India owns a rich, glorified and diversified heritage. Visit of historical sites, such as Red Fort (at Agra, New Delhi), Taj Mahal (Agra), Fatehpur Sikri (Agra), Golkunda Forts (Hyderabad), etc. gives information about the prestigious, glorified and flourished pasts. These historical monuments are rich sources of historical information about our culture, traditions and past. These monuments are perfect examples of extreme engineering built-up during the period when heavy constructional equipment were not available.
Most of the historical monuments have been either declared as World Heritage Site by UNSECO or under maintenance by national or international agencies. In India, Archaeological Survey of India (ASI) is successfully accomplishing the maintenance and protection of historical monuments and related sites.
Recently, during a visit of Govindgarh Fort at Amritsar, Punjab, the illumination of fort was of worth appreciation. While attending the light show, it proves that the efficient and adequate façade illumination designs of these historical monuments can give rebirth to their glorified pasts.
Thus, lighting design of façade plays an important role in revealing facts of the buildings, monuments etc. In fact, monument with suitable façade lighting can create a lively effect of historical past. Hence, importance of suitable, efficient and adequate façade lighting illumination cannot be ignored.
Regarding the façade illumination design, two concepts (viz. wall washing & wall grazing) required to be carefully considered during design stage. A brief discussion is provided here for ready reference of the designers:
Wall washing as the words are self-explanatory, can be explained as washing of wall surface uniformly by using light i.e. uniform illumination on wall surface. This can be achieved by uniform distribution of lumen on all over the surface of the wall from top to bottom, without creating any patches of overcast lumens. With the selection of suitable fixtures, helps in accurate wall washing. This uniform illumination of the entire wall helps in hiding imperfections of artworks and also helps in elimination of shadows on the surface.
Wall washing with uniform illumination result the appearance of wall much clearer and brighter. It also helps in better enhancement of the architecture of the wall surface. Some of the lighting designers also believe that wall washing resulted into room as a whole look more lively ambience.
To achieve efficient and attractive wall washing effect, light fixtures are required to be mounted at or above ceiling height, so that light fixtures can effectively “wash” off vertical space. Light fixtures also need to be situated at sufficient distance from the wall surface so that the light can spread out at a wider beam angle. The light should be angled at eye-level or towards the centre of the feature or artwork.
It is always recommended and practiced by designers for using multi-directional light fixtures for wall washing. Such as usage of asymmetrical type light fixtures, help in attaining wall wash. Application of asymmetrical type light fixtures provides unidirectional illumination.
Wall washing is best used on walls which are having a flat, smooth surface to restrict shadowing. With the advent of LED light fixtures, flexibility offered by the well reputed manufacturers, help in attaining a uniform, shadow-free wall washing quality.
- Façade Illumination of a Villa and Building, completely designed by using DIALux Evo Software.
- Illumination resulting the wall grazing effect.
- Light fixtures are installed closer to the walls.
- Wall grazing is enhancing the shadows on the wall surface.
Wall grazing is another way of façade illumination of a surface which is opposite to wall washing effect. In wall grazing effect, the illumination of surface is non-uniform in comparison to wall washing.
Wall grazing helps to make textures vertical surfaces more noticeable or prominent by enhancing the shadows. By providing lighting illumination over the top of textures surface, wall grazing produces very noticeable or marked shadows to give the textured surfaces of wall more aesthetic look.
Wall grazing effect can be achieved by the providing the light fixtures closer to the wall in such a way that lux level depreciates as distance from the light fixtures. The light fixtures can be placed at the ground and focusing towards the upwards direction for mysterious, attractive or fascinating effects on the surfaces.
This methodology is generally used for illumination of statues. The shadow effects on the surface can be made more or less highlighted by the installation of light fixtures either closer or away from the wall surfaces.
Generally, it is assumed that façade lighting can be attained by providing illumination (either by fixtures with warm day light colour or RGBW colour). Selection of suitable light fixtures and their locations are very much crucial and critical for façade lighting design. Further, with the advent of LED fixture, flexibility is available in selection of type and colour of fixtures.
LED fixtures are energy efficient as well as have longer life in comparison to the conventional fixtures. LED fixtures provide flexibility in control of beam angle and its spread with much higher accuracy in comparison to the conventional light fixtures. Few parameters are discussed here which may help while façade lighting design.
- Selection of LED Manufacturer: LED wall washers shall be selected of a regular manufacturer. The brand is the guarantee of the people of confidence. Reputed manufacturers are providing guarantee of quality and are also ensuring responsibility of after-sales services. Further, reputed manufacturers are providing fixtures with CE/UL Marking which ensure the quality and certifications of the fixtures as per standards. With the usage of fixtures from reputed manufacturer, helps in maintaining the inventory of used products. Also, it seen that performance of fixtures manufactured with poor quality deteriorates at faster pace. Therefore, in the choice of LED wall washers or other façade fixtures, designer must choose a regular manufacturer, so that the end-users have more protection for themselves with respect to quality and after-sales services.
- Selection of appropriate LED fixture for wall washing / grazing according to the project area and distance: The throw distance is related to the lens and power. The higher the power, the brighter the projected brightness, and the narrower the angle of the lens, the farther the projection distance is.
Remember this point when choosing an LED wall washer. It is of worth mention that reputed manufacturers are having detailed photometric data of their products, which helps to understand the illumination level as well as beam angles. It is always best to let the manufacturer provide you with essential photometric data of their products. Further, façade illumination is outdoor type lighting design, hence the selected light fixtures shall be of appropriate IP Rating as well as IK Rating, so that the lighting fixtures can withstand the harsh and non-uniform environment. The Ingress Protection (IP) system is a globally acknowledged to indicate the degree of protection against the ingress of solid objects, dust and moisture into an enclosure. The IK rating is the degrees of protection provided by enclosures for electrical equipment against external mechanical impacts in accordance with IEC 62262:2002 and IEC 60068-2-75:1997. Generally, light fixture having rating IP66 and IK10 shall be preferred for outdoor illumination.
Also, usage of simulation software such as DIALux EVO, AGI32, etc. can be used by the designer for actual simulation of illumination level.
- Lighting Effect should as be decided as per actual situation/mood/ occasion: Light change effects such as RGB or RGBW and DMX512 control, DMX512 changes more widely, depending on the actual needs. Millions of colour combinations are created by using above mentioned fixtures and accessories. Lighting effect can be changed as per the occasions and mood of festivities.
- Installation Precautions: At the time of installation, the number of LED wall washers is also determined according to the actual length string number. For example, if your new house ceiling design also uses this LED wall washer, because he can change a variety of effects, you need to calculate how long the length of a circle needs to be connected according to each piece, is it a single change or the overall flow effect changes and so on. The flexibility with LED Fixtures provides the optimum usage for wall washers.
Façade lighting design in a word, a successful lighting engineering design can effectively increase the vitality of the city, make the citizens feel proud, and at the same time give visitors a beautiful night view of the city. A good night illumination of the landscape can not only effectively reduce the occurrence of traffic accidents, but also help maintain urban social security, and attract more customers to visit the commercial street. This plays a decisive role in establishing a commercial street and even a city image.
Er. Chaudhary Rajneesh K. Singh,
Deputy General Manager/Electrical,
Rail Vikas Nigam Limited, Lucknow