Tag Archive: lighting technology and controls

  1. How Do LEDs Work? A Quick Primer on LED Lighting Technology

    Leave a Comment

    One of the most popular acronyms in the lighting design world and around the GPI Design office is “LED”.  So what does it stand for, and how do LEDs work?  While not an exhaustive investigation, this blog post will give you a primer on LED lighting technology and how LEDs work.

    An LED, or Light Emitting Diode, is a semiconductor light source.  When an electrical current flows through the diode, electrons in the current experience an energy drop.  During this drop, energy is released in the form of light.  LEDs emit different colors due to different energy drops or due to a coating on the LED. That’s how GPI can offer different lighting solutions with colors like white, red, blue, yellow, and more.  LEDs are extremely efficient, last longer than traditional light sources, and are capable of producing clearer, crisper light.  LEDs are gradually replacing older forms of lighting, including incadescent bulbs and florescent bulbs, and are quickly becoming the light of the future.

    So how exactly does an LED work?

    1. An LED is hooked up to an energy source.

    2. An electrical current flows from the positive terminal, through the diode, and out the negative terminal.

    3. An electrical current is composed of electrons.  The electrons, when flowing through the diode, drop down to a lower energy state.

    4. During the drop, energy is released in the form of photons, or small packets of light.

    5. The light bounces around in the plastic shell of the LED, and then escapes as visible light.

    An LED gets its energy from a low, constant DC voltage.  An individual LED requires 2-4V of DC power and several hundred mA of current. LEDs connected in series as part of an array require higher voltage.  In order to get the correct DC voltage, LEDs require drivers, which convert incoming AC power to the proper DC voltage and regulate the current.  Thus, a driver is considered the power supply of LEDs.  To control LEDs and achieve affects like dimming or color changing, different controllers are used.

    While it seems like there are many parts to LED systems- drivers, controllers, bulbs, panels, scrims- our Infuse™ Complete LED Backlighting System brings them all together to achieve beautiful backlit features with complete LED backlighting systems.

  2. 7 Reasons Why Flat LED Lighting Panels Are Imperfect Products: Part 2- Solutions

    Leave a Comment

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

    1. Hot spots

    Answer: 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

    Answer: 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

    Answer: 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

    Answer: 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

    Answer: 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

    Answer: Specify a complete LED backlighting system that has power supplies that can run at least 100 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

    Answer: 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 by accessing that dimming capability 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 light panels, enjoy designing your next unique backlit feature!

  3. 7 Reasons Why Flat LED Lighting Panels Are Imperfect Products

    Leave a Comment

    Flat LED panels are new technology, and if you’re a designer or architect you are probably aware of a handful of manufacturers that produce these products.  And while many of the physical characteristics of LED panels are the same across the board, the majority of manufacturers lack the expertise to implement the panels with actual surfaces in actual construction environments. Here are some considerations when specifying flat LED panels for commercial projects:


    1. Hot spots

     

    Edge lit LED panels are manufactured by embedding energy-efficient, high output LEDs along the edges of a thin acrylic panel.  Laser-etched channels distribute light across the face of the panel.  There is often a bright line at the edge of the panel where the actual light source is located.  This bright line can transfer through the surface being backlit, disrupting the visual continuity of the surface.

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

    If engineered incorrectly, too many LED strings will result in bright panels with excessive hot spots at the edges.  Too few LED strings will cause cold spots at the unlit edges and possibly towards the center of the panel.

    3. Cold spots

    If panels are sized incorrectly or LED strings run on the wrong sides of the panel, the light source may not sufficiently transfer across the entire face of the panel, resulting in cold spots towards the center of the panel.

    4. Expensive

    The up-front cost of LED technology is expensive, and it can be difficult for architects and interior designers to convince clients to invest in high-end products.

    5. Imperfections in acrylic batches

    Acrylic production results in slight variations between batches; this is very typical for the acrylic industry, but when you add light to the mix, the imperfections are exaggerated.

    6. Powering every single panel with an adapter

    Not a problem if you’re designing a backlit bartop for a residence, but when designing large commercial features, plugging each individual panel into an outlet is inefficient (and quite ridiculous, if you ask us!).

    7. Varying panel sizes have varying brightness

    Depending on the proportion of the panels (long rectangles or even squares), smaller LED panels will appear brighter than larger panels.  This is due to light bouncing in a decreased area, and also because of the voltage drop that occurs over the longer LED strands.

    One of the elements of being a great designer is knowing the limitations of the product you’re investing in.  Stay tuned for the next blog article which will outline how to design around the above challenges.

  4. Quick Guide to LED Lighting Systems for Sustainable Building Design and LEED credits

    Leave a Comment

    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.