4       Interior shading devices

In cooperation with AEE

4.1       General principles of interior shading devices

Interior shading devices are mainly established in order to provide visual comfort by eliminating glare. Further, interior shading devices can contribute to the interior architectural design of rooms without influencing the exterior façade of the building. Because of the heat absorption happening inside the building (the transformation of short wave sunlight energy into long wave heat energy) interior shading devices are not as efficient as exterior shading solutions to reduce solar heat gains.

In rooms that are oriented north or east without risk for overheating in the summer, the following interior shading devices are in use (Figure 68):

§  Venetian blinds – horizontal blade construction, which can be lowered and elevated (1)

§  Roller blinds - textile curtains or foils, which are rolled up above the window  (2)

§  Pleats curtains – textile curtains, which are folded above the window  (3)

§  Vertical-blades - textile vertical blade curtains (4)

§  Curtains – textile curtains

 

	(1)	(2)
	(3)	(4)

Figure 68: Shading devices for interior shading

 

 

 

Usual window glazing lets more energy from the sunlight get inside than send back heat outside through the window. Short wave sun radiation is able to pass glazing, meets matter and then is transformed into long wave heat radiation, which cannot pass the glazing (high-pass filter). This physical mechanism leads to the well-known green house effect. 

The performance of interior shading systems can be improved through high-reflecting materials, like metal coatings or metalized textiles, which directly reflect sunlight outwards before light has been turned into heat.

In rooms that are orientated towards south or west, there is a risk for overheating in summer, the following interior shading solution can be used:

Foil roller blinds (Figure 69) - an effective solution for interior shading against sunlight and glare are foil roller blinds, which enable sight connection outwards even if they are closed. This specific foil material is vaporised with aluminium on its outside, still it is transparent and it reflects more than 80 % of the incident sun energy.

 

Figure 69: Foil roller blind with reflecting lamination [FOL08]

 

 

4.2       Practical implementation of interior shading devices

 

			Figure 70: Venetian blinds in a historic window	Figure 71: Fourfold divided interior window shutters

4.3       References

[FOL08]           www.folienrollos.de