An introduction to daylight products
Daylights are products that allow sunlight into the building without any heat. The daylights are basically of two types, one is tubular type popularly known as lightpipe or solar pipe and the other is prismatic daylights usually known as Norikool daylights.
Lightpipes
The lightpipes transmit the sunlight collected outside the building into it through a tubular arrangement. The lightpipe consists of three major parts listed below.
- Light Collector
- Reflective System
- Light Diffuser
LIGHT COLLECTOR
The light collector collects sunlight from all directions and delivers light effectively through out the day even at low sun angles. Since the collector can collect sunlight even at a low angle, the light collection in the mornings and evenings are boosted. The lightpipe delivers more uniform light throughout the day, while partially rejecting mid noon sun radiation and blocking UV radiation.
Lightpipe – Sunlight Capture System
S.No. Parameters Specifications
1 Sunlight Collector Cover The Transparent, Clear dome allows light to be
collected across the sky from all directions.
2 Shape It should be moulded, Single Piece, dome
shaped.
3 Material Clear, transparent polycarbonate.
4 Thickness To be formed out of 3mm thick clear
polycarbonate sheet.
5 UV coating thickness for Raw
material sheet80 Microns
6 UV Block Upto 99% (UV A&B)
7 Impact Strength 600-800 J/M (ASTM D256)
8 Flame Redundancy Limiting Oxygen index LOI -25(ISO 4589 ASTMD 2863)
9 Light Transmission 83% Test Standard
10 Heat Resistance Temperative 45º – 150º Celsius (DIN 53460)(VICAT VST/B)
11 Thermal Conductivity 0.21 /m0c (DIN 52612)
REFLECTOR SYSTEM
The reflector system delivers high luminance without colour shift even on cloudy days. The reflector is mirror finished. The reflector also called light transfer system comes in four different diameters viz., 300mm, 400mm, 530mm and 750mm. Below is a specification of a 530mm lightpipe transfer system. The specification of other diameter lightpipes is also almost similar.
Lightpipe – Light Transfer System -530mm
S.No. Parameters Specifications
1 Diameter 530 mm
2 Shape Cylindrical Shape
3 Material Aluminum
4 Total Reflectivity 98%
5 Material Thickness Not less than 0.4 mm
6 Protection Film PE foil not UV Resistant
7 Bends (in degrees) 90 & 45
8 Universal Roof adopter Two piece, adjustable, universal roof adopter of
standard length (570mm – 600mm)
9 Adjustable angle 0° – 30° pitch angle of roofs. For angles above 30°,
customer to specify
10 Diameters To match LPR 530mm
LIGHT DIFFUSER
The diffuser spreads the light into the building minimizing the glare and with comfort to humans inside the building. To give a pleasing light, the diffuser is categorized into three types, viz., clear bright, soft white and bright vision. Read the selection guide to find out the suitable diffuser for your application.
Lightpipe – Light Diffuser
S.No. Parameters Specification
1 Shape It should be moulded, single piece flat/ Dome Shape (like a flat
bowl) for better distribution of light.
2 Material Polycarbonate Clear Bright Prismatic or Pigmented Soft White
3 Thickness To be formed out of 2mm Thick material.
4 Light
TransmissionNot less than 80%.
5 Diffuser Ring Injection molded ABS plastic ring – white color.
6 Double
GlazingDiffuser double glazed with 1.0mm thick clear polycarbonate with
90% Light Transmission.
7 Diffuser to
pipe fixingLocking provision of pipe into the diffuser ring with silicon seal.
Lightpipe – Diffuser Selection Guide
The diffuser is the lower most part of the lightpipe through which the sunlight is distibuted into the building, It is of three types namely, clear bright, soft white and bright vision.
Parameters Clear Bright Diffuser Soft White Diffuser Bright Vision Light Diffuser
Light High light transmission Soft, pleasing light High light transmission
Light Distribution Medium light Distribution High lighting distribution Controlled light distribution
Roof Height Applicable for high roof Applicable for low roof Applicable for high and medium roof
Application Industries and Warehouses Offices and Residences Commercial
buildings, Warehouses, Industrial
Buildings and Offices
Shape Dome Shape Dome & Flat Shaped Flat shaped
Image 
LENGTH AND DIAMETER OF THE LIGHTPIPE
The lightpipe comes in different diameters and length. The below table gives an overview.
Lightpipe Selection Guide
The selection of lightpipes basically depends on the roof height and the lumen required.HEAT TRANSFER
The lightpipe minimizes the heat transfer . The high performance light collector partially rejects the mid noon sunlight thus effectively rejecting any additional heat. The static air column in the reflector system does not allow heat to be transmitted.
Some photos from installed sites
click on the image to zoom
Prismatic Daylights @ Norikool
Norikool is an Advanced Daylighting Solution for Industries & Buildings, that can replace Strip/Roof lights in Industries and Pre-engineered Metal Buildings. It delivers exceptional daylight with negligible or minimal heat transfer. It can replace Strip/Roof lights in. Unlike traditional translucent sheets, norikool is easy to install and maintain. The heat transfer is very less, while the transmission and distribution of light is very much better than those in traditional translucent sheets.
It is made of polycarbonate sheet with several minute prismatic structures. It comes in two sizes 1.2m x 1 m and 0.6m x 0.4m. It is installed in three different types of glazing viz, single, double and triple glazing.
The selection guide to choose the right norikool is given below.
Norikool Selection Guide
Norikool is ideal in cases where there is an open ceiling. As norikool does not have any part of it protruding inside the buildings, the lights will be obstructed if there is a false ceiling. Like lightpipe, the choice of Norikool also depends on the height of the roof and the required lumen.
HEAT TRANSFER
Norikool occupies very less space when compared to traditional skylights thereby allowing negligible amount of heat inside the building. A detailed case studies on heat transfer by norikool can be read here.
Some photos from installed sites
Click on the image to zoom
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