It's hard to find a new house without at least one skylight. While skylights have many advantages, they can be expensive, they can capture unwanted heat during summer months and sometimes they just don't fit.
SolaTube, a product recently imported from Australia, overcomes these limitations. It can bring natural light into dark interior spaces, without overheating. It's also considerably easier and less expensive than a skylight installation.
Think of the SolaTube as a light pipe. The main element is an uninsulated, 10-in. diameter aluminum tube. The inside surface is coated with a reflective mirror finish. The tube extends through the roof, where it's covered by a durable plastic flashing and a clear acrylic dome. A small reflector helps direct light down the tube.
Inside, the tube ends at the ceiling surface, where it's covered with a diffuser that spreads light across an area that's about 10 ft. x 10 ft. The top and bottom pieces of tubing are adjustable to accommodate different ceiling and roof slopes. Extension tubes are available for longer runs, although overall tube length greater than 4 ft. is discouraged.
The light from SolaTube has a slightly bluish cast. It's best suited to areas with no other source of natural light. The obvious locations are bathrooms, hallways and walk-in closets.
Energy-efficient builders may want to wrap insulation around the tube and place a gasket around the interior ceiling ring and diffuser.
The entire arrangement takes about two hours to install. It is approved by the International Council of Building Officials (ICBO) and carries a 10-year limited warranty.
This article appeared in Energy Source Builder #37 February 1995