PDX_24_Lighting 2 Flashcards by Dickinson Donner

A light source in the field of vision

That causes interference/distractions with a visual task

Direct glare

How well did you know this?

Not at all

Perfectly

Extreme contrast in late

difference in brightness levels

Glare

How well did you know this?

Not at all

Perfectly

Zone for direct glare is the area above 45° angle from the light source

Critical glare

How well did you know this?

Not at all

Perfectly

Or like tours is reflected from a viewing service into the high and interferes with the viewing task

Reflective glare

How well did you know this?

Not at all

Perfectly

Annoying pain caused by high luminance is in a field of view (most common cause our windows and luminaires)

Discomfort glare

How well did you know this?

Not at all

Perfectly

Flexion which partially or totally scares the details to be seen by reducing contrast. The common problem with specular surfaces.

Veiling reflection

How well did you know this?

Not at all

Perfectly

The rating that indicates the percentage of people that will find the given discomfort glare acceptable. 70% is the minimum, else it’s time to fix it.

Visual comfort probability (VCP)

How well did you know this?

Not at all

Perfectly

The amount of light produced versus the power input (lumens/watt)

Efficacy

How well did you know this?

Not at all

Perfectly

Ratio of indoor illuminance to available outdoor luminance

Daylight factor (DF)

How well did you know this?

Not at all

Perfectly

The light reflected from exterior obstruction excluding the ground reflected light

Externally reflected components (ERC)

How well did you know this?

Not at all

Perfectly

Product of visible transmittance multiplied by the window to wall ratio. An EA of .20-.30 provides good day lighting.

Effective aperture (EA)

How well did you know this?

Not at all

Perfectly

Set minimum standards for energy efficiency on incandescent and fluorescent lighting

Insert date!

Energy policy act (EPACT)

How well did you know this?

Not at all

Perfectly

Daylighting analysis method that produces a family of daylight factor contours with in a room rather than individual daylight factors at specific points

Graphic day lighting design method (G DDM)

How well did you know this?

Not at all

Perfectly

Device for giving light

Lamp

How well did you know this?

Not at all

Perfectly

A complete light fixture including lamps

Luminaire

How well did you know this?

Not at all

Perfectly

Overhang that’s exterior, interior, or both, used with the clerestory to reflect light up on to the ceiling and reduce direct flight adjacent to the window

Light shelf

How well did you know this?

Not at all

Perfectly

0.2 x (window head height into room)

Daylight factor

How well did you know this?

Not at all

Perfectly

5 x (window head height into room)

2. 0 x (window head height into room with light shelf)

Effective daylight zone

How well did you know this?

Not at all

Perfectly

2.5 x the head height of the window (head height of the window above the desk playing)

Workplane daylight illuminance

How well did you know this?

Not at all

Perfectly

Electric lighting in non-residential buildings uses approximately this percentage of total electric energy

25%-60%

How well did you know this?

Not at all

Perfectly

The greatest challenge and lighting a commercial office space is providing adequate lighting for very visual tasks while,

Avoiding glare.

How well did you know this?

Not at all

Perfectly

Number used when estimating the maximum Energy used per square feet

2.3 W per square foot

How well did you know this?

Not at all

Perfectly

“When they have a choice, people will always gravitate to those rooms which have light on two sides”

Christopher Alexander’s “pattern language”

Also termed ‘bilateral light’

How well did you know this?

Not at all

Perfectly

Daylighting qualifies for a lead credit if a day late factor of __% in __% of all occupied spaces is achieved.

Daylight factor of 2% in 75% of all occupied spaces

Acceptable daylighting factor for typical office work

1.5-2.5%

Acceptable daylighting factor for reading/Handwork

2.5-4.0%

Acceptable daylighting factor for drafting/fine Handwork

4.0-8.0%

The standards sky design condition established by the Commission Internationale d'Eclairage (CIE) for daylight and calculations is:

Completely overcast sky

At a solar altitude of 30°, one can expect at daylight illuminance of about __lux with no direct sun and __lux with direct sun.

