BUILDING UTILITIES
ACOUSTICS AND LIGHTING / ILLUMINATION
INTRODUCTION TO ACOUSTICS and LIGHTING
1.
2.
The psycho-physics of acoustics and lighting
Acoustical treatment and corrections
The hearing mechanism of the ear senses sound waves, converts them to information, relays
it to the brain, brain interprets the information as sound.
ACOUSTICS: branch of physics concerned with sound.
1. SOUND SOURCE – generation of sound
2. TRANSMISSION PATH – airborne, structure borne, waterborne
3. RECEIVER (RECEIPIENT) – accepts the sound whether wanted or unwanted
What is the difference between sound and noise?
Sound is what we hear.
1. WANTED SOUND – Speech, Music
2. UNWANTED SOUND – Noise (objectionable or not desired)
ARCHITECTURAL ACOUSTICS
Effect of building design on sound control in buildings
Principles of acoustics to create a satisfactory acoustical environment
SOUND WAVE
Longitudinal pressure wave in air or an elastic medium especially one
producing an audible sensation
1. Sound Wave
2. Increased Volume Sound Wave
3. Increased Frequency Sound Wave
PITCH and FREQUENCY
 Frequency is the number of times per second that a vibrating body
completes one cycle of motion
 Unit for frequency is hertz (Hz = 1 cycle per second)
 Low pitched or bass sounds have low frequencies
 High-pitched or treble sounds have high frequencies
 Normal person can hear frequencies from roughly 20 to 20,000 Hz
 Human speech is mainly in the range 300 to 3,000 Hz
SOUND INTENSITY – Rate of sound energy transmitted in a specified direction per
unit area normal to the direction
DECIBEL (dB) - a logarithmic scale applicable to any parameter.
Types of Sound Control for Architectural Acoustics
1. Acoustical environment in a room: positioning sound sources to the
listeners, and arranging appropriate absorptivity or reflectivity levels for all
interior surfaces
2. Isolation of unwanted sounds: insulating building occupants from
intrusive noise
Three Aspects of Acoustical Design of Buildings
1. Planning to keep noise sources as far as possible from quiet areas
2. Internal acoustics of rooms
3. Structural precautions to reduce noise penetration
Three Degrees of Acoustic Treatment
1. Site (landscape as sound barrier)
2. Architectural Elements (building materials, furniture, furnishings)
3. Acoustic Materials (specifically rooms needing special acoustic treatments)
(e.g. Conference Room, CEO Office, etc.)
Page 1 of 10
BUILDING UTILITIES
ACOUSTICS AND LIGHTING / ILLUMINATION
How Is Vibration Isolated and Controlled?
To reduce the problem to a single mass supported
by a spring and a damper
SOUND DAMPENER
Damping – dissipates vibrational energy before it can
build up and radiate as sound.
SOUND ISOLATION (Spring)
Noise isolation uses physical barriers to block out sound. Noise
isolating refers to the physical process of isolating your ears from
outside sound waves
REVERBERATION
(Reverberation is Good for Music, Bad for Speech)
Prolongation of the sound in the room caused
by continued multiple reflections
SOUND PRESSURE LEVEL (Lp)
Sound pressure converted to the decibel scale
SOUND PRESSURE
The amount of air pressure fluctuation a noise source creates
We "hear" or perceive sound pressure as loudness.
Sound pressure is usually expressed in units called PASCALS (Pa)
Difference between an Echo and Reverberation
An ECHO can only be heard by humans when the distance between the
source of the sound and the reflecting body is more than 50 feet in distance.
A REVERBERATION can occur when a sound wave is reflected off a nearby
surface.
SOUND POWER
The sound energy transferred per second from the noise source to the air
Power is expressed in units called watts (W)
Like sound pressure, sound power (in W) is usually expressed as sound
power levels in dB.
SOUND POWER LEVEL
Sound power level, Lw, the total sound energy radiated per second.
