Fundamentals of Lighting & Acoustics

Nomenclature see p19-2

1) what is "transmittance?"
2) what is clear glass transmittance
3) how does light pass thru clear mat.'s?
4) what is the "reflectance" or "reflectance coefficient?"

1) what is "specular reflection?"
2) what is "diffuse reflection?"
3) what is "combined specular & diffuse reflection?"

*be familiar w/ relationships
1) "candlepower" is the unit of luminous intensity approx. equal to:
2) "illuminance" is the density of luminous flux incident on a:
3) "lumen" (lm) is the unit of luminous flux equal to the:

1) on a sphere, 1ft radius (an area of 1sqf) will subtend an angle of:
2) b/c area of a sphere is 4 π, a source of 1 candlepower produces:
3) "luminance" is the luminous flux per unit of projected (apparent) area &:

1) luminance takes into acct what properties of mat.'s as well as:
2) ^so, 100fc striking a surface w/ 50% reflectance would result in:
*in metric: 100 lux striking a 1 sq m surface w/ 50% reflectance would result in:

1) "luminous intensity" is the solid angular flux density in a:
2) illuminance target for population btwn ages 25-65 is std, but when 50% abv 65 :
4) 50% blw 25:
3) what does ASHRAE/IESNA Std. 90.1 set a max on?

1) what is considered "direct glare?"
2) what is "visual comfort probability" (VCP)?

1) what is the critical zone for direct glare?
2) how can direct glare problems be solved
3) "reflected glare" occurs when a light source is:

1) what is "veiling reflection?"
2) how can it ^ be corrected?
3) contrast ratio for task & adj surrounds:
4) task & more remote darker surfaces:
5) task & more remote lighter surfaces:

1) oth than daylight, what are the 4 primary types of light sources?
2) "efficacy" is the ratio of luminous flux emitted to the:
3) efficacy is a measure of a light's:
4) why is the amt of heat generated by a light source important?

*see table19.1 for light characteristics
1) how does an incandescent lamp produce light?
2) what does the code A-21 mean?
3) advg's of incandescent lamps:

1) disadvg's of incandescent lamps:
2) how does the tungsten halogen incandescent lamp differ from the typ?

1) what is unique about the halogen bulb?
2) reflector (R) & parabolic aluminized reflector (PAR) lamps contain a:
3) elliptical reflector lamps (ER) are improved R lamp version & prvd a more efficient:

1) low-voltage miniature reflector lamps (MR) are small:
2) "fluorescent lamps" contain a mix of inert gas & low-pressure mercury vapor, & when energized light is produced by:

1) advg's of fluorescent lamps:
2) what new fluorescent is smaller & brighter & now has downlights w/ reflector designs?
3) what are the 3 types of fluorescent lamps?

1) preheat-lamps don't carry current unless in operation & don't begin:
2) rapid-start lamps maintain a constant low current in the cathode that:
3) instant-start lamps maintain a constant voltage high enough to:

1) every gaseous discharge lamp (including fluorescents) has a ballast, what is it?
2) "magnetic ballasts" are constructed from laminated steel plates wrapped w/
3) "electronic ballasts" are solid-state electronics that operate at:

1) "multilevel ballasts" 2 or 3 level are used:
2) "energy-saving ballasts" reduce the total wattage of the lamp-ballast combo by:
3) what are 2 oth types of ballast?

BALLAST EFFICIENCY RATINGS
1) a "ballast factor" (BF) is the ratio of light output of a lamp when operated on:
2) "ballast efficacy factor" (BEF) is the ratio of the ballast factor is:
3) BEF compares efficacy of diff. ballasts when used w/ the same kind & # of:
4) "power factor" is how effectively ballast converts:

1) noise for ballast is rated in letters A-F, which is loudest?
2) F40T12WW / RS describes a fluorescent lamp, what does it mean?
3) Energy Star program req.'s not using a st.d Edison screw based, but a:

1) "high-intensity discharge lamps (HID)" include:
2) in a HID mercury vapor lamp, an electric arc is passed thru:
3) how can color be altered in mercury lamp?
4) are HID mercury lamps good in efficacy?

1) "metal halid lamps" are sim. to mercury ones except what has been added to tube?
2) what are their advg's?
3) & the disadvg's?
4) what are the 3 types of outer bulbs used to protect ppl from ultraviolet light on HIDs

1) a new type, "ceramic metal halide lamps (CMH)" use a:
2) what are the disadvg's?
3) & the advg's?

1) a "high-pressure sodium lamp" produces light by:
2) advg's of HPS lamps include:
3) & the disadvg's?
4) a "low-pressure sodium lamp" is better or worse than a HPS lamp?

