back to the basics:understandingn lighting in the age of led - presented by jp bedell, stan deutsch...
TRANSCRIPT
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 LUMENS DELIVERED 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-
CANDLESHORIZONTAL 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 - 2800K
Halogen Lamp (MR16) = 2900K – 3200K
Fluorescent Lamps = 2700K – 6000K
Ceramic Metal Halide = 4200K (Typical)
2700K 3500K
CRI is short for Color Rendering Index
This is a relative scale from 0-100 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 80-90+ 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 10th 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 = 10 - 20FC
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.