LOUDNESS
The human impression of the strength of a sound
Page 2 of 10
BUILDING UTILITIES
ACOUSTICS AND LIGHTING / ILLUMINATION
REFLECTION and ABSORPTION
REFLECTION, DIFFUSION, AND DIFFRACTION
REFLECTION
The repetition of a sound resulting from reflection of the sound waves
1.4-meter height of speaker = average height of a person
Smooth surfaces can reflect sound waves
CONCAVE REFLECTOR (focusing)
Concave sound-reflecting surfaces (barrel-vaulted ceilings in churches and curved
rear walls in auditoriums) focus sound, causing hot spots and echoes in the
audience seating area
Sound is concentrated on an area
FLAT REFLECTOR
Flat, hard-surfaced building elements (large enough and oriented properly)
effectively distribute reflected sound. The reflector is tilted slightly to project sound
energy toward the rear of an auditorium.
FLAT CEILING Good for Speech halls
Hard, sound-reflecting flat ceiling provides useful sound reflections covering the
entire seating area in a lecture room
SLOPED CEILING Good for Music halls
For concert halls: long reverberation, high ceilings, sound-reflecting walls are
preferred; ceilings that are diffusing can improve audibility of lateral sound by
diminishing the strength of ceiling reflections
ECHOES
With magnitude and delay. The distinct repetition of the original sound and is
sufficiently loud to be clearly heard above the general reverberation and background
noise in a space.
FLUTTER ECHO
Repetitive inter-reflection of sound energy between opposing parallel or concave
sound-reflecting surfaces heard as a high-frequency ringing or buzzing
To prevent flutter echo, avoid parallel surfaces, provide deep sound-absorbing
treatment, or break up smooth surfaces with splayed or ‘scalloped” elements.
Elevator situation – control all floor, ceiling, and parallel walls to avoid flutter echo
FOCUSED REFLECTIONS
 ELLIPSE – 2 focus points, sound projected in any direction from
point will travel to another (e.g. basketball arena – sound disperses at sides)

PARABOLA – All rays from the focus of a parabola to its surface
will be directed outward as parallel rays
focus on one side / centroid – most sound at center

CREEP – Dome-like rotundas (Rotunda Effect) exhibit this guided reflection
phenomena – Indirect echo; Longitudinal Wave

ANTI-FOCUSING – CONVEX Surfaces, undesirable focusing effect may be partially
overcome
by covering the curved surface
CONVEX REFLECTOR (anti-focusing)
Large convex, hard-surfaced building elements are the most effective sounddistributing forms.
The reflected sound energy from convex surfaces diverges, enhances diffusion,
desirable for music.
Reflected sound from convex surfaces is more evenly distributed across a wide
range of frequencies.
Page 3 of 10
BUILDING UTILITIES
ACOUSTICS AND LIGHTING / ILLUMINATION
DIFFUSION
(E.g. Theatres and cinemas – equally distributed sound)
Scattering or random redistribution of a sound wave from a surface; occurs when the
surface depths of hard-surfaced materials are comparable to the wavelengths of the
sound.
DIFFRACTION
when a wave encounters an obstacle or opening
e.g. Material Solution – Perforated Acoustic Tile
Bending or “flowing” of a sound wave around an object or through an opening
ABBREVIATIONS:
NOISE REDUCTION COEFFICIENT (NRC)
A single-number index for rating how absorptive a particular material is.
What Is The Difference Between Insulation & Absorption?
SOUND INSULATION
Is required in order to eliminate the sound path from a source to a receiver
such as between apartments in a building, or to reduce unwanted external
noise inside a concert hall.
e.g. Mineral Wool – Insulation Material
Bricks – both thermal and acoustic-insulation
Bahay Na Bato – thermal storage; thick stone wall
Sound is kept for a period of time – considered INSULATIVE
SOUND ABSORPTION
Occurs when some or all of the incident sound energy is either converted
into heat or passes through the absorber.
e.g. Concrete – Absorb
SOUND TRANSMISSION LOSS (TL);
A door’s ability to reduce noise is called its sound transmission loss (TL)
effectiveness.
TL is a value given in decibels, which is determined by measuring sound pressure
levels at a certain frequency in the source and receiving rooms.
