Solar Tubes or Skylights: Which is the Better Choice?

When it comes to maximizing the amount of natural light in our homes….something precious here in the Pacific Northwest….skylights seem the obvious choice. But they come with a price – the cost to install them and with plenty of negatives from their energy inefficiency to the potential leaks. For many, they simply don’t provide enough benefits to justify installing them. For others, there is no practical way to install one to get light where they want it. 

Solar Tubes

Solar tubes use a small glass or acrylic dome to capture sunlight. That light is reflected through a sheet metal tube onto a diffusing lens in the ceiling of a room below. 

It’s a simple, yet effective design. The size of the dome and the tube determines the amount of light entering the room. The design of the diffusing lens helps control the light emitted. While solar tubes don’t provide the architectural benefits of a skylight, they eliminate many of the negatives while still bringing in plenty of natural light.

The benefits of solar tubes over skylights

Sunlight where you want it

A large attic space over a ceiling makes a skylight impractical. A room with a shaded roof-line means the amount of sunlight brought in by a skylight could be limited. 

A solar tube, with its flexible tube means the dome does not need to be installed directly overhead. While there will be a point of diminishing returns with more bends and length in the tube, solar tubes provide an opportunity to bring in light where a skylight cannot. You aren’t limited to a room with a ceiling directly below the roof.

It’s even possible, with the right interior design and layout, to get natural light to a lower level. 

With a skylight, once the sun is below a certain angle, the amount of light entering starts to drop off. The dome on a solar tube, light can enter at less direct angles increasing the amount of available sunlight. 

Less likelihood for leaks

It’s often been said that “It’s not if your skylight will leak, it’s when it will leak.” While better designs have helped, it’s how a skylight is installed that creates the real risk for leaks.

Whichever you choose, there will be a hole cut in your roof. With solar tubes, that opening will be significantly smaller. The opening will be easier to seal and less susceptible to leaks as homes settle and roofs flex.

The smaller footprint of the dome for a solar tube and its shape combine to minimize leaf and debris build-up and prevent water from pooling. There is less area for moss to grow and hold water. The risk further decreases with flush fit domes. 

Greater energy efficiency

Unlike skylights which directly allow sunlight into a room, solar tubes capture and diffuse light. With tubes between the roof and ceiling, there is an insulating effect. Smaller openings in both the roof and ceiling further limit heat transfer. 

With the ability to direct natural light to a smaller room or one without direct access to the roof, solar tubes can further decrease the need to artificially light a room – lower electrical bills. 

Beyond the benefits above, solar tubes tend to be budget-friendly with a lower cost to purchase and install. Installation is quicker with less mess so less disruption to your daily life. 

Solar tubes aren’t perfect

There are some downsides when compared to traditional skylights. 

• There is no architectural value from them and there is generally minimal return at resale. 
• They bring in light, but don’t make a room feel bigger.
• You don’t get a view of the sky.
• They aren’t suited for all roofs – Most solar tubes are designed for roofs with a slope between 15 and 60 degrees. A steeply pitched roof may make installation impossible. 

Solar tube or skylight?

Ultimately the choice is yours, but if your goal is more light, solar tubes offer greater flexibility at a lower cost, greater energy efficiency, and a lower risk of leaks. 

Either way, we still recommend a routine inspection and maintenance schedule. 

Featured image credit: Mimi Kotter, CC BY-SA 3.0, via Wikimedia Commons