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light considerably and cause glare. Unlike the roller shutter, there is no option for pivoting a vertical roller blind outwards and upwards. The maximum/minimum dimensions are approx. 40/300 cm for the width and 40/400 cm for the height. The maximum permissible area is approx. 8 m2, the ideal width-to-height ratio 1:3.

Semi-awnings: This is an elaborate variation on the vertical roller blind which, thanks to an additional roller plus stays, can be pivoted outwards and upwards to permit a partial view of the surroundings. Apart from a minimum height of 120 cm, the maximum/minimum dimensions and maximum area are the same as for vertical roller blinds.

Fig. 83: Semi-awnings to the windows, straight-arm awnings and vertical blinds to the balconies

Max Ernst Haefeli: Rotach development, Zurich (CH), 1928

Fig. 83: Semi-awnings to the windows, straight-arm awnings and vertical blinds to the balconies

Max Ernst Haefeli: Rotach development, Zurich (CH), 1928

Fig. 81: Straight-arm awning mounted below the lintel access from outside

Fig. 78: Louvre blind integrated into the wall access from outside

Fig. 79: Roller shutter with angled positioning option integrated into the wall access from inside

Fig. 80: Semi-awning surface-mounted access from outside

Fig. 81: Straight-arm awning mounted below the lintel access from outside

Fig. 82: Articulated-arm awning surface-mounted on soffit of balcony slat

Fig. 84: Large articulated-arm awning forming a movable canopy

Oliver Schwarz: factory building, Ebikon (CH), 1996

Fig. 84: Large articulated-arm awning forming a movable canopy

Oliver Schwarz: factory building, Ebikon (CH), 1996

Fig. 85: Folding shutters providing sunshading for balconies

Baumschlager & Eberle: Hotting Estate, Innsbruck (A), 1999

Fig. 85: Folding shutters providing sunshading for balconies

Baumschlager & Eberle: Hotting Estate, Innsbruck (A), 1999

Straight-arm awnings: Two straight stays, their outer ends connected to a tube, unroll a fabric blind by means of gravity and position this at a certain angle to the facade. This type of shading was often popular for balconies in the past. The fact that the window is not completely covered guarantees a link with the outside world. The maximum/ minimum dimensions and the maximum area correspond to those of vertical roller blinds; the length of the straight stays is 80-150 cm.

Articulated-arm awnings: Two or more articulated arms enable a fabric blind, which is rolled up when not in use, to be extended to any desired position between minimum and maximum. An additional hinge enables the angle to be adjusted as well. This is the most popular type of sunshading for balconies and patios and is also employed for shading large (display) windows. Widths of between 2 and 7 m are possible, the maximum arm length is 4 m.

Hinged, folding and sliding shutters: These, the archetypal movable sunshades, are usually made from wood or aluminium. When not in use, the leaves are folded together adjacent to the reveal or stored in front of a plain part of the f acade. The dimensions depend on the particular window.

Insulating glazing with integral louvres: In this arrangement a louvre blind is integrated - gastight - between the two panes of an insulating glazing unit. As explained above, this system does not provide optimum protection against heat radiation because the temperature rises in the cavity between the panes and some of the excess heat is emitted inwards in the form of long-wave infrared radiation. However, the system is suitable for high-rise buildings because fitting the blind between the panes of glass protects it against wind forces and soiling. A defect in the blind results in the entire glazing unit having to be replaced.

Surface-mounted or flush?

With the exception of the last two examples all the other types of sunshading can be installed as surface-mounted elements visible on the facade or integrated into the window/door head detail. The latter variation results in the sunshading element being essentially concealed when not in use. One hybrid solution is the installation below the window/door head behind a fascia panel flush with the facade. Articulated- and straight-arm awnings are frequently fitted beneath the balcony of the floor above.

If the sunshading element is integrated into the window/door head detail, easy access for maintenance and replacement must be guaranteed. Furthermore, the continuity of the layer of thermal insulation must be taken into account.

Antiglare measures: the brief

Glare is caused by direct sunlight and its reflection by internal surfaces, but also by daylight reflected by external objects (e.g. light-coloured buildings, snow-covered surfaces, etc.). In contrast to the sunshading issue, in which the heat radiation comes from a precisely defined direction, the incidence of the light and the resulting glare depends on diverse factors related to the particular conditions.

Glare is also an individual, subjective reaction influenced by the activities of the person concerned. For example, persons working at computer screens are more sensitive to glare than those writing manually at a desk.

Fig. 86: Surface-mounted roller shutter boxes as a design element on the facade

Ernst Gisel: housing and studios, Zurich (CH), 1953

Fig. 86: Surface-mounted roller shutter boxes as a design element on the facade

Ernst Gisel: housing and studios, Zurich (CH), 1953

Changing demands placed on the internal functions calls for a fine regulation or redirection of the incoming daylight, even complete blackout measures (e.g. classrooms).

As with sunshading, antiglare measures also involve limiting the view of - and relationship with - the outside world. This affects both the architecture (unwanted intro-vertedness) but also the human psyche (feeling of being excluded).

For these reasons antiglare measures should be (re)movable wherever possible. Although some of the sunshading forms described above can also prevent glare (e.g. louvres), antiglare measures are advantageous when fitted internally - for glare still occurs during the heating period when solar energy gains are undoubtedly desirable.

Types of antiglare measures

There are two main ways of preventing glare, which, however, can be subdivided into a number of variations.

Curtains: This traditional form of preventing glare and creating privacy is made from a fabric, which can be chosen to determine the light permeability. The level of incoming light can be controlled by using two or more layers of curtains with different light permeability (e.g. net curtains during the day, opaque curtains at night). However, as curtains can be moved only horizontally and not vertically, which would be necessary to track the sun properly, they must be drawn completely in order to prevent glare. Modern variations made from efficient high-tech textiles are available which achieve good reflection but with little loss of transparency. Vertical louvres, which can be rotated about their longitudinal axis, are the only form of "curtains" that permit the incoming light to be adjusted to suit the position of the sun.

Blinds: Vertical blinds with a corresponding opaque coating are often used to darken classrooms or other teaching facilities. Louvre blinds enable precise regulation of the incoming light, right up to complete exclusion. A relationship with the outside world is maintained by adjusting the angle of the louvres. The colour and material of the louvres have an influence on the quality of the light as perceived subjectively in the room, e.g. wooden louvres close less tightly but establish a warm light. Aluminium light-redirecting louvres guide incoming light through appropriately positioned louvre profiles into the depths of the interior and achieve consistent illumination plus a gain in passive solar energy through storage of the heat in solid parts of the building - and without any glare component.

Fig. 87: Curtains for preventing glare and for partial exclusion of the surroundings

Ludwig Mies van der Rohe: New National Gallery, Berlin (D), 1968

Fig. 87: Curtains for preventing glare and for partial exclusion of the surroundings

Ludwig Mies van der Rohe: New National Gallery, Berlin (D), 1968

Fig. 88: Internal louvre blinds achieve diffuse interior lighting effects, the surroundings become blurred outlines

Alvar Aalto: Villa Mairea, Noormarkku (FIN), 1939

Fig. 88: Internal louvre blinds achieve diffuse interior lighting effects, the surroundings become blurred outlines

Alvar Aalto: Villa Mairea, Noormarkku (FIN), 1939

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Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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