JP Bedell SDA Lighting

Understanding Lighting in the Age of LED

 Review Basic Terms Describing Light Source  Points of Reference – Comparing LED to Traditional Light Sources  How to Read a Cut Sheet  Evaluating a Sample  Writing a Specification

 What is a Lumen?  It is the measure of the total visible light emitted by a source.  How much light a source creates or delivers.

SOURCE LUMENSDELIVERED LUMENS

 The amount of a light one candle casts one foot away.  Think of this as the amount of light cast in a direction at a target area. Not emanating from the source.

VERTICAL FOOT-CANDLES HORIZONTAL FOOT-CANDLES  Light cast on vertical surfaces such as walls, faces and hanging artwork.  Important for visibility, security and visual acuity.  Light cast on horizontal surfaces like desks, countertops, and the ground.  Important for task lighting, path of egress and basic visibility.

 This is the “tone” of white light a source creates.  Think of the difference in white light from a bright sunny day and a warmly lite restaurant.  Expressed in degrees kelvin  Typically ranging from 2700K – 6000K

 Incandescent Light Bulb = 2700K K  Halogen Lamp (MR16) = 2900K – 3200K  Fluorescent Lamps = 2700K – 6000K  Ceramic Metal Halide = 4200K (Typical)

2700K3500K

 CRI is short for Color Rendering Index  This is a relative scale from rating how well light sources reflect colors back to our eyes.  Commercial light sources range from 70 CRI (metal halide) To 100 CRI (High Quality Halogen)  LED sources are typically CRI

 0-10V  Electronic Low Voltage Dimming (Trailing Edge)  Triac

Work With Your Electrical Contractor

Comparing LED to Traditional Light Sources

 We use foot-candle targets as a guideline for providing enough light for certain tasks and spaces.  The 10 th Edition of the IES Handbook has broken light level recommendations down by age.

 Simple Orientation in space = 5-10FC  Classrooms = 50 – 100FC  Lobby of Office Building = FC  Reading = 20 – 50FC  Gymnasium = 20 – 50FC  Museum = 50 – 100FC

 When evaluating traditional light sources wattage used to be the point of reference. Today it must be lumens.  A 60W Incandescent Light Bulb generates 800 Lumens. Today a 9.5 watt bulb can do the same thing.

 Fixture Dimensions  Mounting  Brightness  Color Temperature and CRI  Beam Spread and Optical Accessories (if applicable)  Wattage  Dimming Compatibility

 Brightness  Color Quality  Basic Construction

 Manufacturer + Part Number  Mounting  Complete Description  Required Voltage  Contractor Notes  Customizations

Recess mounted LED adjustable accent light with 4-1/2" square aperture. Fixture provided with LED light engine capable of dimming from 3000K to 2200K in 90+CRI. Fixture provided with 0-10V dimming driver standard. Fixture provided with trim plate complete with white regress and flange. Fixture provided with New Construction housing measuring 22-1/8"L X 13"W X 7"T. Fixture input voltage is 120V. Total input wattage to fixture shall be 32 watts. Contractor to confirm channel bar requirements and and review housing size for construction feasibility. Electrical contractor to provide compatible dimmers.