building systems III 2nd exam

Color temp

describes how a lamp appears when lit/ lighted- measure in degrees kelvin (K)

- The higher the temperature the whiter the light

- The lower the temperature the warmer the light

color rendering

expresses how colors appear under a given light source

- A shade of red will appear lighter/darker, bluer/orange depending on the spectral properties of the light

color rendering index

is an indication of how similar an object color is rendered by a non-incandescent source relative to a specific kelvin temperature on the black body line

• The higher the CRI the better the colors will appear

• 100 is the maximum CRI and is an incandescent source

Color constancy

feature of the human color perception system which ensure that the perceived color of object remains relatively constant under varying illumination conditions

the measure of illumination

in footcandle or lux

lighting schedule

detailed document that outlines the lighting design, installation, and control requirements for a building or space.- fixture type, location, wattage, voltage, control options, and adjustments

lumen

- is the rate a light source emits light energy/ they measure the total amount of light coming from a lamp (more lumens=brighter)

candle power

describes the intensity of the light source and is measured in candles

LUX

the SI system of units for everywhere but the USA (footcandles)

Types of HID sources

metal halide, other MH, high pressure mercury, high pressure sodium, low pressure sodium

discharge lamp

type of light source that produces light by passing an electric current through a gas, which ionizes and emits visible light rather than a glowing hot solid tungsten filament emits the light

Ballasts

- electrical device used to regulate the current and voltage in lamps, particularly in discharge lamps such as fluorescent lights, metal-halide lamps, and sodium vapor lamps. are used in all discharge lamps in order to operate

Light design/ layering

- using different types of light for different purposes to ensure both the functionality and aesthetics of the space

after image

photoreceptors (cone cells) become over stimulated and lose the ability to adapt. The negative or reverse color will appear in its

categories of lighting

task lighting, ambient lighting, accent lighting, Decorative lighting, natural, emergency light

electrical panel schedules

an enclosure where electric power is allocated among individual circuits

main components of a conduct wire

- Hot- the hot blade is connected to a black conductor carrying 155v-120v

- Neutral- white conductor that provides a complete circuit for electron flow

- Ground- carries current only on the event of an electrical fault/ may be uninsulated in residential applications, green on commercial

conductors (wire)

materials that accommodate electron flow (transmit electricity efficiently)

- Copper is used for all duplex lighting and circuits

- Aluminum used for service wiring at service drops or buried lines

raceway

conduit

conductor insulation

thermoplastic, and thermoset

- Protects the underlying cable core from mechanical, moisture, and chemical damage during the insulation and service life – enhance flame resistance

GFI ground fault interrupter

- located in wet areas of a building, GFI breakers in the panel protect an entire circuit

transformer

super efficient machine for changing voltages, magnetic field created by the alternating current in a primary coil to induce a current in a secondary coil at a different voltage

water electricity

- Voltage = Water pressure: water stored at high level, the higher the stronger its pushed when it flows down

-Current = water flow: the amount of water moving is like the flow of electrons in a circuit

-Resistance = friction/obstacles: just as pipes and obstacles slow water down, resistance limits the flow of electrons

-Power = voltage x current: more pressure & more flow together create more power, just like a water wheel works best w/ both high water pressure & strong flow

Ohm’s law

exist around wires carrying a current, defines the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit V= I x R to find current: I = V/R to find resistance: R= V/I

types of electricity

static, normal current (AC/DC)

types of circuits

close/Open, series, parallel

series circuits

type of electrical circuit in which components (such as resistors, light bulbs, or other electrical devices) are connected end-to-end, forming a single path for the current to flow.

parallel circuits

the components are connected across the same two points, forming multiple paths for the current to flow.

electrical power

the product of voltage and current, any amount of power can be produced with enough cells

- The electrical power produced is equal to the product of the current and voltage.

- W= I x V W- power in watts I= current amperes V=voltage in volts

electrical energy

produced is equal to the power times the amount of time that the power is produced.

- E= W x H E= electrical energy in watt-hours H= time in hour

the number of watt-hours is usually very large, electrical energy is usually measured in kilowatt-hours.

