Last Updated: Jul 10, 2021
An abundance of natural light flooding into your home is obviously attractive and is a great way to reduce your residential energy consumption that comes with reliance on artificial light. However, while lighting technology such as LED bulbs has drastically reduced the amount of energy we use to keep our homes illuminated, we still used around 129 billion kWh of electricity to light our homes in 2017 alone. That is a lot of electricity and many carbon emissions that we are pumping into the atmosphere.
While turning off lights in rooms that are not in use is certainly one way to reduce the amount of energy our homes require, finding ways to allow natural sunlight to enter our homes during the daytime hours is another great way to reduce our dependence on artificial light. Residential tubular skylights are a step above regular skylights and offer a unique opportunity to brighten homes without some of the drawbacks of other skylight products.
The skylight in the bedroom nestled into the northern corner of your home most likely illuminates a room that would otherwise be dark and dreary during the long months of winter. However, that same skylight during the winter could result in an enormous amount of heat gain during the summer that negatively affects your home's energy performance.
Today's energy-efficient construction methods focus on super tight housing envelopes, and skylights are often recognized as a weak link in your home’s housing envelope. In some cases, the potential savings from reduced reliance on lighting could be overshadowed by heat loss or gain (depending on the season) that negatively affects your home's thermal performance. A study by the University of Dayton finds that “too many or too few skylights can increase net energy costs.”
Improperly installed skylights can also lead to leaks that could potentially cause significant damage inside the home. Even modern-day skylights that claim to be “leak-proof” can fail due to years of constant rainfall, snow runoff, and extreme temperatures. Also, in areas where heavy winter snowfall is common, skylights can cause ice dams that can ruin a roof while also causing heat loss through the roof.
A tubular skylight, also known as a “sun tube” or “sun tunnel,” is an alternative to larger skylights that allow you to flood a dark room in your home with natural light while avoiding some common pitfalls associated with regular skylights. A tubular skylight is a rigid and fixed pipe installed in your roof between 8 and 24 inches in diameter. These tubes are strategically placed to maximize the amount of natural light that can be captured and reflected into your home. In many cases, the interior part of a tubular skylight is made from a highly reflective surface such as polished sheet metal. This acts as a mirror to capture the sunlight at the apex of your roof and reflects light into your home.
Most tubular skylights also include a transparent dome cover on the roof that protects your home from the outside elements and a diffuser placed at the end of the tube where the light enters your home at the ceiling level. This diffuser is specifically designed to help spread the light throughout your home and is also covered with a special UV coating to protect the interior of your home.
Skylights might be larger than sun tubes, but that doesn’t necessarily mean that they let more light into your home. The strategic placement of tubular skylights along with the reflective interior and the diffuser often allow a 10-inch tube to produce the same amount of light as a massive glass skylight that required significant remodeling of your roof. In fact, a 14-inch tubular skylight can easily add natural light to brighten up to 300 square feet, which is the equivalent of four 100-watt bulbs. For windowless rooms such as bathrooms, laundry rooms, or large closets, an advantageously placed tubular skylight might allow you to do without artificial light during daylight hours.
Tubular skylights are much smaller than regular skylights, and they are also much more energy efficient. The dome's small size does not significantly compromise the building envelope and thus allows homes to avoid heat gain during the summer and heat loss during the winter. While some critics might point out that tubular skylights don’t offer much of a view, larger skylights only provide a view of the sky above, and very few people will spend long hours contemplating a square of blue sky.
Tubular skylights provide light that is primarily considered to be more natural than fluorescent and even LED bulbs. While tubular skylights will look like a standard lighting fixture, they provide warm light, which is beneficial for your health, while also helping people during winter months to avoid seasonal affective disorder resulting from a lack of sunlight exposure.
Tubular skylights are relatively small devices, and they are usually much less expensive than larger skylights. This lowers installation costs and can also make it easier to insulate. At the end of almost all tubular skylights, the light diffuser also contains a UV coating to help protect your furniture, wood or laminate flooring, and other interior design elements of your home.
Tubular skylight installation costs between $500 to $1,000 with an average of $800. This is less than half of the installation cost of a traditional skylight.
A small 10" solar tube can generate similar light to that of 3 15-watt LED light bulbs or the equivalent of 3 100-watt incandescent light bulbs. This is enough output to light a room up to 200 sq ft. Larger, 14" solar tubes are capable of producing nearly twice as much, lighting roughly 300 sq ft.
Solar tubes are ideal for any room in the house. You'll want to avoid installing solar tubes near computers or televisions as they'll produce glare during the day. Solar tubes are usually found in kitchens, bathrooms, bedrooms, home offices, hallways, laundry rooms, closets, stairways.
Solar Tubes are commonly available in lengths ranging from 6 meters to 9 meters but are available in several lengths. Longer tubes usually have a larger diameter to allow for more light. The rule of thumb is, the shorter and straighter the tube, the more light transfer.
Solatube is a company that offers tubular skylights that offer both lighting and ventilating opportunities for your home. You can purchase a solar attic fan from this company while you purchase a sun tube to reduce the overall cost of installation. Their innovative daylight-catching dome and integrated reflector bring an enormous amount of light into your home during all seasons of the year. You can find a local dealer that offers Solatube tubular skylights here.
Natural Light Tubular Skylights offers tubular skylight lighting solutions for both residential and commercial buildings. Their residential models are available in 10, 13, or 18-inch models. Depending on your specific needs, these tubular skylights can illuminate and mimic anywhere between 300 and 1,450 watts with the natural light of the sun. You can also find detailed step-by-step instructions for DIY installation if you prefer to install the skylight by yourself.
Elite Solar Systems Inc offers residential tubular skylights in 18, 21, and 24-inch sizes, making these some of the larger sun tubes on the market. If you have a dark room in your home that desperately needs an influx of natural light, these skylights might be the best option for you. You can find their nationwide distributors here.
Tobias runs an agroecology farm and a natural building collective in the mountains of El Salvador. He specializes in earthen construction methods and uses permaculture design methods to integrate structures into the sustainability of the landscape.