1) all HID lamps need time to cool & warm up again after shut off, mercury-vapor needs:
2) metal halide lamps need:
3) HPS lamps need:

1) a "light-emitting diode (LED)" is a:
2) what is the basic unit of an LED?
3) 2 other types of LEDs include:
4) advg's of an LED include:

1) what are the disadvg's of LEDs?
2) LEDs are replacing which type of light?
3) besides 4 common types of lamps, what are the 3 others?
4) neon & cold-cathode use a glass tube filled w/:
5) fiber-optics carry light from a remote light source to area to be illuminated, used typ when:

FUNDAMENTALS OF ACOUSTICS
*study definitions p19-11
1) (IIC) "impact insulation class" is a single-# rating of a:
2) (STC) "sound transmission class" is a barrier's abililty to reduce sound over:
3) (TL) "transmission loss" is the difference in decibels btwn the:

1) the velocity of sound depends on the:
2) in air at sea level velocity =
3) frequency if the number of:
4) how are frequency (f), velocity (c), & wavelength (w) related? what is the equation?

1) power (P) is the quantity of:
2) in free space, a pt source emits waves in:
3) ^so sound intensity (I) at given pt at a distance of "r" from the source is = to:

1) if sound intensity is wanted in watts per sq cm & radius is given in feet, use equation:

1) "inverse square law" says the intensity of a force or energy (like a sound wave) at a given pt is inversely proportional to the square of the distance from the source of that energy, what is equation?

1) hearing is proportional to the:
2) sound intensity is measured in:
3) how do humans exp. 0 dB vs 130 dB
4) what is the equation that expresses this relationship ^?
*see table19.2 for common sound intensities

LOUDNESS table 19.3
change in intensity level:
1) 1dB =
2) 3dB =
3) 5dB =
4) 6dB =
5) 10dB =
6) 18dB =
7) 20dB =

*table19.4: guideline of addition of decibels to w/in 1% accuracy b/c decibels are logarithmic they can't be added directly
-diff btwn 2 values is:
1) 0 or 1 dB
2) 2 or 3 dB
3) 4 to 8 dB
4) 9 or more dB

*for the addition of an arbitrary # "?" of sources of identical value, use equation:

1) for a normal young healthy human ear, audible sounds range from:
2) in what range is sound of speech?
3) human ear is less sensitive to what type of frequencies?
4) for measurement & analysis, frequency range is divided into a scale of:

1) bands are identified by their center frequencies which are:
2) b/c the human ear is less sensitive to low frequencies, which modified decibel scale is used?
3) what are 2 important factors in transmission of sound?

1) 1st important concept in noise reduction is transmission loss which is the:
2) noise reduction is 2nd, it is the:

1) noise reduction is calc'd using which equation?

1) noise reduction can be increased by increasing:
2) in critical situations, transmission loss & barrier selection should be calc'd using values for:

1) when a partition includes 2 or more types of const., the combined transmission loss is found using equation:
2) if the value of the transmission loss of the individual mat.'s is known, to find value of "t" use equation:

1) noise criteria curves can be used o specify the max amt of:
*see associated noise criteria table19.5
2) NC for concert halls
3) for bedrooms, apts, hospitals
4) for private offices, sm conf. rm's
5) large offices, retail stores, restaurants
6) lobbies, drafting rm, lab work space
7) kitchens, comp. rm, maintenance

TRANSMISSION LOSS GUIDELINES
1) typ loss thru barrier increases w/ frequency of sound
2) a wall w/ 0.1% open area (cracks, holes, door undercuts) will have max loss of 30dB & w/ 1% open area 20dB
3) to determine req.'d STC barrier rating, guidelines in table19.6 can be used

*19.6 EFFECT OF STC ON HEARING
1) STC 25
2) STC 30
3) STC 35
4) STC 42-45
5) STC 45-50

1) sound intensity levels decrease ~6dB for ea. doubling of distance from source but:
2) sound absorption is used to ctrl
3) absorption of a mat. is defined by coefficient of absorption "a" which is the ratio of the sound intensity absorbed by mat. to:

1) when is an absorption coefficient considered reflective vs absorbing?
2) absorption coefficient varies w/:
3) noise reduction coefficient is the avg of:
4) sound absorption avg (SAA) has been superseding NRC, it's the avg of absorption coefficients for:

1) the total absorption of a mat. is dependent on the area of the mat. & the mat.'s coefficient of absorption per equation:

1) increasing sound absorption w/in a space will result in noise reduction per equation:

SOUND ABSORPTION GUIDELINES
1) the avg absorption coefficient should be
2) a coefficient abv 0.5 is considered:
3) mat.'s w/ higher values are suitable for
4) ea. doubling of the amt of absorption in a room results in:

1) if add.'l absorptive mat. is being added to a room, total absorption should be:
2) when adding extra absorption, an increase of 10x is approx. practical limit b/c
3) ea. doubling of absorption in a room reduces reverberation time by:

1) where is absorptive mat. more effective in large vs small rooms?
2) typ absorption increases w/ an increase in:
3) amt of absorption of a porous sound absorber (mineral wool ex) depends on:

1) "reverberation time" (T in sec.'s) is the time it takes sound levels to:
2) what is the equation?

1) reverberation time that is shorter is better for spaces that are:
*see table 19.7
2) ex time for auditoriums (speech & music) & opera halls:
3) ex time for offices, small rooms for speech: