NCIDQ IDFX QUESTIONS AND
CORRECT ANSWERS
planning concepts in regard to noise ✔️✔️1. plan similar use areas next to each other
2. use buffer spaces such as closets and hallways to separate noise-producing spaces whenever
possible
3. stagger doorways in halls and other areas to avoid providing a straight line path for noise
4. locate furniture and other potential noise-producing objects away from the wall that is
separating spaces
5. minimize area of the common wall between the 2 rooms where a reduction in sound
transmission is desired
6. avoid room shapes that reflect or focus sound
noise reduction coefficient (NRC) ✔️✔️single number rating of the average sound absorption
of a material over a limited frequency range
--range from 0 to 1.0, where acoustical ceiling tiles are usually a .65-.90
*.85 or higher is recommended in open-plan offices (for ceiling tiles)
speech range absorption (SRA) ✔️✔️rating more closely represents frequencies of speech and
may be BETTER rating to use in evaluating and selecting CEILING tiles SPECIFICALLY
,ceiling attentuation class (CAC) ✔️✔️single number measure of the transmission loss through
CEILING TILES between 2 closed rooms where there is NO wall or other barrier ABOVE the
suspended ceiling
--most acoustical ceiling tiles have ratings between 30-35db (improved by using composite tiles
with gypsum wallboard backing)
2 methods used to measure speech privacy in open offices ✔️✔️1. articulation class: how
effective a CEILING is in absorbing sound reaching it from over LOW PARTITIONS (uses 9'
high ceiling and 60" high partitions)
2. articulation index: measures the performance of ALL the elements of a particular
CONFIGURATION working TOGETHER, including ceiling absorption, space dividers,
furniture, light fixtures, partitions, background masking systems, and HVAC sound
--all predicts the intelligibility of speech for a group of talkers and listeners
--rating between 0 and 1 (1 = no privacy)
--confidential speech = below .05
--normal speech: between .05 and .2
--UNACCEPTABLE level of privacy = .30 and ABOVE
extent of direct glare problem depends on what? ✔️✔️1. brightness of the source
2. its position
3. the background illumination
4. the adaptation of the eye to the environment
,critical zone for direct glare ✔️✔️area above 45 degrees from the light source
reflected glare ✔️✔️occurs when a light source is reflected from a viewed surface into the eye
veiling reflection ✔️✔️reflected glare interferes with the viewing task
--caused by a complex interaction of a light source and brightness, position of the task,
reflectivity of the task, and position of the eye
--to correct: move either the task or light source so as to change the relationship OR provide
general background illumination AND specific task lighting that can be moved easily
how to fix reflected glare ✔️✔️decrease the contact between the task and its background
brightness rations ✔️✔️-3:1 = between task and IMMEDIATE backgrounds
-5:1 = between the task and NEARBY general surroundings
-10:1 = between task and more REMOTE surroundings
light quality factors ✔️✔️1. direct glare
2. reflected glare
3. contrast
4. uniformity
5. color
6. efficacy (ability to produce a desired/intended result; how well a light source produces visible
light)
, incandescent ✔️✔️-low efficacy
-2700-2800K
*-100 CRI
-Low lamp life
-inexpensive, compact, easy to dim, can be repeatedly started without a decrease in lamp life &
have a warm color rendition
DISADVANTAGES: low efficacy, short lamp life, and high heat output
elliptical reflector lamp ✔️✔️more efficient type of incandescent because it focuses the light
beam at a point slightly in front of the lamp before it spreads out (slightly smaller spread that that
of an R lamp)
parabolic alluminized reflector (PAR) ✔️✔️tighter spread than regular incandescent
--* second narrowest beam spread
Multifaceted Reflector (MR-16) ✔️✔️low voltage, multifaceted mirror reflector
--several angles of beam spread available
***have the NARROWEST beam spread of 4 types
tungsten halogen ✔️✔️incandescent light, but with a small amount of halon