SOUND ABSORPTION COEFFICIENT (SAC)
The fraction of the randomly incident sound power which is absorbed, or otherwise
not reflected.
SOUND TRANSMISSION CLASS (STC)
Is a single-number rating of a material’s or assembly’s barrier effect.
STC 25 – Normal speech heard easily from room to room
STC 30 – Empty wall, loud speech can be heard easily
STC 35 – Loud speech can be heard but not understood
STC 51 – Loud speech can’t be heard
STC 53 – For a Conference Room, Interrogation Room; loud speech can’t be heard
Higher number of STC means more absorptive
Page 4 of 10
BUILDING UTILITIES
ACOUSTICS AND LIGHTING / ILLUMINATION
INTRODUCTION TO LIGHTING (ILLUMINATION) TERMINOLOGIES
LIGHTING (ILLUMINATION): deliberate use of light to achieve practical or aesthetic effects
Lighting includes
1. Light Sources (lamps, light fixtures)
2. Natural Lighting/Illumination – daylight (windows, skylights, light shelves)
Daylighting - main source of light during daytime
Proper Lighting
1. Enhance task performance
2. Improve the appearance of an area
3. Positive psychological effects on occupants
LIGHTING TERMINOLOGY
Candlepower (CP): unit of luminous intensity of a light source
Candela (cd) in SI units: index of the ability of a light source to produce illumination
A candle has a luminous intensity in the horizontal direction of approximately 1
candlepower (candela), Candela and the candlepower have the same magnitude.
Lumen (lm)
 Quantitative unit for measuring the flow of light energy (referred in the lighting
field as luminous flux) emanating from 1 ft2 of a 1 ft2 surface of 1
candlepower/light output
 English system of units - 1 lumen is equal to the luminous flux emanating from 1
ft2 of a hypothetical surface all points of which are 1 foot from a uniform point
source of 1 candlepower
LIGHTS
 Rays that travel in a straight line until they encounter some object
 Rays are absorbed, reflected, or transmitted
 The proportion of light absorbed, transmitted, or reflected depends upon the type
of material and the angle of incidence of the light rays as measured from the
perpendicular to the surface
ABSORPTANCE
The ratio of light absorbed by a material to the incident light falling on it
All materials absorb some light; darker objects absorb more than lightercolored objects.
REFLECTANCE, REFLECTION FACTOR, OR REFLECTANCE COEFFICIENT:
Ratio of light reflected by a surface to the incident light falling on it
Reflection of light is either specular, diffuse, or some combination of the
two.
SPECULAR REFLECTION
 “Regular reflection” (kind of reflection observed in a mirror) angle of
reflection is equal to the angle of incident light
 Polished or shiny surfaces reflect light when the incident ray is directed
to the surface at an angle
DIFFUSE REFLECTION
 The reflected light is scattered in all directions so that the reflecting
surface appears equally bright from any angle of view. Any surface with
a sandpaper texture reflects light diffusely
 SI units - 1 lumen is the luminous flux emanating from 1 m2 of a surface all points
of which are 1 m from the 1-candela source.
ILLUMINATION - the density of luminous flux, expressed as lumens per unit area.
FOOTCANDLE (FC): One lumen of luminous flux spread uniformly over an area of 1
ft2 produces an illumination of 1 footcandle
SI lumen spread over 1 m2, the illumination is expressed in lux (lx).
footcandles =
lux =
lumens / ft2
lumens / m2
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BUILDING UTILITIES
ACOUSTICS AND LIGHTING / ILLUMINATION
TRANSMITTANCE, LUMINOUS TRANSMITTANCE, TRANSMISSION FACTOR,
OR COEFFICIENT OF TRANSMISSION
 Ratio of light transmitted through
 A material to the total incident light falling on it
 Light transmission may be either direct, diffuse, or a combination of the two
GLARE
Effect of excessive brightness in the field of view, causing annoyance or
discomfort and interfering with vision; may be direct from a light source, or
reflected from a shiny surface
DISCOMFORT GLARE – From Natural Light
DISABILITY GLARE – From Artificial Light
DIRECT TRANSMISSION – Light passes through clear, transparent materials
DIFFUSE TRANSMISSION
Light is scattered evenly in all directions, appearing equally bright from any
angle of view. Materials that transmit light in a diffuse pattern are known as
translucent materials.
