Tubular Daylight Systems (TDS)
Originally conceived by the ancient Egyptians, the principal of a light pipe is simple, collect daylight from outside and pipe it into a building that has little or no light from other sources. Fast forward five thousand years and the technology has moved on a little bit.
Modern plastics and hi-tech reflective materials now allow us to deliver natural light deep into the heart of buildings, opening up new opportunities for architects and designs.
However, with a dozen or more systems on the market and no common standard to allow for the performance of system to be judged against a competitor, how do building designers make an informed decision as to which system will deliver the required results?
Evaluating the Daylight System
The ability of a tube to transmit light will be determined by three factors; length of the tube, width of the tube and the reflective surface of the tube – the reflective value. Assuming that the length and width are the same, the tube with the highest reflective value will deliver more light than a tube with a lower value. And the difference of only 1% can make a significant difference over a couple of meters of tubing.
Likewise, compare a wide tube and a narrow tube (both with the same lining and length) and the wide tube will deliver more light as there will be less energy lost from the light bouncing off the tube walls.
So, as a simple rule of thumb, always select a system with the maximum reflective value to guarantee minimum light loss to ensure the delivery luminescence required. It is also important to specify the correct size and number of systems in order to provide the appropriate light levels for the building. Contact our technical team for information.
How much light can I expect from a Daylight Systems?
The amount of light delivered by a daylight system (taking on board the parameters discussed earlier) will be affected by two primary factors. Firstly, the location of the system on the roof, the distance the tubes need to travel to reach their destination and amount of daylight available. Secondly, the anatomy of the system; dome design, reflective value, width and length.
Whist it is unlikely that the first factor can be significantly altered, the second is something that a building designer or owner has a greater influence over. The make and model of Tubular Daylight System (TDS) that you choose for your project can make a massive difference to the amount of light that will be delivered into a building.
Solarspot® Daylighting Systems
Simply put, the Solarspot® tubular daylighting system is out in front when it comes to light delivery. The Solarspot system is designed to meet the varying weather conditions that we face in northern Europe. The dome and internal lens system are engineered to capture as much available light as possible, direct or ambient, without any artificial design barriers – as found in systems were the lens is moulded into the dome. The tubing is manufactured from the world’s most reflect tubing material. The flashing systems are designed to ensure a totally weather-tight junction with any roof type, regardless of climatic conditions. And a comprehensive range of sizes guarantees that there is a Solarspot system for you – whatever your project.
All Solarspot® systems ensure that whatever light is available, the maximum amount will be delivered to the space below. Whether you are specifying a 250mm unit for a corridor or bathroom or a 900mm system for an atrium, no other TDS will come close a Solarspot® for light delivery.
The dome and RIR™ Light Funnel
The dome system employed on all Solarspot systems is designed to ensure that the maximum amount of light enters the tube opening. The crystal clear dome is just large enough to house the RIRTM Light Funnel but small enough to minimise loss through ‘light bounce’ – the larger the dome in comparison
Unlike TDS that have lens moulded into the dome, Solarspot® uses a Fresnel lens – RIR™ Light Funnel – suspended within the tube opening. Domes with lenses moulded into the dome will actually restrict the light entering the tube.
This is a luxury that we cannot afford in Northern Europe. That is why the Solarspot® dome is designed to harvest the maximum amount of light from the dome and the lens is actually inside the dome to ensure that nothing escapes.
Convas® polycarbonate condensation control
All Solarspot systems specified for commercial roofs are supplied with a Convas® condensation control lens. The polycarbonate Convas lens is located at the top of the tube so that the Solarspot system conforms to UK building regulations. It also provides an additional thermal layer to ensure the system has excellent thermal values and meets the requirements for part L standards for daylight roof systems.
The Sun Tube
Vegalux® – advanced light delivery technology
All Solarspot systems employ tubing manufactured from Vegalux® – anodised aluminium sheets laminated with 3m Daylighting DF2000MA film, the most reflective tubing material in the world. At 99.7% reflectivity, no other technology will deliver as much light. And even though some competitor systems boast figures of up to 98%, in a typical installation, this could mean that 30% of the original light volume is lost, compared to around 6% in a Solarspot® Daylighting System.
In addition, all of the reflective value of our material is specular reflectivity. For systems quoting 98% or less, only around 92% will be specular reflectivity with the balance made up of diffused reflectivity. This means that in reality, a system bosting a 98% reflective value is probably nearer to 92%.
Flexible-duct systems would be delivering around 10% of original light – losing over 90%.
All of this may sound complicated but it’s actually quite simple; every time light bounces off a surface it loses energy (light). The more the light bounces (the longer and/or narrower the tube) combined with the light lost per bounce (dependent on the eflective value of the tube surface) the more light will be lost.
For example, if the light has to bounce 20 times to get from one end of the tube to the other then it will lose energy every bounce. With Vegalux® only 0.3% of the energy is lost on each bounce. The next best material, at 98%, will lose 2% (at best) each bounce. Over twenty bounces, that really adds up.
The illustration below shows how the different materials deliver very different levels of light
Vegalux extension tubes are available in a variety of lengths from 200mm to 1.2m. In addition, we produce a rage of angle adapters to ensure a hassle free installation.
Stylish and discreet, all Solarspot® diffusers are optically engineered to distribute light evenly whilst protecting against condensation and tube contamination.
There are a range of diffusers to suit virtually any build requirements; round or square, closed-ceiling diffusers for plaster board or solid ceiling, square diffusers for suspended ceilings and lamp-style diffusers for open ceiling environments.
Solarspot® manufactures a wide range of systems to ensure that there is a daylight solution for virtually every project. With five system sizes, 250mm diameter up to 900mm diameter, an extensive range of flashings and diffusers, you’re sure to find the right solution for your daylight requirements.