10,000 lux with is no direct sun, and 40,000 lux with direct sun

The skylights allow glass to face north for illumination not south for solar heat gain

Sawtooth skylights

Recommended horizontal to vertical aluminates ratio for general diffuse light is:

2.5:1

In general with his side lighting system any interior area more than __ feet from a window will need to be electrically lit.

More than 30 feet from a window

Incandescent bulbs have this type of filament

Tungsten

A tungsten filament is placed within a sealed bulb containing

An inert gas

Incandescent bulbs produce about this much waste because of heat production

90% waste And have a short lamp life

Incandescent bulbs have a short lamp life of about

700–1000 hours

This bulb family contains an inert gas AND halogen. Uses a fused quartz envelope that allows for higher temperature. A chemical reaction takes place pulling the tungsten from the wall of the glass back to the filament, extending its life.

Tungsten halogen incandescent bulb

Glass tube holds mixture of inert gas and low-pressure mercury vapor. Uses a ballast to supply proper starting and operating voltages, limiting the current. Advantages are high efficacy, about 80 lm per watt, low initial cost, long life, and dimmable.

Fluorescent bulb

In fluorescent bulbs, there are classes denoting noise and heat ranging from:

Class A is good for quiet areas and | Class F is acceptable for noisy areas

A lamp within a lamp that runs at a very high voltage. An electrical arc is struck across tungsten electrodes in a glass tube filled with gas and metals. Metals produce the light once they are heated to a point of evaporation. Disadvantage is that they produce a light that is not flattering to human skin, so not used for commercial/retail/residential applications.

High intensity discharge (HID)

Strands of glass about the diameter of a human hair. Hundreds/thousands bundled into cables. Transmit light signals over long distances.

Fiber optics

Set minimum standards for energy efficiency on incandescent and fluorescent lighting.

Energy policy act (EPACT)

90-100%light output directed to ceiling and upper walls. Has to bounce off for horizontal plane. 12-18 inches from ceiling minimum. Uniform lighting, lack shadows, Low brightness, and highly diffuse.

Indirect Offices, lounges, waiting areas

60–90% directed upward. 10% – 40% directed downward. Monotonous system.

Semi indirect Offices, lounges, waiting rooms, corridor

Equal distribution up and down. 12" minimum from ceiling. Efficient system

Diffuse/direct – indirect Get for classrooms, standard office workspaces, merchandising areas

60–90% directed downward 10–40% directed upward. Inherently efficient, shadowing minimized, pleasant.

Semi direct Offices, classrooms, shops, working areas

Light directed downward. Ceiling illumination floor and furnishing reflection. Low surface illumination, typically requires perimeter lighting. Sharp, theatrical atmosphere.

Direct Highlights, local, supplemental lighting, and privacy atmosphere if concentrated

Most commonly used for residential and commercial. And ceilings where not sufficient space above ceiling to recess, and existing ceilings.

Surface mounted

Residential /commercial. Includes luminist ceiling when entire ceiling is made of lighting.

Recessed fixtures

Dropped below level of ceilings, hanging. | Used for indirect systems and where light sources need to be closer to task area.

Suspended fixtures

Typical efficacy: Incandescent

12 lumens/watt

Typical efficacy: Fluorescent

55 lumens/ watt

Typical efficacy: Metal halide

90 lumens/ watt Good for libraries

Typical efficacy: High-pressure sodium

90 lm/watt Streetlights

Typical efficacy: Sunlight

115 lm/watt

Minimum lighting level required at emergency area

One footcandle at floor level Illuminated exit signs are required

The shield of metal, wood or plastic used to screen a light source from normal ankles viewing.

Baffle

The device used in fluorescent and H ID luminaries. Supply controlled voltage to heat lamp filaments in preheat and rapid start circuits. Limit the lamp current wants the lamp is started.

Ballast