By REBECCA SLOAN
ay the word skylight, and most people will picture a square piece of tempered glass mounted in the ceiling of a room.
But say the words tubular skylight, and most people won't know what to picture.
What does it look like?
How does it work?
Why is it designed like that?
Alan Antol, of A.M. Door and Supply in North Jackson, is used to questions like these. Antol said tubular skylights, which are fairly new to the market, might seem a bit unusual, but they actually have several advantages over traditional skylights.
"Because they are smaller and more compact than traditional skylights, tubular skylights can be installed in cramped areas where traditional skylights won't fit. They also cost less, are more energy efficient, are easier to install and the flashing that goes around a tubular skylight is less prone to leaks," Antol said.
So what exactly is a tubular skylight?
A tubular skylight is a cylindrical shaped tube of "reflective light pipe" with a "collector" dome on the top that absorbs sunlight.
It fits vertically through a hole cut from the ceiling to the rooftop in much the same way that a stove or bathroom vent pipe would.
The interior of the tubular skylight is coated with a highly polished finish that reflects the entering sunlight.
A diffuser inside the tube then spreads the reflected sunlight evenly throughout the room, minimizing bright squares on carpets and eliminating unsightly fade spots on upholstery.
Although tubular skylights are smaller than traditional skylights, the diffuser spreads just as much light through a room as a larger-size, traditional skylight would.
However, since the sunlight entering the room is diffused, it has a gentle glow that looks softer than the light that shines into a room through a traditional skylight.
Since tubular skylights are compact, they can be installed in cramped spaces and in steeply pitched roofs.
And since tubular skylights can even be bent at varying angles, there is greater control over the direction that light enters a room.
"The place where the tube is bent is called an elbow. Elbows work well in rooms with steep pitches or situations where straight pipe applications aren't possible," Antol explained.
It is important to remember that each time light is "bent," there is a loss of light reflection.
To install a tubular skylight, attic space, or at least a small crawl space, is needed.
"That is one of the few drawbacks to these. You at least have to have enough space for a person to crawl in and do the installation," Antol said.
Installing a tubular skylight, however, is faster and easier than installing a traditional skylight.
"There is no drywalling or painting, and no framework is needed. Basically you just cut the two holes -- one in the roof and one in the ceiling -- and you install the unit. You just need a few basic hand tools like a jigsaw and a screw gun to hang the flashing," Antol said, adding, "This is a job that the do-it-yourselfer can do. You can install a tubular skylight in about half a day."
Since just one piece of flashing is used, the unit is less prone to leaks than it would be if several pieces of flashing were being applied.
Tubular skylights are more energy efficient than traditional skylights for several reasons.
They are weather-tight and will stand up to heavy snow and scorching heat. And since the light tube acts as a sealed shaft, very little heat escapes into the attic or into the room that it is illuminating. The diffuser also does its part in keeping cooling bills lower by minimizing the amount of direct sunlight that filters into the room.
Antol said tubular skylights also cost less than traditional skylights.
A 10-inch tubular skylight costs about $195, and a 14-inch costs about $300.
Antol said a 10-inch will illuminate about 150-square-feet of living space, while a 14-inch will illuminate about 300 square feet.