REFRACTION: bending of a ray of light as it passes obliquely through a material
WORK STATION
The immediate contiguous area in which a worker performs visual tasks (desk,
desk return, table that function as one task location, conference table shared by
several workers)
WORK PLANE – The surface on which the visual task is performed and at which the
illumination is specified and measured.
PRIMARY SOURCE – A luminous source where light energy is generated and
transmitted directly to a task
SECONDARY SOURCE
Surfaces that derive their brightness from reflected incident illumination
The sun is the ultimate primary source, the moon is a secondary source of light.
LAMP: A generic term for artificial light source
Bulbs: Incandescent filament lamps
Tubes: fluorescent lamps
Lamps: H.I.D. light sources
FOOTLAMBERT (FL): A quantitative unit for measuring brightness
Brightness (luminance): an index of the intensity of light being emitted, transmitted
or reflected from a surface
Brightness is the perceived light
Luminance is a measured quantity
FOOTCANDLE: the illumination is on a surface
FOOTLAMBERT: the brightness is from a surface
LUMINAIRE – A complete lighting unit consisting of a lamp or lamps, together with
parts designed to distribute the light, to position and protect the lamp(s), and to
connect the lamp(s) to a power supply; referred to as a “fixture.”
REFLECTOR – Device for redirecting the radiant energy of a lamp by reflecting it in a
desired direction
REFRACTOR
(e.g. Track Light)
Device for redirecting the radiant energy of a lamp in the desired direction by
refraction through a lens
EFFICIENCY – The ratio of light output (luminous flux) to the light produced by lamp
EFFICACY
light covered per square area
The ratio of output of luminous flux, expressed in lumens, to the power input
in watts, expressed in “lumens per watt.”
Page 6 of 10
BUILDING UTILITIES
ACOUSTICS AND LIGHTING / ILLUMINATION
THREE TYPES OF LIGHTING
1. GENERAL
Provides an area with overall illumination; provides fairly uniform lighting
Example: ceiling fixtures that light up large areas.
2. TASK (LOCAL)
Increases light levels over the work and immediate surroundings. Local
lighting often allows the user to adjust and control lighting and provides
flexibility for each user.
LOCALIZED-general lighting uses overhead fixtures
in addition to ceiling fixtures to increase
lighting levels for particular tasks.
3. ACCENT
Directional lighting to emphasize a particular object or draw attention to a
display item.
DIFFERENT TYPES OF LIGHT FIXTURES
1. DIRECT - Direct lighting tends to create shadows.
2. DIRECT-INDIRECT - distribute light equally upward and downward
3. INDIRECT - distribute 90 to 100 percent of the light upward
4. SHIELDED (VARIOUS TYPES)
Diffusers, lenses and louvers to cover bulbs from direct view to
prevent glare and distribute light
DIFFUSERS
Translucent or semi-transparent (see-through) covers
made of glass or plastic; bottom or sides of light fixtures to
control brightness
A good lighting plan combines all three types to light an area, according to
function and style.
NATURAL LIGHTING
A lighting source that closely replicates natural sunlight can be considered
natural light source.
DAYLIGHTING
 The most practical method of passive solar energy utilization in commercial buildings.
 Reduces lighting energy use and cooling load as well.
LENSES
Clear, transparent glass, plastic covers; incorporates
prisms and flutes to distribute light in specific ways
LOUVERS
Baffles that shield the bulb from view and reflect light;
can be contoured to control light and decrease brightness.
Parabolic louvers are specially shaped grids that
concentrate and distribute light.
 Sunlight is a highly efficient source of illumination
(Produce levels of illumination 50 times as high as those
recommended for artificial illumination)
Page 7 of 10
BUILDING UTILITIES
ACOUSTICS AND LIGHTING / ILLUMINATION
LIGHTING SYSTEM TYPES
Lighting systems are conventionally divided into FIVE CATEGORIES
according to how they control or distribute light: They differ principally in the
proportion of light directed upward or downward.
