Commercial Tubular Skylights for Fast, Cost-Effective Daylighting

For adequate daylighting, big commercial buildings require big commercial skylights, right?

Not necessarily.

VELUX Commercial Sun Tunnel® Skylights provide an efficient, cost-effective way to bring natural light into interior spaces where a traditional skylight may not be the right fit. Designed for commercial buildings, these tubular daylighting devices capture sunlight at the roof and direct it through a highly reflective tunnel to the space below.

With a long-term reflective performance of 99% and a 20-year rigid-tube reflective warranty, VELUX Commercial Sun Tunnel Skylights can help deliver bright, clean daylight into workplaces, warehouses, schools, retail spaces, medical facilities, and other interiors that need daylight without a direct view to the outside.

What are Commercial Tubular Daylight Devices?

Commercial tubular daylight devices, or TDDs, are daylighting systems that use a rooftop dome, a reflective tunnel, and a ceiling diffuser to direct daylight from the roof into the building interior.

Instead of relying on a large glazed opening or a traditional light shaft, a Sun Tunnel skylight uses a compact tube system to efficiently deliver daylight through the roof assembly and ceiling space. This makes it a practical solution for large commercial buildings, especially where daylight is needed in interior areas, corridors, workspaces, storage areas, or open-ceiling environments.

Where to Install VELUX Commercial Sun Tunnel Skylights

VELUX Commercial Sun Tunnel Skylights are designed for spaces that need daylight without requiring a view to the outside. They can be installed in both open- and closed-ceiling applications and are especially useful where a cost-effective daylighting solution is needed.

Ideal applications include:

• Schools
• Retail spaces
• Medical facilities
• Warehouses
• Service bays
• Open-ceiling commercial spaces
• Interior areas where natural light is limited

Compared to traditional on-site-constructed light shaft solutions, VELUX Commercial Sun Tunnel Skylights can offer greater cost savings as the light shaft length increases.

Different VELUX Commercial Sun Tunnel Models

VELUX Commercial Sun Tunnel Skylights are available in multiple model types, dome options, and flashing configurations to support different roof conditions and project needs.

TGC: Self-Flashed Model

The TGC model is a self-flashed option available in 14" and 22" sizes.

Key features include:

• Low-profile pan flashing
• Flexi Loc™ tube system
• 16" tube extension
• Available with low-profile dome or high-profile SunCurve dome
• Roof pitch: 0°–60°

TCC: Curb Mounted Model

The TCC model is designed for curb-mounted applications and is available in 14" and 22" sizes.

Key features include:

• Low-profile curb-mount flashing
• Flexi Loc™ tube system
• 16" tube extension
• Available with low-profile dome or high-profile SunCurve dome
• Roof pitch: 0°–60°

TMC: Pitched Self-Flashed Model

The TMC model is a pitched self-flashed option available in 14" size.

Key features include:

• Lower profile dome
• 20° pitched pan flashing
• Flexi Loc™ tube system
• 16" tube extension
• Roof pitch: 14°–60°

The SunCurve Dome

One of the most important performance features of VELUX Commercial Sun Tunnel Skylights is the SunCurve dome. The VELUX SunCurve is designed to capture sunlight that would normally pass through the dome and redirect it down the tube. It comes standard on every 22" Commercial Sun Tunnel Skylight.

Here’s how the SunCurve helps improve daylight capture throughout the day:

• Morning light: Captures low-angle sunlight and curves it down the tube.
• Mid-day light: Helps manage intense, direct sun so the space below stays bright and comfortable without glare.
• Afternoon light: Captures low-angle sunlight later in the day and redirects it into the tunnel.

Tall and low-profile dome options are also available, with acrylic impact-modified and polycarbonate impact dome options, depending on project requirements.

Quick Assembly with Flexi Loc™ System

Each VELUX Commercial Sun Tunnel uses the Flexi Loc™ tube system, designed to simplify assembly and support faster installation. The system helps connect elbows, tube extensions, and other rigid tunnel components more efficiently than conventional screw-based connections.

This makes Sun Tunnel Skylights a practical option for projects that need repeatable installation across multiple daylighting locations, especially in larger commercial spaces.

Looking for product details or installation support? Access our technical resources, including CAD files, BIM models, installation instructions, and ordering guides.

Diffuser and Ceiling Options

VELUX Commercial Sun Tunnel Skylights offer several diffuser assembly options to match different ceiling conditions:

• THC: Hard ceiling assembly for drywall applications
• TTC: Round-to-square assembly for suspended ceilings
• TOC: Open ceiling assembly

Diffuser material options include:

• Frosted: Balances performance and aesthetics
• Prismatic: Provides good light distribution with a familiar commercial ceiling appearance
• Fresnel: Uses a concentric parabolic prism pattern for enhanced light diffusion

All diffuser options are available in 14" and 22" sizes.

Accessories and Performance Options

VELUX Commercial Sun Tunnel Skylights can be customized to support a range of project needs, from installation flexibility to daylight control, energy performance, and added protection. Accessories are available to help adapt the system to different ceiling conditions, roof layouts, and performance requirements without complicating the overall design. For projects with specific energy goals, optional Energy Kits can also help improve U-factor performance across diffuser types.

Planning a Commercial Daylighting Project?

Every building has different daylighting needs. Whether you are planning for a warehouse, school, retail space, medical facility, or another commercial application, the VELUX Commercial team can help you evaluate product options, sizing, installation conditions, and project-specific requirements.