Transcript Basic Terms - Lumens

JP Bedell
SDA Lighting
[email protected]
Blog.sdalighting.com
@jamesbedell
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-CANDLES


Light cast on vertical
surfaces such as walls,
faces and hanging
artwork.
Important for visibility,
security and visual acuity.
HORIZONTAL FOOT-CANDLES


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.
[email protected]
Blog.sdalighting.com
@jamesbedell