Tubular Skylights -- What Are They?

Tubular skylights allow sunlight gathered from a roof-mounted collector to reflect through a tube down into your living space. The reflective tube guides the sunlight to a diffuser lens mounted on the interior ceiling surface, spreading light evenly throughout the room.

Benefits

Cost: Some of these systems cost less than conventional lighting systems, and most cost much less than a conventional skylight. The retail price of a tubular skylight ranges from about $150 for small basic models to more than $600 for larger, deluxe models. The installed cost can be lower than conventional skylights because additional framing is not needed for installing in new homes, and fewer framing alterations are needed in existing homes.

Energy Savings: By utilizing the light from the sun during the day, considerable energy savings can be realized by not using electric lights. Because the rooftop light collector has a small surface area and because of the airspace between the collector and the diffuser, building heat loss in the winter and heat gain in summer are minimized.

[IMAGE: Tubular skylights reflect light through the attic into the living space below.]

Courtesy of Sun-Tek
Manufacturing

[IMAGE: View of hallway brightened by a solar tube]

Easy Installation: Installation is usually simpler than standard skylights and uses only common hand tools. In most installations, a hole the diameter of the reflective tubing is cut in the roof sheathing and interior ceiling. The self-flashing collector is mounted on the roof and the reflective tubing attaches to the collector and extends to the interior wall surface. The diffuser mounts to the end of the reflective tubing. The narrow diameter of the tube (between 10 and 21 inches) allows the reflective tubing to pass between roof rafters or trusses. The fixture's light weight allows it to be mounted on the existing roof and interior ceiling with no additional support. Manufacturers generally claim that their product can be installed in less than two or three hours.

Indirect Sunlight: Unlike traditional skylights, tubular skylights transmit indirect, diffuse sunlight that reduces potential UV damage to carpets and furniture. They also distribute light more evenly throughout a room (no harsh direct sunlight enters the room).

They Work: My father and I installed three solar tubes on my parents' home in Minnesota in one afternoon. We put one in a hallway (see photo above), and one in both of the bathrooms. Even around dusk, they provide enough light that you don't have to turn on the lights.

Daylighting Techniques

For more information on different daylighting techniques, view the PATH Lighting Tech Set. It also includes information on energy-efficient artificial lighting options.

[IMAGE: Roof mounted collectors are small enough to not be eye soars]