Midterm Flashcards
Defined as the sun’s horizontal position angle, measured from the south.
Azimuth Angle
Solar position is _________ for any given time and location.
Absolutely predictable
Exterior illumination depends upon
> Solar position
Weather condition
Effects of local terrain
Cloud cover, unlike solar position, is only _________
Statistically predictable
The four basic sky conditions
> Solid overcast sky
Clear sky without sun
Clear sky with sun
Partly cloudy sky
Overcast Sky is sometimes called
Commission Internationale de I’Eclairage sky
Its has a non-uniform brightness distribution, increasing from horizon to zenith in approximately a 1:3 ratio
Overcast Sky
It is the ratio of indoor illuminance to available outdoor illuminance.
Daylight Factor
The two source components of Horizontal Illuminance
> Diffuse illumination from the sky
>Direct sunlight
It is valued from the sun as a function of solar altitude, when combined with proper portion of diffuse illuminance
Horizontal Illuminance
It is important for determining the daylight contribution of vertical, elements in skylights and it is also a major component of interior daylight.
Vertical Surface Illuminance
It is defined as the horizontal angle between a vertical plane containing the sun and a plane perpendicular to the vertical surface.
Bearing angle
A type of sky that is difficult to express mathematically because of its infinite variability of conditions.
Partly Cloudy Sky
The illumination from a partly cloudy sky is higher than of a clear sky by ___ to ___ because of additional reflected sunlight from cloudy edges.
10 to 15 %
It is the radiant power at each wavelength or band of wavelength in the visible region
Spectral power distribution
it is the physical difference of SPDs that appear to have the same color
Metamers
It is a measure of how colors of surface will appear when illuminated by a light source
Color rending index
It describes the appearance of light generated by a hot object.
Correlated color temperature
It is the other term for color temperature
Chromaticity
It is the quality attribute by which we recognize and describe colors.
Hue
It is the difference between the resultant colors of the same hue.
Brilliance or Value
It is the difference from the purity of the color.
Saturation or Chroma
A type of lamp that produces light by heating a filament
Incandescent Lamp
A type of lamp that produce light by ionizing gas through electric discharge inside the lamp
Discharge Lamp
A type of lamp that uses the phenomenon called electroluminescence to convert electrical energy directly to light
Solid-state Lamp
It is the ratio of lumens provided to watts of heat produced by a light source
Efficacy
Source with higher efficacy require ____ electrical energy to light a space or area.
Less
What are the parts of an incandescent lamp
> Bulb
Filament
Gas
Base
Halogen Lamps are sometimes called ______ lamps because its high temperature envelopes instead of the softer glass used.
Quartz lamp
A type of lamp that produce light by passing an electric current through a gas that emits light when ionized by current.
Discharge Lamps
A type of lamp that uses electric current to heat a coiled tungsten filament to produce light.
Incandescent Lamps
It is an auxiliary device that supplies voltage to the lamp’s electrodes
Ballast
What are the two types of Discharge Lamps
> High-intensity discharge
>Low-intensity discharge
What are the four types of high-intensity discharge lamps
> High-pressure mercury vapor
Metal-halide
High-pressure sodium
Xenon
A type of lamp that is a gas discharge source that contains mercury vapor at low pressure, with a small amount of inert gas for starting.
Fluorescent Lamp
What are the three types of Fluorescent lamps
Linear Fluorescent Lamp
Compact Fluorescent Lamp
Light-Emitting Diodes
