People looking to lower their electricity bill need to add a sun tunnel or a tubular skylight to their homes, as by using the sunrays to light up your homes, you can save money by switching off the electric lights. A 10" reflective tube provides natural light of about 3750 lumens, much more than a 100w light bulb even on a cloudy day.

The sun tunnels work on the principle of taking the sunlight, coming from all directions, by a dome that is put on the roof. The sunlight is directed into a reflective tube made of aluminium, which has a reflective surface of very high reflection coefficient. The rigid and flexible sun tunnels have a dual diffuser that reduces the chance of condensation and increases energy efficiency while providing even light distribution through a frosted diffuser. A sun tunnel features a ring with a mirror finish just below the dome to reflect light from all angles into the tube.

Many factors affect the transmittance of the amount of light such as direction of Sun, orientation of roof, time of the day and season of the year, length and angle of the reflective tubes. The rigid shaft sun tunnel offers up to 3 times the light in a room than the flexible shaft model, because of the fact that the loss of light is minimal in the process. The amount of sunlight transmitted will be the most during noon and on a sunny day for both kinds of tubes.

Flexible tubes are available in 14" or 21" sizes with the flexible tubing that allows the unit to go around virtually any attic obstructions beyond the reach of rigid tubes, and provide sunlight to the otherwise inaccessible areas. The rigid tubes are available in 10" or 14" sizes, though are nearly as bright as a 21" flexible tunnel and give the greatest light dispersion and brightness. The highest individual transmittance recorded for a flexible tube stretched was 6.8%, which was less than one sixth of that for the rigid tube. The rigid sun tunnel is suitable for places which require direct and longer tunnel length, especially great for those areas with less sunlight or the North facing roofs, giving 98% reflectivity.

You can install both the tubes on roofs with slopes between 15 degree and 60 degrees, and the installation process requires only basic carpentry skills.