped thermometer depends on the source temperature and at distance between source and measurement point. For reaching satisfactory heat feeling of a person exposed to a radiation the asymmetry respected must be max. 8 K.
Comfort environment may be characterised by relation between air and walls temperatures. Half of their sum should be around 18°C while air flow not more than 0,25 m/s and relative humidity 40-60%.
Surface temperatures of low-temperature panel
ECOSUN panel surface temperatures