1. INDIRECT
2. SEMI-INDIRECT
3. GENERAL-DIFFUSE and DIRECT-INDIRECT
4. SEMI-DIRECT
5. DIRECT
Distribution of Light Emitted by Luminaire
Type
Upward (%)
Downward (%)
INDIRECT
90 – 100
0 – 10
SEMI-INDIRECT
60 – 90
10 – 40
GENERAL DIFFUSE
40 – 60
40 – 60
SEMI-DIRECT
10 – 40
60 – 90
DIRECT
0 – 10
90 – 100
INDIRECT
Walls and ceiling must have a high-reflectance finish
Room illumination is diffuse, shadowless, uniform, and with low glare
Inefficient, since all of the useful light reaches the working plane only after a double
reflection – within the fixture and off the ceiling
SEMI-INDIRECT
 More efficient than indirect
 Allow higher levels of illumination without glare
 Employs a translucent diffusing element through which the downward
component shines
 Ceiling is the principal radiating source, and the character of the room lighting
is still diffuse
GENERAL-DIFFUSE AND DIRECT-INDIRECT
 Fixtures distribute approximately an equal amount of light upward and downward
 Provide a bright ceiling and upper wall background for the luminaire
 General-diffuse fixtures (diffusing globe) emit light equally in all directions
 Direct-indirect fixtures have an open top, luminous side, and diffusing bottom
 Their light output has very little horizontal component
SEMI-DIRECT
 The minor upward component serves to illuminate the ceiling
 Shadowing in the space not a problem upward component is
at least 25 percent and the ceiling reflectance is at least 70 percent
DIRECT
 Inherently efficient; basically all light is directed downward
 Illumination of the ceiling is entirely due to light reflected from the floor and room
furnishings
 Require a light, diffuse, high-reflectance floor, unless a dark ceiling is desired for
aesthetic purposes
 Since illumination is largely independent of wall reflectance, walls may be any
color.
TYPES OF LIGHTS or LAMPS
ELECTRICALLY POWERED LAMPS
1. INCANDESCENCE
a. Incandescent Lamps
b. Halogen Lamps
2. LUMINESCENCE
a. Electron-Stimulated Luminescence (ESL)
Compact Fluorescent Lamp (CFL)
b. Discharge
Fluorescent Tube
High Intensity Discharge (HID) – Low Pressure Sodium (LPS),
High Pressure Sodium (HPS), Metal Halide (MH)
c. Solid-State Lighting
Light Emitting Diode (LED)
Page 8 of 10
BUILDING UTILITIES
ACOUSTICS AND LIGHTING / ILLUMINATION
LIGHT SOURCE TYPES
TWO MOST COMMON TYPES
(INCANDESCENT & FLOURESCENT)
A.) INCANDESCENT
 The least efficient of all lamps (efficacies of less than 20 lumens per watt)
 Efficiency increases with rated wattage (15 percent for a 10-watt lamp; 25 percent for
a 1500-watt lamp)
 Color (white with a large yellow-red component); exact color depends on temperature
as determined by wattage; High-wattage lamps are blue; low-wattage lamps are
yellow; Dimmed lamps of a given wattage give off a yellow-red light.
 Reflector lamps are a specially designed type of incandescent lamp
 SPOTLIGHTS - narrow-beam designs
 FLOODLIGHTS - wide beam designs; soft floodlights glass (indoor),
hard glass (outdoor)
 Fixtures for these lamps act as a lamp holder, since beam control is built into the lamp
B.) FLUORESCENT
 More efficient than incandescent lamps (20 times longer life)
 More light is emitted by a 40-watt fluorescent tube than by a 100-watt incandescent
bulb.
 Efficacy depends on their color-rendering capabilities
 Most efficient - warm white, cool white, and white (best for industrial, institutional,
general office); economical light production
 Deluxe warm white, deluxe cool white, and other “deluxe” types used where color
rendition is important and lower efficacies are acceptable.
