What’s the Difference Between a Skylight and a Sun Tunnel?

What’s the Difference Between a Skylight and a Sun Tunnel?

If your home is dark inside and the windows don’t bring in enough natural light, you might consider adding skylights. Placing openings on your roof brightens the room and can lower your energy bills. But there is no one-size-fits-all solution. Skylights are preferable in some cases, whereas sun tunnels are better options in other situations.

Skylight vs Sun Tunnel

Increasing the amount of light in your home isn’t always as simple as adding a window. Some rooms don’t have exterior walls, and the only option for an opening is on the roof. Skylights and sun tunnels are openings in your roof that are protected from the elements and allow natural light to enter the home.

Most people are familiar with the flat planes of clear glass, acrylic or polycarbonate that characterize a skylight. These act like windows on the roof, letting in natural light and expanding your view of the sky. Sometimes, they open to increase the airflow inside.

Sun tunnels, sometimes referred to as solar tubes, look more like a light than a window. They draw light into the room via a dome that’s installed on your roof. The dome captures natural light. The reflective surfaces and lenses within the tubing send the light to an opening in your ceiling.

A sun tunnel consists of a dome on the roof that captures and focuses natural light. A reflective tube channels the light to the lens in the ceiling. That lens diffuses the light into your living space.

Solar tunnels can have a rigid tube that travels straight to the roof from the opening in the ceiling. They have flexible tubes when an obstruction makes a straight path impossible.

Benefits of Skylight vs Sun Tunnel

One of the main advantages that a skylight has over a sun tunnel is the ability to see the sky through the window. Skylights are usually no smaller than 12 square inches, giving you visual access to the stars at night and ever-changing views during the day. This design can create an atmosphere of spaciousness in a home with low ceilings or windowless rooms.

If ventilation is important to you, skylights are a better option than solar tubes. You can install skylights that are fitted with screens to let the breeze in without inviting debris and critters into your home.

Differences Between Skylights and Sun Tunnels

Skylights and sun tunnels have different designs, installation methods and functionality. Sun tunnels have smaller openings than skylights and can be added to ceilings that don’t offer direct access to the roof.

Their design prevents sun tunnels from offering a view of the sky. Solar tubes are also a closed system; they don’t offer ventilation.

Snow accumulation limits the amount of light that gets through either type of skylight. Therefore, you’ll lose some of the benefits during winter storms. If you live in an area with extreme temperatures, you may want to opt for glass skylights, which are more durable than acrylic ones.

Traditional skylights are more appropriate for certain situations. But some of the other differences between skylights and sun tunnels put the solar tubes at an advantage.

Installation Cost and Complexity

It costs less to install solar tubes than traditional skylights. That’s because traditional skylights require meticulous carpentry, which increases the labor costs. Installing regular skylights also involves drywall and painting work. Solar tubes can be installed in about two hours and cost about half as much to install as traditional skylights. Regular skylights can take up to a a week to install.

Energy Efficiency

Because of their large surface area, skylights transfer more heat into your home than solar tubes. This can help keep your space warm in the winter. However, it may lead you to run your air conditioning more frequently in the summer.

The way that the sunlight is diffused within sun tunnel results in a brighter space with less heat transfer. This option allows you to keep the temperature inside your home more stable.

Dealing With Condensation

Condensation can be a concern with both types of skylights. If the skylights were installed properly, they are probably not to blame. Excess humidity in your home is often the culprit. Using a dehumidifier prevents condensation on traditional skylights.

To combat this problem in sun tunnels, the installer will wrap insulation around the tubes. A reputable installer will also use the proper flashing and seals to prevent moisture problems.


Sun tunnels are small and unobtrusive. They also require less maintenance than skylights. Traditional skylights require regular cleaning and inspections to reduce debris accumulation. Sun tunnels’ domed shape allows dust and other particles to slide off.

Which Option Lets In More Light?

Traditional skylights allow light to flow in naturally. Sun tunnels direct and diffuse the light. The amount of illumination that each option provides depends on the location and weather.

In an enclosed space, like a hallway or laundry room, adding natural light via a sun tunnel may be the only option. It reduces your reliance on electric light sources in those areas. In a larger area that has better access to the roof, a traditional skylight might bring in more light.

Placing a skylight in a shady area, such as under a tree, will limit the amount of light that gets inside. Neither sun tunnels nor traditional skylights allow much light to enter at night. But the sensation that you get when you can see the stars from your couch is only possible with a traditional skylight.

Unless they feature UV-blocking materials, traditional skylights let in more UV rays than sun tunnels. The light from regular skylights can damage furniture and surfaces inside your home. Solar tubes reduce UV exposure within the building.

Are Skylights or Sun Tunnels Right for You?

Consulting with an experienced roofing contractor or skylight installer will help you make the best decision for your space. Consider the advantages and downsides of each option, taking your budget and maintenance costs into account. No matter which option you choose, go for a high-quality product and an experienced installer to protect your roof and maximize the lifespan of the skylight.

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