CORRECT ANSWERS
planning concepts in regard to noise ✔️✔️1. plan similar use areas next to each other
2. use buffer spaces such as closets and hallways to separate noise-producing spaces whenever
possible
3. stagger doorways in halls and other areas to avoid providing a straight line path for noise
4. locate furniture and other potential noise-producing objects away from the wall that is
separating spaces
5. minimize area of the common wall between the 2 rooms where a reduction in sound
transmission is desired
6. avoid room shapes that reflect or focus sound
noise reduction coefficient (NRC) ✔️✔️single number rating of the average sound absorption
of a material over a limited frequency range
--range from 0 to 1.0, where acoustical ceiling tiles are usually a .65-.90
*.85 or higher is recommended in open-plan offices (for ceiling tiles)
speech range absorption (SRA) ✔️✔️rating more closely represents frequencies of speech and
may be BETTER rating to use in evaluating and selecting CEILING tiles SPECIFICALLY
,ceiling attentuation class (CAC) ✔️✔️single number measure of the transmission loss through
CEILING TILES between 2 closed rooms where there is NO wall or other barrier ABOVE the
suspended ceiling
--most acoustical ceiling tiles have ratings between 30-35db (improved by using composite tiles
with gypsum wallboard backing)
2 methods used to measure speech privacy in open offices ✔️✔️1. articulation class: how
effective a CEILING is in absorbing sound reaching it from over LOW PARTITIONS (uses 9'
high ceiling and 60" high partitions)
2. articulation index: measures the performance of ALL the elements of a particular
CONFIGURATION working TOGETHER, including ceiling absorption, space dividers,
furniture, light fixtures, partitions, background masking systems, and HVAC sound
--all predicts the intelligibility of speech for a group of talkers and listeners
--rating between 0 and 1 (1 = no privacy)
--confidential speech = below .05
--normal speech: between .05 and .2
--UNACCEPTABLE level of privacy = .30 and ABOVE
extent of direct glare problem depends on what? ✔️✔️1. brightness of the source
2. its position
3. the background illumination
4. the adaptation of the eye to the environment
,critical zone for direct glare ✔️✔️area above 45 degrees from the light source
reflected glare ✔️✔️occurs when a light source is reflected from a viewed surface into the eye
veiling reflection ✔️✔️reflected glare interferes with the viewing task
--caused by a complex interaction of a light source and brightness, position of the task,
reflectivity of the task, and position of the eye
--to correct: move either the task or light source so as to change the relationship OR provide
general background illumination AND specific task lighting that can be moved easily
how to fix reflected glare ✔️✔️decrease the contact between the task and its background
brightness rations ✔️✔️-3:1 = between task and IMMEDIATE backgrounds
-5:1 = between the task and NEARBY general surroundings
-10:1 = between task and more REMOTE surroundings
light quality factors ✔️✔️1. direct glare
2. reflected glare
3. contrast
4. uniformity
5. color
6. efficacy (ability to produce a desired/intended result; how well a light source produces visible
light)
, incandescent ✔️✔️-low efficacy
-2700-2800K
*-100 CRI
-Low lamp life
-inexpensive, compact, easy to dim, can be repeatedly started without a decrease in lamp life &
have a warm color rendition
DISADVANTAGES: low efficacy, short lamp life, and high heat output
elliptical reflector lamp ✔️✔️more efficient type of incandescent because it focuses the light
beam at a point slightly in front of the lamp before it spreads out (slightly smaller spread that that
of an R lamp)
parabolic alluminized reflector (PAR) ✔️✔️tighter spread than regular incandescent
--* second narrowest beam spread
Multifaceted Reflector (MR-16) ✔️✔️low voltage, multifaceted mirror reflector
--several angles of beam spread available
***have the NARROWEST beam spread of 4 types
tungsten halogen ✔️✔️incandescent light, but with a small amount of halon
