Frequently Asked Questions
FAQ List

Q: What is the LightLouver Daylighting System?

A:

The LightLouver Daylighting System is a passive optical side-daylighting device that is positioned inboard of  the “daylight” window which redirects incident sunlight upward and deep into the daylit space while eliminating glare and any direct sunlight penetration onto work surfaces. The result is an ambient source of daylight made accessible to interior spaces that would otherwise be dependent on electric lighting. The heat associated with the redirected daylight stratifies against the ceiling and out of the occupied space, reducing the requirement for mechanical cooling as well.

For more information view the LightLouver Description

FAQ List

Q: Is the LightLouver Daylighting System a Light Shelf?

A:

The LightLouver Daylighting System constitutes a significant improvement over a traditional interior or exterior light shelf. Each reflective slat in a LightLouver unit performs the same function as a light shelf, but with improved performance. By adding a patented optical geometry and a highly specular reflective surface to the light shelf concept, a greater percentage of daylight is redirected much deeper inside a building than previously possible by a light shelf while eliminating glare. By miniaturizing the optical design concept into small reflective slats and stacking them into a "daylight" window treatment, total solar control is achieved, meaning no uncomfortable direct sun glare and reduced solar heat gain.

For more information view the LightLouver Description

FAQ List

Q: Can I use the LightLouver Daylighting System in my building?

A:

The LightLouver Daylighting System has been developed for commercial and industrial (non-residential) buildings and can be applied to any window that receives direct sunlight, provided that the bottom edge of the LightLouver unit is at least 7' above finished floor height.  Also, the visible light transmission of the window glazing should generally be above 60 % in new buildings and above 50 % in existing buildings. LightLouver units work best with a highly reflectance ceiling ( > 80 % reflectance  minimum ).

For more information view the Design Integration Guidelines

FAQ List

Q: How much light do LightLouver units provide?

A:

The LightLouver Daylighting System provides an annual average illuminance of approximately 20 to 30 foot candles, 30" above the finished floor within the daylit zone created. The daylit zone created is 14' deep for each vertical foot of LightLouver unit installed. For example, an application of 2 foot high LightLouver units will create a daylit zone that is approximately 28' deep.

For more information view the Illuminance Contribution and Design Integration Guidelines

FAQ List

Q: Can LightLouver units be used in a retrofit application?

A:

Yes! Because the LightLouver Daylighting System is lighter and easier to install than most other daylighting options, it is the perfect option for daylighting and energy efficiency retrofit projects.

For more information view the Design Integration Guidelines for Existing Buildings (PDF)

FAQ List

Q: How are LightLouver units installed?

A:

LightLouver units are mounted on support brackets which are attached to the window frame. The geometry of the brackets is such that the LightLouver units cannot be unintentionally dislodged, but can still be pivoted 2 to 45 degrees to allow easy cleaning of the daylight windows behind the LightLouver unit.

FAQ List

Q: What facades can I apply LightLouver units to?

A:

LightLouver units can be used in "daylight" windows on east, south, and west-facing facades in northern latitudes.  LightLouver units are an excellent choice for east and west facades, where sun angles are low, because of the unique optical design of the LightLouver reflective slats redirects all sunlight above a 5° solar altitude angle upward onto the ceiling. 

For more information view the LightLouver Description

FAQ List

Q: How much do LightLouver units cost?

A:

The LightLouver Daylighting System costs approximately $2.50 to $3.00 per square foot of daylit floor area. Or calculated as a function of LightLouver unit area, the cost is approximately $40.00 / sf  (i.e. a 5 ‘ wide x 2' high LightLouver unit would cost approximately $400.)

For more information view the Comparative Normalized Costs

FAQ List

Q: Can the LightLouver Daylighting System be used in existing buildings?

A:

Yes. The LightLouver Daylighting System can be used in existing buildings as long as:

  • Windows have access to the sun and are not shaded by obstructions such as overhangs, trees, or other buildings.
  • Windows are not darkly tinted. Windows can be tinted, but should not be extremely dark. Visible light transmission should be at least 40%.
  • Windows must be tall enough so that the bottoms of the LightLouver units are at least 7’ feet above the finished floor.  This is necessary so that sunlight is not reflected directly into building occupant eyes.

A screening tool is available on the web site to determine if an existing building is a good candidate for application of The LightLouver Daylighting Daylighting System.

For more information view the Design Integration Guidelines for Existing Buildings (PDF) and  Feasibility Checklist for Existing Buildings (PDF)

FAQ List

Q: Can LightLouver units be used to solve glare problems in an existing building?

A:

Yes.  LightLouver units are frequently used to solve glare problems caused by windows, clerestory windows or light shelves.

FAQ List

Q: Do LightLouver units increase the heat gain to the building?

A:

No.  In fact, the heat gain to the building is decreased because LightLouver units provide five times as much illumination per watt of heat as most electric lighting systems.

FAQ List

Q: Can LightLouver units be used to solve heat and glare problems on west-facing windows?

A:

Yes.  LightLouver units can be installed above conventional window treatments ( mini-blinds or shades ) to eliminate glare while redirecting sunlight upward onto the ceiling, allowing the electric lights to be turned off.

FAQ List

Q: What do I have to do to maintain LightLouver units?

A:

To maintain good performance, LightLouver units should be dusted once or twice a year, typically as often as the window behind the LightLouver unit is cleaned.  LightLouver units pivot at the top so that the “daylight” windows behind the units can be cleaned. LightLouver units have been installed in buildings throughout the U.S. since 2001 and cleaning and maintenance of the LightLouver units has not been a problem or a large maintenance cost.

For more information view the LightLouver Maintenance Manual

FAQ List

Q: How hard is it to mount LightLouver units?

A:

LightLouver units are very easy to install, typically taking less then 10 minutes per unit.  Support brackets are attached to the top of the window frame with two self-tapping screws per bracket. Then the horizontal header of the LightLouver unit slips into the brackets and locks into place.

For more information view the LightLouver Installation Manual

FAQ List

Q: Can I get help with integrating the LightLouver Daylighting System into my building?

A:

Yes, LightLouver LLC staff are pleased to offer LightLouver Daylighting System design integration assistance services to ensure the proper and effective inclusion of LightLouver units into your new or retrofit construction project. The services offered are as follows:

  • Daylighting Design Assistance
  • LightLouver Unit Integration Assistance
  • Lighting System Integration Assistance
  • LightLouver Application Design Reviews
  • Troubleshooting

For a complete description of these services view the Design Assistance Services

The information typically required to provide the LightLouver Daylighting System design integration services or to provide a preliminary cost estimate is described on the Customer Enquiry / Assistance Form.  Please provide as much of this information as possible.