Light Concept Flashcards
(42 cards)
How many adults have chronic sleep disorders?
50-70 million
What specific part of the body acts as a main internal clock that synchronizes with clocks in peripheral tissues and organs?
Suprachiasmatic nucleus
What 6 health risks are sleep deprivation linked to?
- diabetes
- obesity
- depression
- heart attack
- hypertension
- stroke (ictus)
Rods (Photoreceptive Cells) facilitate what type of vision?
- peripheral vision
- dim lighting (luce soffusa)
- green-blue sensitivity
Cones (Photoreceptive Cells) facilitate what type of vision?
- color perception
- daytime light
- green-yellow
What are ipRGCs (Photoreceptive Cells) and what type of vision?
Intrinsically Photosensitive Retinal Ganglion Cells
- See light over long-term
- Used in circadian rhythm
- Sensitivity to teal blue
What are external cues (stimoli) called, including light, that align physiology to solar day?
Zeitgebers
(circadian photo entrainment)
Light exposure in the late night/early morning (4-6am) leads to ____.
phase advance - shifts our rhythms forward
Light exposure in the late afternoon/early night (4-6pm) shifts our rhythms ____.
backward - phase delay
F53 - Visual Lighting Design (Visual for Focus, Brightness Management)
p1 a- On workstations ambient light levels of ____ lux is sufficient, as measured at __ inches above the floor.
p1 b - Ambient light system needs to be zoned in independently controlled banks no larger than ____ m2 or ___% of open floor area
p1 c- If ambient light is below 300 lux, then task lights providing ___ to ___ lux need to be provided at work stations
p1a-
215 lux (30 inches)
p1b-
46, 5 m2 (500 ft2) or 20% of floor area
p1c-
300-500 lux
F53 - Visual Lighting (Visual for Focus, Brightness Management)
p 2 - A narrative is provided that describes how 2 of 4 of the following will be considered:
- brightness contrasts adjacent and non-adjacent spaces
- brightness contrasts main rooms and ancillary spaces
- brightness contrasts in the same room such as desk surface and computer screen
- how brightness is distributed on the ceiling
F54 - Circadian Lighting Design (Melanopic)
What is EML and what is the desired level? Which requirements must be met (one of the two)?
Equivalent Melanopic Lux - A unit of measure of biological effect of light on humans melanopsins
EML = L*R (lux*ratio melanopic)
One of the two:
- verify that > 200 EML are provivded for 75% workstations, measured on 1,2 m (4’) above floor, 4 hrs/day
- verify > 150 EML are provided for all workstations by the electric lights on the vertical plane forward occupant’s view
F54 - Circadian Lighting Design (Melanopic)
Standard to refer confirming that maintained illuminance will be adequate on vertical surfaces
ANSI/IES American National Standard Practice for Office Lighting (RP-1-12)
F55. Electric Light Glare (Luminaire Shielding, Glare Minimization)
p1 - lamp shielding reqs to reduce glare (4 levesl)
Luminance of the lamp (cd/m2):
< 20k = no shielding
20k to 50k = 15° (degrees of the shielding)
50k to 500k = 20°
> 500k = 30°
F55. Electric Light Glare (Luminaire Shielding, Glare Minimization)
p2 - Workstations, desks must met one of the the following requirements (2)
- Luminaires more than 53° above the center of view have luminances < 8,000 cd/m².
- UGR < 19 for workstations, desks and other seating areas
UGR is a level of glare discomfort
F56 - Solar Glare (View window, Dayligth (window) Management)
p1 - For glazing of view window (< 2,1 m - 7 ft above floor) which are the possible (3) options?
p2 - For glazing of daylight window (> 2,1 m - 7 ft above floor) which are the possible (5) options?
p1-
a. interior window shading or blinds (manual or automatic control)
b. exterior shading systems (manual or automatic control)
c. variable opacity glazing (reduce 90% the transmissivity)
p2-
a. interior window shading or blinds (manual or automatic control)
b. exterior shading systems (manual or automatic control)
c. variable opacity glazing
d. interior light shelves
e. a film of micro-mirrors
F57 - Low-glare Workstation Design
Computer screens at desks located within ____ from windows should be orientable of ____ degrees perpendicular to window plane and overhead luminaires_________
(Avoidance direct reflection)
4,5 m (15 ft)
20 degrees
not be directed at computer screen
F58 - Color Quality (Color Rendering Index CRI)
All electric light to accurately oirtrat colors should meet the following (2):
CRI Ra (R1-R8) > 80
CRI R9 > 50
CRI is a comparison of the appearance of 8 to 14 colors under a light blackbody source
F59 - Surface Design (Surface Reflectivity)
What are the Light Reflectance Value (LRV) limits for: ceilings, wall, furniture?
Ceilings - LRV 0.8 for 80% of surface
Walls - LRV 0.7 for 50%
Furniture - LRV 0.5 for 50%
LRV is like Albedo with value from 0 (nero) to 1 (bianco)
If you want to promote alertness and activity in a workspace, should you pick a surface with a high or low LRV?
Higher LRVs mean they reflect more light
F60 - Automated Shading and Dimming (Automated sunlight control, Responsive light control)
p1 - All windows larger than ___ have shading devices that automatically engage when light sensors indicate possible glare at workstations
p2 - All fixtures except decorative fixtures are programmed to automatically dim to level ___when unoccupied.
Fixtures are programmed to dim____as daylight levels increase
p1-
0,55 m2 (6 ft2)
p2-
20%
continuously
F61 - Right to light (Lease depth, Windows access)
p1- ___% of ALL regularly occupied spaces must be within ___ of windows
p2 - ____% of workstations are within ____of an atrium/window (2 standards)
p1-
- 75% occupied spaces→ within 7,5 m (25 ft)
p2-
- 75% workstations → within 7,5m (25 ft)
and - 95% workstations → within 12,5 m (41 ft)
F62 - Daylight Modeling
What describes the minimum sunlight levels?
What describes the maximum sunlight levels?
(Healthy sunlight exposure)
Minimum
sDA per > 55% spaces
sDa = ≥ 300 lux per 50% of period analysed
(Spacial Daylight Autonomy )
- *Maximum**
- *ASE per < 10% spaces**
ASE = ≥ 1000 lux for 250 hours annually
(Annual Sunlight Exposure)
ovvero 10% ASE
F63 - Daylighting Fenestration (Window sizes, Windows Transmittance, Uniform Colour Transmittance)
p1 a - window- wall ratio on the external elevation of a building?
p1 b - How much of window area should be “daylight windows”?
a. 20-60% (greater than 40% glass requires external shading)
b. 40 - 60%
