Light pipes – the facts
The performance of any Tubular Daylight System (TDS) is governed by a number of factors. These can be separated into two categories; product specification and the building specification.
Taking the latter first, this will be the dictated by the building design and location. The length of the tubes and the orientation of the domes on the roof will all affect the performance of the daylighting systems in the building and are usually restrictions that can not be changed.
The former however, will also have a huge affect on the amount of natural light delivered and this is where correct system specification is vital. In essence, the maximum light will be delivered from a short, wide TDS located on a bright aspect. Fine in a perfect world, but not always practical. That’s why it’s imperative for designers and specifiers to understand the differences between the various TDS systems available and which sizes are required to deliver the optimum daylight levels for their projects.
All TDSs are not the same. For example, Solarspot is not the only system to employ a tube system with a reflective value of 99.7%, what is not made clear however, is the effect the dome design has on the amount of light entering the tube. In fact, some domes with moulded lenses are actually designed to restrict light entering the tube at midday. This is fine for areas that are blessed with an abundance of sunlight – the Mediterranean or California – but of little use to anyone designing or living in a building in the UK. It also has a similar effect on cloudy days, actually blocking light into the system.
That is why Solarspot® systems employ a clear dome with a Fresnel RIR® Light Funnel located in the mouth of the tube. This innovative and unique solution ensures that the maximum amount of low-level light is harvested, capturing light on north-facing roofs, whilst providing a clear path for maximum delivery of over-head light – either direct sunlight or over-cast daylight. Couple these exclusive dome technologies with Solarspot’s Vegalux® super-reflective tubing and performance figures of up to 50% better than those of the best other rigid systems are easily achievable.
These patented technologies are standard across the complete Solarspot range of products from the compact D-25 system right up to the impressive D-90 unit.