Posts Tagged ‘green lighting’

LED Wall Packs – Prismatic Lenses v. Clear Glass Lenses

Friday, June 4th, 2010

As LED wall packs gain market share the most common designs for wall packs will most likely change.   LED wall packs do not effectively use prismatic lenses like more traditional light sources.  The optics of the fixture do not work the same way.  Consequently, LED wall packs are more likely to be designed to use clear or frosted non-prismatic lenses.

Up to now the most popular commercial wall packs were the type that had prismatic lenses made of either polycarbonate or heavy borosilicate glass.  The wall packs most often use metal halide, high pressure sodium, or compact fluorescent lamps and ballasts.  The prismatic lens, when properly formed and used provides a refractor type effect that diffuses and distributes the light with minimal light loss.  The net effect is the light can be directed down or out, and the prismatic lens reduces glare, makes looking at the light less blinding, and effectively distributes the light.

Medium LED Wall Pack

Medium Wall Pack with Prismatic Borosilicate Glass by Access Fixtures

LED wall packs are more likely to be designed to use clear or frosted non-prismatic lenses.  When LEDs are used in wall packs with borosilicate glass, the optics of the fixture do not work the same way.  For the LEDs to be effective they have to hit the glass at different angels.  In most instances this impedes the performance of the LEDs and the total light output.  Efficacy can be lowered by modifying the placement of the LEDs to regain quality optics.

LED Wall Pack Full Cutoff

LED Wall Pack Full Cutoff

LED Wall Pack with Full Cut Off Optics – Series C Wall Pack by Access Fixtures

The Series C Wall Pack uses Xicato LED Modules and Advance Xitanium Drivers.

The primary reason for the photometric change is the difference in the light source.  Metal halide, high pressure sodium, and compact fluorescent lamps blast light in all directions.  LEDs are a point source.  This is similar to the why a halogen filament can be directed in a PAR38, and fluorescent coils in the same lamp shell blow light everywhere.

While LED wall packs will still be made and sold with prismatic lenses because there will be traditionalists that want prismatic lenses, LED wall packs with clear and frosted lenses should be considered first.  To do so, it must be considered what is being lit and/or where the light is to be directed.  A full cut off luminaire such as the wall pack shown above effectively lights the area below it and will not be blinding to people as they approach where it is mounted.  The Series C Wall Pack is also Dark Sky compliant as it has full cut off optics.

If the light is to be directed out or at something an adjustable LED wall pack is a superior choice.  Featuring clear glass the LED point source can beam spread can be controlled and the light can be directed where it is desired. When lighting objects or areas though, it must be considered if the LED light source will shine in peoples’ eyes.  The LEDs can be very intense when directly viewed.

Adjustable LED Wall Pack

Adjustable LED Wall Pack by Access Fixtures

This wall pack can be wall mounted or pole mounted.

Visit Access Fixtures at http://www.AccessFixtures.com .  With 30 years of collective experience, Access Fixtures offers standard and custom lighting fixtures that are long lasting and energy saving.  At AccessFixtures.com you can easily specify exactly what you need, and then with a click place your order online. With custom manufacturing capabilities, Access Fixtures can build lighting fixtures to the performance specifications you require and does so at a very competitive price.

Access Fixtures extensive line up of interior and exterior lighting fixtures includes lighting fixtures for sports, commercial, industrial, residential and hospitality applications.  Fixture types include wall packs, area lights, bollards, garage lighters, vandal resistant, exit and emergency, high bay, low bay, linear fluorescent, track lighting, chandeliers, and grow light fixtures.  Lamp/Ballast types include LED, induction, magnetic ballast and electronic pulse start metal halide (eHID), T5 and T5HO linear fluorescent, T8 linear fluorescent, plug in compact fluorescent, and high pressure sodium.  Contact Access Fixtures to discuss the correct long lasting, energy saving solution that best serves your needs.

LED Lighting – The Future of LED Luminaires will be Forward Retrofittable

Thursday, May 27th, 2010

Up to now virtually all LED luminaires were made with LEDs mounted directly into a heat sink.  They were typically wired in line and went back to a driver.  This caused multiple performance issues.  3 companies have developed LED modules that are replaceable, enabling LED luminaires to be repairable as well as forward retrofittable.  That changes everything.

The issue with past LED fixture construction was the LEDs were usually permanently installed, or if not permanently installed, at least installed into pre-drilled holes specific to the LED package being used.  The LED was then wired in series back to a driver.  If an LED failed, it was virtually impossible to fix the fixture.  Also, upgrading the LEDs was impossible.  There was not an effective was to change out all the LEDs.

That has changed with the advent of LED modules.  LED modules are LEDs that are fitted into a package that enables them to be quickly taken out of a luminaire.  If a LED module fails, it can be changed just like a light bulb.  If technology advances, and it will, the LED modules can be swapped for the more energy efficient LEDs or higher lumen LEDs.  Also, with some LED modules, even the optics can be changed.

Three companies are leading the charge with LED modules.

Xicato products come in multiple wattages, have changeable optics, and are available in luminaires now.  Xicato LED modules are available in luminaires from Access Fixtures.

Xicato LED module chip

Xicato LED Module

GE is introducing a product this year.  Current press releases list it as being available in a track light system.  So far it is listed for indoor applications only and has limited light output.  Click here to view the press release.

GE LED Module

GE LED Module

Bridgelux is the third company with an announced LED module.  The Bridgelux Helieon LED module  has won awards, but currently does not seem to be commercially available.  At the time of this blog, it does not appear to be available in a luminaire.

Helion LED Module

Helieon LED Module by Bridgelux

LED Wallpack with Xicato LED Modules

Adjustable LED Wall Pack with Xicato LED Modules Shown From Side & Bottom

Series C Wallpack with Xicato LED Modules

Xicato LED Modules in a Series C LED Wall Pack with Full Cut Off Optics

Area Lighting Luminaire with Xicato LED Modules

Xicato LED Modules shown with optics in an Area Lighting Luminaire for street lighting or lighting parking lots.  This luminaire is by Access Fixtures.

Visit Access Fixtures at http://www.AccessFixtures.com .  With 30 years of collective experience, Access Fixtures offers standard and custom lighting fixtures that are long lasting and energy saving.  At AccessFixtures.com you can easily specify exactly what you need, and then with a click place your order online. With custom manufacturing capabilities, Access Fixtures can build lighting fixtures to the performance specifications you require and does so at a very competitive price.

Access Fixtures extensive line up of interior and exterior lighting fixtures includes lighting fixtures for sports, commercial, industrial, residential and hospitality applications.  Fixture types include wall packs, area lights, bollards, garage lighters, vandal resistant, exit and emergency, high bay, low bay, linear fluorescent, track lighting, chandeliers, and grow light fixtures.  Lamp/Ballast types include LED, induction, magnetic ballast and electronic pulse start metal halide (eHID), T5 and T5HO linear fluorescent, T8 linear fluorescent, plug in compact fluorescent, and high pressure sodium.  Contact Access Fixtures to discuss the correct long lasting, energy saving solution that best serves your needs.