We asked BRE, an independent and impartial, research- based consultancy, testing and training organisation to test and compare three systems currently on the market- our Solarspot D-38, the Solatube 290DS and the Sunpipe 450. There are many, many different models, systems and sizes available but it would be impractical and impossibly expensive to test them all, so we picked the best selling rigid systems.
All three of the systems were just over 2mm long and the tests were performed on a naturally overcast sky- the typical British weather! Each of the systems were checked three times to ensure there were no sudden rises in the light or freak results.
The results were clear to see. Our Solarspot D-38 system was much more efficient at reflecting light than the SunPipe by almost half, which in turn was slightly more effective than the Solatube. The Solarspot D-38 is a more effective system for delivering higher levels of light, with the other two systems delivering half as much.