Light intensity on a surface from the light source

Lux formula

Is a procedure for determining the average maintained illuminance on the working plane in a room

Number of lamps

Desired illumination level

Lamp lumen

Area of room

This method presupposes that luminaires will be spaced so that uniformity of illumination is provided.

This is often used by architects, specially if the type of lamp to be used remain undecided.

the art and technique of designing spaces, structures and mechanical systems to meet hearing needs.

goal of architectural acoustics

Essential Elements of Architectural Acoustics

Essential Elements of Architectural Acoustics: Room Acoustics

Essential Elements of Architectural Acoustics: Sound Reinforcement System

Essential Elements of Architectural Acoustics: Sound Isolation

Essential Elements of Architectural Acoustics: Mechanical System Noise Control

an oscillation in presence of the atmosphere which is capable of being detected by the human ear.

It is a form of energy propagated in waves that continues to subsist until filtered through a material turning into heat by friction.

the sensation produced through the ear resulting from fluctuations in the pressure of the air.

The nature of sound, in order to be heard, requires the following elements:

normally a vibrating body, which converts some other form of energy into vibration. The source can be made quitter.

often used as a generic term for devices used in converting some form of energy into sound such as loudspeakers and microphones.

any substance that allows the vibration to be transmitted in the form of a wave motion. It can be made to transmit more or less sound.

Sounds that are transmitted by air are called:

Sounds that are transmitted through solid bodies are called:

pertains with the human ear.

The types of sound are:

can be classified as ordered sound since it is integrated.

can also be considered as ordered sound since it is also integrated.

is classified as disordered sound

are longitudinal waves.

They can be pure tone or a complex sound.

is sound dominated by energy in a single frequency, and is described by a single smooth sine curve.

can only be produced electronically

are those of speech, music and noise.

the full circuit by the particle.

the number of complete cycles per second, measured in hertz (Hz).

the maximum displacement of a particle.

the time required for one complete vibration, measured in seconds per cycle.

the distance a sound wave travels during one cycle of vibration

The Properties of Sound

is the speed of sound that varies greatly according to the medium the waves travel in and slightly according to the temperature of the medium.

is often referred to by a term borrowed from musical concepts – Pitch.

The higher the frequency,

approximate frequency range of a healthy person

is its number of vibrations in cycles per second, also known as Hertz (Hz).

Humans are most sensitive to sounds having significant energy in the :

Low frequency sounds of about 16 to 500 Hz are called

high frequency sounds of 1,000 to 8,000 Hz are referred to as

also known as sound intensity, is its loudness or impact of its pulsating waves against eardrums, measured in decibels (dB).

This is the most often used description and measurement of sound relative to human sensitivity as to pressure.

Loudness Level of Common Recognized Sounds: Painful - 140 dB

Loudness Level of Common Recognized Sounds: Painful - 130 dB

Loudness Level of Common Recognized Sounds: Painful - 120 dB

Loudness Level of Common Recognized Sounds: Deafening - 110 dB

Loudness Level of Common Recognized Sounds: Deafening - 100 dB

Loudness Level of Common Recognized Sounds: Very loud - 90 dB

Loudness Level of Common Recognized Sounds: Very loud - 80 dB

Loudness Level of Common Recognized Sounds: Loud - 70 dB

Loudness Level of Common Recognized Sounds: Loud - 60 dB

Loudness Level of Common Recognized Sounds: Moderate - 50 dB

Loudness Level of Common Recognized Sounds: Moderate - 40 dB

Loudness Level of Common Recognized Sounds: Faint - 30 dB

Loudness Level of Common Recognized Sounds: Faint - 20 dB

Loudness Level of Common Recognized Sounds: Very Faint - 10 dB

Loudness Level of Common Recognized Sounds: Very faint - 0 dB

ROOM ACOUSTICS

The following simplification of acoustical principles will enable you to evaluate how much acoustical material is required.

The loudness of direct sound waves to a listener determined by:

Almost imperceptible

Just perceptible

Clearly noticeable

Twice (or ½ ) as loud

Very much louder (or quiter)

When a sound wave strikes a surface such as a floor, wall, or ceiling

Sound travels about _____ miles per hour in all directions.

The multiple reflection of sound waves has two effects on acoustics:

Reflected waves will continue ricocheting between room surfaces losing only a fraction of power by absorption at each reflection.

time measured in seconds that a sound average loudness can be heard before it becomes completely inaudible under quiet conditions.

The maximum reverberation time for clear speech

A distinct repetition of direct sound

a unit of sound absorption equivalent to one square foot having a coefficient of absorption of 1.00.

Defined as the flow of light

The measure of success of doing this is called ______ and is measured in lumens per watt (lm/W)

the quantity of light emitted by a light source, regardless of direction or distribution. It is synonymous to flow in plumbing.

the brightness of an illuminated or luminous surface as perceived by the human eye.

The visible radiant intensity in a particular direction

gives a nearly uniform, glare less illumination in the room. This type is useful in spaces with video display terminals

Directs all light to the ceiling

Should be used only with white or near white ceilings

It has soft and uniform light but lacks emphasis

Suitable for high ceilinged rooms and for places where ceiling heights abruptly change.

Located over work areas to provide higher level of light directly below

Excellent for niches over sofas, pianos, built-in desks

Used with large mirrors and countertop lavatories. Length is coordinated with size of mirror

Add luxury touch with attractively decorated bottom diffuser

Is always used at windows, usually with draperies

Provides uplight that reflects off ceiling for general lighting and downlight for drapery accent

Totally luminous ceiling provide skylight effect very suitable for interior rooms or utility spaces such as kitchens, baths and laundries.

With decorative diffuser patterns, more decorative supports and color accents, they become acceptable for many other living spaces such as family rooms, dens, etc.