Sunshine from a Tube!

Like many sustainable home products, natural light tubes have been around for over 20 years but are still not widely accepted.  These tubular skylights have a number of different names, mostly derived from the maker’s identity, Sun Dome being the most commonly used name, when in fact this name is actually the company Sun-Dome. Other names include Sun Tunnel by Velux, Sun-Tek and Solartube are other manufacturers of these natural light tubes.

The reasons for using these are simple, as one company quotes ‘’they provide light without the need of constant electric light and with a lot more consistency than a window or a skylight’’ You can supply natural light to a small room easily, like a bathroom. They cost less than a skylight, their installation is very simple and they can be installed just about anywhere to create natural light. One survey I have stated that a skylight will add about $20.00 per square foot of glass in energy costs annually vs. less than a dollar for a tubular skylight.

Tubular skylights are designed to collect low angle light and redirect it to the diffuser which sends the light to every corner of the room.  Solatube has a prismatic lens that will illuminate up to 300 square feet from a standard 14’’ tube.  All of these light tubes have a dome lens on the roof, usually constructed of an optical plastic like acrylic or polycarbonate. This dome is fitted to the actual metal flashing that sits on your roof. Either rigid or flexible tubing is them attached to this dome inside your attic and directed to the desired room. Due to the reflective material that they coat the inside of this tubing with you do not need a straight path of light. The dome collects light that ‘’bounces’’ down the tube sending natural light to the room.

Skylights generate a lot of heat, especially in the cavity they are located in which explains why skylights have a checkered history for longevity and remaining watertight over time, not so with a tubular skylight. Skylights are notorious for leakage.

Velux, one of the largest skylight manufacturers recognized some of the skylight shortcomings and brought out an updated design a few years ago to answer some of these issues.   

Because conventional skylights are flat they don’t provide as much light, unless the sun is directly overhead. A test on a 14’’ tubular sun tunnel found that it could generate as much light as 5 incandescent 100 watt light bulbs. The savings are obvious, reduced use of electricity in household lighting. Some makers offer light dampers which allow them to be installed in bedrooms, a couple offer energy efficient lights within the tube to add to the artificial light in a home by utilizing the prismatic ceiling lens.

To meet the ‘’EnergyStar’’ rating these sun tunnels have a frosted dome that is designed to face down the roof. Most have a ceiling trim ring where you can paint this ring to match the interior ceiling.

I have recommended well over 100 of these sun domes during my time in the trades. They supply constant light in a seniors townhouse complex we built,  a corridor in one commercial building we were involved in found that they rarely uses the artificial light in their hallway. In over a dozen homes that I have been involved in directly or indirectly over the years have this excellent natural light source.

They are not unreasonable in cost; installed prices can be as reasonable, a 1000.00 is not an uncommon cost.   Compared to a skylight which commonly run over 2500.00 to install and I have heard of retrofitted prices closer to double that.  The fact sun domes are more energy efficient, have less heat gain and some now have light kits available they are worth considering if you have a need for some natural light added to a room or hallway in your home. Sun tubes are worth a look.