Solatube® Daylighting Systems – unrivalled performance
The performance of a Solatube® Daylighting System – indeed any tubular daylighting device – is relevant to external sky conditions and light levels; the brighter the day outside, the more light you receive inside. The key is to choose the system that makes the most of the available daylight throughout the day and this is where Solatube® Daylighting Systems lead the field.
This has been verified by recent testing carried out by two authorities; the Building Research Establishment (BRE) and the British Board of Agrément (BBA). This comprehensive testing provides accurate, reliable and above all independent performance data for Solatube® Daylighting Systems and – in the case of the BRE – comparative data when tested against other tubular daylighting devices.
Whether you want to introduce daylight into an internal bathroom or pipe daylight over 22 metres into a commercial building, Solatube® will deliver unrivalled performance.
The superior efficiency of Solatube® Daylighting Systems
The theory is simple; actively collect the most daylight possible at roof level, ensure the maximum amount of light possible continues to the area to be lit, and, once there, diffuse the light effectively. Solatube® Daylighting Systems incorporate various technologies to ensure optimum performance at all times:
ACTIVE DAYLIGHT HARVESTING
Solatube® dome technologies ensure that the most light possible is collected at roof level.They do this by means of the patented LightTracker™ reflector and/or patented Raybender® 3000 Technology Fresnel lens system in the dome.
The LightTracker™ reflector is particularly effective during the winter months, early morning and evening when the sun is low in the sky, as it is ideally positioned to reflect and redirect the low angled light into the tube at a steeper angle of incidence – light that would otherwise have passed straight through the dome and been lost.
Patented Raybender® 3000 Technology consists of a series of Fresnel lenses positioned at critical locations inside the dome that light is directed into the tube at a steeper angle of incidence to minimize light loss.
The technologies in the Solatube® roof domes actively work towards getting more light into the tube at the steepest possible angle and can more than double the amount of light entering the tube over a passive dome or flat roof panel system that does not have these features.
TRANSFERRING THE MOST LIGHT POSSIBLE
While the angle of incidence is determined by the direction and angle of light entering the tube aperture, the tube material is a function of specification. Solatube® Daylighting Systems use the most reflective rigid tube material of any tubular daylighting device on the market today – Spectralight® Infinity. This material is 99.7% reflective, it is used on all reflective surfaces within the system, and is produced exclusively for Solatube® Daylighting Systems. The reflective properties of the tube material play a huge part in providing the best light transfer. 
As the chart (right) shows, a seemingly small difference in reflectivity value can make a substantial difference to the overall light delivery of a tubular daylighting device after just twenty bounces of light. When longer tube lengths are specified, a high tube reflectivity is even more vital to good light delivery.
DIFFUSING THE LIGHT
A uniform and even distribution of light is important when considering spacing criteria and number of systems to be specified. Solatube® diffusers not only distribute light evenly, they also contribute towards preventing solar heat gain/loss. Solatube® offers a range of diffusers for all ceiling types - for drywall or suspended ceilings, for open ceilings - as well as a range of diffuser lenses and trims.
