GPI International Blog: Beneath the Surface

A sampling of the backlit onyx slabs we displayed at Neocon in Chicago this past June- if only we had a dime for every time we heard "is that real stone?". 100% natural!

The last post on "Beneath the Surface" discussed some of the challenges that flat LED panels pose when used for backlighting applications.  This post address each point with a design-driven solution. Anything we're missing?  Leave a comment and we will address it with another blog post!

1. Hot spots

Depending on the translucency of the surface being backlit, hot spots along the edges of LED panels are often a major design concern.  You can accommodate this setback by burying the hot spot in structural framing, or increasing the space between the backlit surface and the LED panel to diffuse the hot spot.

2. Difficult to determine how many edges to run LEDs across

This is a tough one- since most LED panels are custom produced to size, it just takes experience and experimentation to know how many edges require light sources.

3. Cold spots

Consider the ideal size of the panels; although many manufacturers can produce flat LED panels in 4’ x 8’ sheets, it can be beneficial to break that module down into smaller panels.  A good rule of thumb is to allow each LED string to throw light 15” – 20” across the face of the panel.  So, if your panel is over 20” wide, consider running strings on two parallel sides. 

4. Expensive

LED panels have higher upfront costs, but can have dramatic energy savings, especially when the LED lighting system is controllable.  By using flat LED panels in applications for which they are best suited (feature areas which require evenly illuminated surfaces and when you have limited space in which to throw light), you can preserve your client’s budget and make the most impact where needed.

5. Imperfections in acrylic batches

Tight quality control standards will ease this challenge.  Unfortunately, designers don’t have much control over this part of the production process, so be sure to choose a manufacturer that you trust and that has strong attention to detail.

6. Powering every single panel with an adapter

Specify a complete LED backlighting system that has power supplies that can run at least 50 linear feet of LED strings.  Running an entire backlit wall or ceiling back to a central power source results in more efficient wiring and installation.

7. Panels have varying brightness

Balance out the brightness among panels by specifying dimming packs that can control each LED string and each panel individually.  If a small panel appears brighter, or a panel closer to natural sunlight appears dimmer, you can control the brightness of the panels via a manual user interface or through a central building management system.

Have you experienced any of the above issues?  How did you design around those product limitations?  Now that you know a bit more about flat LED panels, enjoy designing your next unique backlit feature!

Project Update: LED Panels Wired and Installed, Glass is Evenly Backlit

Backlit Glass Columns by GPI | AED Idea Center | Washington, D.C.

Architect: Studio 27 Architecture

Lighting Designer: MCLA

Application: Backlit frosted glass at eight columns

Products: Frosted glass panels, GPI LED Panels at 3500 K, GPI Custom Dimming Packs that communicate with Lutron 5000 Graphic Eye

Integration: Diffuser films to hide lamp image and disguise hot spots, GPI Dimming Packs to balance brightness between large and small panels

Above image indicates construction progress from the field.  Check back for completed photographs when the dimming interface and surrounding finishes are complete!

Acronyms galore.  The letters "L", "E", and "D" on my keyboard are going to be worn out after this blog post!

Lighting systems typically constitute the highest energy use in commercial buildings. The USGBC (United States Green Building Council) has recognized the energy savings potential in general lighting systems, and LED lighting systems can be a significant contributor to obtaining Leadership in Energy and Environmental Design (LEED) certification for a new building. LED lighting systems can contribute to LEED certification in at least three areas: Energy and Atmosphere, Indoor Environmental Quality, and Innovation and Design Process.

Energy and Atmosphere (EA) 35 possible points

Prerequisite 1: Fundamental Conditioning of Building Energy Systems

Prerequisite 2: Minimum Energy Performance

Credit 1: Optimization of Energy Performance (worth 1 to 19 points) is the primary area where LED lighting can have an impact. The proposed building design must demonstrate improved performance as compared to baseline criteria.   The greater the performance from baseline, the more points are awarded.

-Reduced carbon emissions (as compared to incandescent lighting)
-Low operating temperatures reduce heat dissipation into spaces, cutting the strain on the HVAC system and ultimately saving air conditioning costs
-Compatibility with photovoltaics
-Minimize energy usage by integrating LED lighting systems into Lutron or other building management system

Indoor Environmental Quality (IEQ)

Credit 6.1: Controllability of Systems- Lighting
Control of the lighting system by individual occupants or specific groups in multi-occupant spaces can potentially earn 1 point toward LEED certification. LED luminaires provide the opportunity to work as part of a lighting control plan/central building management system. They provide light instantaneously once power is applied, requiring no warm up time. LED lighting systems can also be dimmed to provide variable light output depending upon the needs of the occupant. The efficacy of LEDs efficacy actually increases when they are dimmed due to lower junction temperatures. Continuous, non-stepped dimming provides occupant comfort and increases efficiency.

Innovation and Design Process (ID) worth from 1 to 5 points

Credit 1: The utilization of innovative products and processes may earn between 1 and 4 points toward LEED certification. As LED lighting systems for general lighting represent new, innovative technology, they may qualify for LEED certification credit. LEED does not award this credit if a product is already obtaining points in another category, so design teams must choose where the most impact can be made and pursue credit(s) accordingly.

Other benefits of LED lighting:  
LED (light emitting diode) lighting systems are not only environmentally sustainable, but can be cost efficient as well. Even if your building isn’t striving for LEED certification, there are numerous benefits that are attractive to designers and building owners. While the upfront costs of LED lighting systems and dimming capability are often greater than traditional lighting methods, the life cycle and can even add value to the property in the long run. 

-Fewer building materials required
-Reduced operational costs for electricity and maintenance
-No hazardous materials or wastes (lead and mercury free)
-Longer lifespan= less waste for landfills
-Simpler installation
-Possible commercial building tax deductions 

More information on GPI's FLAT-Lite™ LED lighting system complete with commercial capacity power supplies and dimming options.

The above summary is based on LEED v3 which was released by the USGBC in April 2009 for LEED New Construction and Major Renovations (NC).  This summary does not include the potential of LED lighting to earn points for exterior applications and light pollution reduction.