Tubular Skylights

11/04/2011 by Paula Reale-Camelio

Skylights bring natural light into homes and offices, improving visibility and lifting our spirits. If you have a room or hallway you’d like to brighten up during the day without having to install or use electric lights, consider a tubular skylight.

What Is a Tubular Skylight?

Also known as a tubular daylighting device, a tubular skylight fits into small spaces where a conventional skylight would not. It consists of a small, durable plastic lens mounted on the roof and connected to a tubular aluminum shaft (usually 8 to 24 inches in diameter). It is connected to a ceiling-mounted diff user, a fixture that resembles a modern light fixture. Light enters through the lens or dome, is transmitted down the highly reflective tubular shaft, and is released into the living space via the diff user.

Tubular skylights work extremely well for a number of reasons. For one thing, the dome-shaped lens brings light in throughout the day, regardless of the sun’s angle. Another is the polished aluminum interior of the skylight shaft, which ensures maximum light transmission. Yet another is the diff user, which disperses natural light over a fairly wide area. Combined, these features enable tubular skylights to transmit a fair amount of light, even on a cloudy day.

Why Install a Tubular Skylight?

Besides brightening our homes, skylights provide natural lighting, which can improve our mood, enhance visibility, and make us more productive. Studies have shown that daylighting increases worker productivity and boosts test scores in school children, presumably by creating a more pleasant learning environment.

By reducing the need for electrical lighting during the day, solar tube skylights help cut electrical bills. On a sunny day, for example, the 8-inch DayLite™ skylight provides as much light as seven 100-watt lightbulbs. Their 12-inch model delivers as much light as ten 100-watt lightbulbs. Even on cloudy days, the skylights provide 100 to 180 watts of illumination.

Tubular skylights are widely in use in commercial spaces—for example, big “box” chain stores, factories, and warehouses, where they produce substantial savings on energy costs. In homes, they can also save money, especially when used in areas that require extensive lighting, like kitchens that have numerous high-wattage bulbs in recessed fixtures or track lighting. However, not all installations save tons of money. In fact, it could, in some cases, take many years to pay back the initial investment.

Because they’re so much smaller than conventional skylights, tubular skylights provide several key advantages, especially over the older-style skylights found in many homes. One is that they let far less heat in on hot summer days. This reduces the demand for air conditioning and keeps the home more comfortable at a lower cost. During the winter months, tubular skylights lose much less heat than conventional skylights, also saving you money. And of course, any energy savings help reduce our emission of the greenhouse gas, carbon dioxide.

Another benefit of these smaller skylights over conventional ones is reduced glare on computers and television screens—resulting in less eye strain and fewer headaches.

Because of their size, tubular skylights are much easier to install than conventional domed or dormer skylights. They can usually be installed without modifications to existing framing and, as mentioned earlier, can fit in spaces like narrow hallways and walk-in closets. Several companies manufacture tubular skylights equipped with supplementary electrical lights for nighttime use.


Installing a tubular skylight is a job for professionals or knowledgeable and skilled do-it-yourselfers. To determine if you can handle it yourself, check out the installation instructions from the manufacturer before you buy the unit (they’re often available online) and study them carefully. Hire a professional if you have doubts about taking on the work yourself. There are many companies that sell the units and provide installation.

To install a tubular skylight, you will need the installation kit that comes with the skylight (including flashing); a reciprocating, keyhole, or jig saw; a plumb bob; a utility knife; an extension ladder and step ladder; a screwdriver; nails; and safety glasses. You might also need wire cutters and insulation.

Excerpted from Green Home Improvement, by Daniel D. Chiras, PhD, available through RSMeans Exerpted from Green Home Improvement, available through RSMeans. http://rsmeans.reedconstructiondata.com/67355.aspx