 Fluorescent light output dependent on the operating temperature of the tube, which is
affected by the ambient temperature
 Shape – tubular, straight tubes
 Standard 4-foot (1.2 m) tube - rated at 40 watts
 General Electric’s circular fluorescent lamp called the Circlite, fits into an ordinary
incandescent socket
WARM WHITE
Refers to a color temperature around 3000K, providing a yellowish-white light.
HIGH-INTENSITY DISCHARGE (H.I.D.)
Include mercury vapor, metal-halide, and high- and low-pressure sodium lamps
High efficacy and, with appropriate color correction
Utilized in almost any application, indoor or outdoor, that does not have critical color criteria
MERCURY VAPOR (M-V) LAMPS
(e.g. Street Lamps)
 Distinctive blue-green light
 Lamps available in clear, white, color-corrected, and white-deluxe
 Efficacies higher than incandescent but lower than fluorescent lamps
 Lamp life is extremely long (since the long life is predicated on their being left on for
long periods of time, they are not suitable for applications that are subject to frequent
switching)
 Applicable to indoor and outdoor use, if proper attention is paid to color and fixture
brightness. High mounting necessary to avoid glare and to permit adequate area
coverage
 Used in industrial spaces and stores
METAL-HALIDE LAMP
(e.g. Billboards)
 Basically a mercury lamp with halides of metals, such as thallium, indium, or sodium,
added. The addition of these salts causes light to be radiated at frequencies other than
the basic mercury colors and increases efficacy
 Color is much warmer than that of the mercury light
HIGH PRESSURE SODIUM (HPS) LAMP
 Light is a yellow-tinted color due to the sodium contained within them under high
pressure. Complementary white sources used in conjunction can make the color of this
light even more acceptable
LOW-PRESSURE SODIUM LAMP
 The most efficient source available, but inappropriate for general lighting because of its
distinctive deep yellow light output
 Very high efficacy
 Widely used for highway lighting, where the discernment of objects is the primary
objective
 Use for building’s exterior applications, inside warehouses, or as after-hours security
lighting
COOL WHITE
Denote a color temperature of around 4100 K. The Cool White (CW) designation is
used specifically for T12 and other fluorescent lamps
Page 9 of 10
BUILDING UTILITIES
ACOUSTICS AND LIGHTING / ILLUMINATION
ASSIGNMENT No. 1 SOUND WAVE
Define
PITCH and FREQUENCY
DECIBEL
SOUND ABSORPTION COEFFICIENT (SAC)
SOUND TRANSMISSION CLASS (STC)
SOUND INTENSITY
SOUND TRANSMISSION LOSS (TL)
SOUND PRESSURE
SOUND PRESSURE LEVEL
DOLBY NOISE REDUCTION
SOUND POWER
ASSIGNMENT No 1:
Provide pictures and descriptions about the topic below
RESEARCH No. 1
Living Areas
Types of Light Fixtures applicable for
SOUND PRESSURE LEVEL
LOUDNESS
VIBRATION
Dining Areas
T&Bs (middle-income group only)
REVERBERATION
RESEARCH No. 1
TYPES OF VIBRATION ISOLATORS AND DAMPENERS
ASSIGNMENT No. 2 REFLECTION and ABSORPTION
Define
REFLECTION
City Halls
Conference Rooms
Lobbies for Health Centers
ASSIGNMENT No. 2
TYPES OF LIGHTS or LAMPS (Provide pictures and Descriptions)
INCANDESCENT BULB
DIFFUSION
FLUORESCENT TUBE
DIFFRACTION
HIGH-INTENSITY DISCHARGE (H.I.D.) LAMPS
ECHOES
FLUTTER ECHO
RESEARCH No. 2
For additional Learning Comparative Analysis (CFL vs. LED)
FOCUSED REFLECTIONS
ELLIPSE
PARABOLA
ROTUNDA EFFECT
ANTI-FOCUSING
SOUND ABSORPTION and SOUND ISOLATION
RESEARCH No. 2
NOISE REDUCTION COEFFICIENT (NRC)
Page 10 of 10