- E= k X W X H 1 kw= 1000 w

short reverberation time

- (rapid rate of decay or face reduce sound reflection produces a special condition described as acoustically dead

long reverberation time

sound continues to reflect in a unimpeded fashion between surfaces an therefore decays more slowly, producing acoustically “live” spaces

reverberation

the subtle (less than .01 second) prolongation of the sound in the room caused by continued multiple reflections: reflected sound waves combine with your original sound waves to create a prolonged sound

echo

the long delayed discrete sound reflections of sufficient intensity to be clearly heard above the general reverberation on a space

sound intensity

sound pressure) the average deviation in pressure. These pressure deviations produce a sensation of hearing by causing the listener’s ear drum to vibrate

decibels

the measure of sound intensity/ measured in terms of the threshold levels at which the person can detect sounds signals at various frequencies:

different decibels

- 0db in the threshold for audibility

- 130 db is the threshold of pain

- 140 in standing near a jet engine

sound isolation

to the process of preventing the transmission of sound from one space to another. Ex: Soundproofing vs. Sound Absorption/ floating floors/

sound absorption

process of reducing the intensity of sound by capturing sound waves and converting their energy into heat. using materials that have the ability to absorb sound, rather than reflect or transmit it. Ex: acoustic foam, fiberglass, acoustic panel

Sound transmission class (STC)

evaluation & prediction of noise transmission/airborne sound through a barrier (walls or building elements)

- a rating for how well a building partition attenuates airborne sound > Rating values range from 10 – 70 > higher the value, less sound transmission occurs through material

Wall construction to reduce sound transmission

goal is to create a barrier that minimizes the passage of both airborne sounds, and structure-borne sounds

how to Wall construction to reduce sound transmission

- increase mass (triple layer of drywall, concrete or brick Etc.)

- increase insulation- fiberglass, cellulose insulation

- provide structural discontinuity

- provide isolation

- decoupling- separating layers of the wall structure to prevent vibrations from traveling through the wall directly

masking environmental noises

using sound to mask the surrounding noise instead of building walls and floors that will have a sufficiently high transmission loss (TL) Ex: white noise

reflector shapes

- convex (good distribution), flat, and Concave Reflectors (causes echoes, should be avoided)

white noise

a broad spectrum of sound energy , can be continuous or intermittent, has an equal amount of energy per Hz of bandwidth

attenuation

the gradual reduction in sound intensity as a result of distance and sound absorptive surfaces

creep

the transfer of sound along a concave surface (pantheon dome) a voice on one side of the dome can be clearly head on the opposite side

variable room absorption

treatments used to modify room acoustics by adjusting the amount of absorptive and reflective surfaces

natural amplification

phenomenon where certain materials, structures, or environments enhance or amplify sound without the use of artificial electronic equipment (like microphones or speakers).

natural amplification goals

- 1. Develop ceiling and wall forms to maximize the useful reflector surface 2. Use room finishes 3. Avoid focusing effects 4. arrange for blending of sound diffusion through faceting of major surfaces 5. Manipulate forms in a manner that prevents echo

illumination

- is the amount of light (lumens) falling on a surface and is measured in footcandles

footcandles

amount of light (lumens) falling on 1 square foot of surface

Inverse square law

as the distance of light increases, the same light energy is distributed over a greater spherical surface area- illumination is reduces

efficiency

ratio of light output to energy input OR ratio of lumens to watts

restrike time

how long it takes to reenergize a lamp that has been extinguished

brightness ratio

the difference in light levels between 2 areas in a space (determines how comfortable and functional the lighting is)great accent and task lighting but may create harsh shadows

point source light

great accent and task lighting but may create harsh shadows

spread/elongated light

provides even, comfortable lighting for large spaces

lighting circuits

a specific type of electric circuit designed to control the lighting system within a building or an area

voltage

the push that drives electrons

current

the flow of electrons

resistance

the opposition that slow down the electron flow

inductive reactance

is a measure of the opposition to the flow of alternating current (AC) through an inductor

duplex circuits

many outlets can be connected on a single circuit

bus bar

metal bar that carries current/ Two hot wires from the utility transformer are connected through 2 separate bus bars. circuit breakers ‘snap’ onto the bus bars

circuit breaker

a switch that opens to disconnect electrical power when it senses excess current

MCB

main circuit breaker , will cut off all electrical power

ampere

measure the amount of electric charge passing a point in an electric circuit per unit time

romex

trade name f or nonmetallic-sheathed cable. Consists of 2 or more insulated conductors and ground wire surrounded by moisture resist ant plastic.

airborne transmission

Direct passage of sound through openings and pores

frequency

the rate of vibration at the source or the number of complete cycles per second/ high rates of vibration=short wavelength(high sound) low vibration = longer wavelengths (lower sound)

amplitude

- the max displacement of particle to either side of its normal position during a vibration (peaks through soundwave)

compression

the point in as sound wave where the particles are at max pressure

refraction

- the point where the particles are at min pressure

diffusion

scattering of a sound wave in many directions & occurs when surface size equals wavelength of sound

diffraction

bending of sound waves around an object

Audience attenuation

the gradual reduction in sound intensity as a result of the absorptive properties of people.

flutter echo

an echo that occurs between parallel and non-parallel sound reflective surfaces when the source of the sound is between them

direct wave

- sound that reaches the listener w/out reflection from another surface

reflected wave

- sound that is received by the listener after the direct wave and after the wave is reflected by another surface