LIGHTING AND
ACOUSTICS
AP 215
Aditi Padhi
MBS School of Planning and Architecture
LIGHTING CONCEPTS
•
In this unit:
1) Day lighting
2) Integrating day lighting with artificial
lighting
3) Electric light sources and their efficiency
4) Artificial lighting: Lumens; lux; M.F; R.I.R.
lighting level requirement for various
functions
DAY LIGHTING
• Day lighting is the controlled admission
of Natural light – direct sunlight and
diffuse skylight.
DAYLIGHTING
• image
• Place most used rooms
in the daytime on the
south side
• Provide light from two
or more sides of the
room
• Open curtains and
shades in the heating
season
• Light-colored
surfaces reflect light
better (walls and
ceilings)
DAYLIGHTING HISTORY
• Oculus:
Pantheon
Rome, Italy 126
A.D.
• “Natural light is
the only light
that makes
architecture”
Louis Kahn
MAXIMIZE DAYLIGHT
PENETRATION
• Clerestory Windows
• Consider Surface’s
reflectance for Daylight
Penetration
• Day Light Penetration- As
a thumb, daylight
generally penetrates into a
building a distance of 1.5 x
the height of the top of the
windows
BOUNCE DAYLIGHT
• Bounce daylight off
surrounding surfaces
• Bring daylight in
high and wash it down
the space
• MET NY
ADVANCED WINDOW
STRATEGY
• Light colored
pavement or gravel
can reflect
• Wide windowsills can
be used as light
reflectors
• Light shelves are
usually placed above
eye level to prevent
glare from the top
shelf. They also act as
TOPLIGHTING STRATEGY
• When applicable, horizontal openings
(skylights) offer two important
advantages.
• They offer fairly uniform illumination over
very large interior areas.
• Horizontal openings also receive much
more light than vertical openings.
SKYLIGHTS
• Veiling reflections are avoided when
skylights
• A system of baffles can control direct glare
and to some extent veiling reflections.
Assignment
Assignment
Riola Parish Church, Riola Italy Alvar Aalto 1978
Visibility, which is the state of being perceivable
by the eye, is often thought to depend
principally upon the amount of light on the
object or task to be seen, and that more light
on the object or task will make it more
visible. To some degree this is true, but
visibility also depends upon visual acuity (the
ability to distinguish fine details), and
contrast sensitivity (the ability to detect the
presence of luminous, or brightness,
differences). Both visual acuity and contrast
sensitivity vary with task luminance
(brightness), which is determined by the
amount of incident light, where the incident
light comes from, and the reflectivity of the
task.
Daylight in Architecture, Benjamin Evans
TERMINOLOGY
• Illumination:
luminous flux at any point on a surface
exposed to incident light (direct or
indirect)
• Lighting: Method to provide artificial
illumination
• Shading:
produce gradations of light or color
TERMINOLOGY
• Ambient Lighting:
> scattered
> no detectable direction
> backlighting in a room
> can use to give a feel for the main
color in a room
> not dependent on viewpoint
• Diffused Lighting:
> directional
> scatters equally in all directions once hits object
> closest to the color of light
> not dependent on eye position
• Specular light :
> comes from a detectable direction
> bounces off object in preferred direction
> plays a role in shininess
> dependent on viewpoint
TERMINOLOGY
• point source vs spotlight :
> point source: light emitted in all directions
> spotlight: cone-shaped
• positional vs directional
Lighting:
> positional: like a desk lamp
> directional: like the sun
all rays parallel when reach object
MATERIAL
PROPERTIES
1. reflectance of light
a. ambient
> amount of ambient light
> most visible where no direct light hits
b. diffuse
> degree of scattering of light on surface
> matte vs flat paint finish
Color of object == ambient and diffuse
(typically set the same)
Light & Material Properties
Examples
increasing diffuse
increasing ambient
increasing specular
Fluorescent Fixtures
Fluorescent fixtures
are especially
important in places
where the lights are
used extensively,
like kitchens,
playrooms, and
living rooms. CFL’s,
T8 and T5 bulbs are
the most efficient.
Valence Lighting
• image
• Provides efficient
background and
task lighting for the
room
• Total of 70 watts
using T-8
fluorescent bulbs
• Design
recommended
Compact Fluorescent Bulbs
• CF bulbs are 4x as
efficient as
incandescent lights.
Many are equivalent
in size to standard
incandescent bulbs.
This shows a ceiling
light with 2 compact
fluorescent bulbs.
Other Fluorescent Lighting
• Fixtures are
available in a variety
of styles to fit a
home’s décor
• Fluorescent fixtures
should always be
installed in places
that will use lighting
extensively, but they
are not needed in
closets
Carefully Choose Your CF
bulbs
• Energy Star rated CF’s must meet
higher standards and will last longer
• Choose the right size (follow
recommendations)
• Choose the right color (daylight, cool
white, warm white) for your application
(try one and see if you like it)
• Make sure it has a flicker-free,
electronic instant -start ballast
Types of Fluorescent Lights
• Ballast – activates the low pressure gas inside
the bulb by varying the current (used in all
fluorescent bulbs) Always choose electronic
ballasts and instant-start flicker-free bulbs.
• Integral compact fluorescent – single unit
(most common)
• Modular compact fluorescent – separate
ballast and tube
• Ballasts can last 50,000 hours while bulbs
may last 10,000 to 20,000 hours
Energy and Environmental
Savings
• A single 18 watt CF bulb replacing a
standard 75 watt incandescent bulb
saves over its lifetime of 20,000 hours1
• 570 kw-hr of electricity
• 500 lbs of coal
• 1300 lbs of carbon dioxide
• 20 lbs of sulfur dioxide
Task Lighting
• In many cases, it is
more efficient to use
task lighting for
desks, workbenches,
etc. than to
illuminate the entire
room at a high
intensity.
Incandescent Lighting
There are appropriate
places to use
incandescent bulbs,
especially in low use
areas like
• Closets
• Storage rooms
• Utility closets
• Any minimal light
use area
Measure of Lighting Efficiency
• Efficacy - measure of bulb efficiency
ratio of the light output power (visible
region, measured in lumens) to the
electrical input power (measured in
watts).
Standard incandescent bulbs range from
8 to 20, halogen incandescent range
from 12 to 24, while fluorescent bulbs
range from 32 to 104.2
Other Lighting
• Outdoor HID (high intensity discharge)
bulbs include mercury vapor, high-pressure
sodium, and metal halide. The latter two are
more efficient. Mercury vapor have efficacies
of 20-60 compared to a range of 50 to 180
for sodium and metal halide.2 There are also
cold-start CF bulbs for outdoors.
• Indoor halogen lights for high quality or
precise focusing. Better than incandescent
but not as efficient as fluorescent.
• Solar-powered walkway and patio
lights. Easy to install.
Lighting Controls
• Simplest and cheapest strategy – turn
off the lights manually when not in use
• Heat sensors (occupancy)
• Motion sensors (occupancy)
• Light sensors (for outdoors)
• Dimmers
Late Comers Assignment
• 10 Lighting Terminology