chap 13 Flashcards
a variety of switches and controls are used to manage
operation of lighting installations.
Lighting System Controls
A ________ is an electrical device that opens an electrical circuit, thereby shutting the lights off
or closing the circuit to energize the lighting installation.
switch
A ______ or group of _______ can control the lighting installation from one or multiple
locations.
switch/swithches
Three-way switches ($3) and four-way
switches (S4)
can be circuited to control a
lighting installation from two or more locations.
Two three-way switches
are required to
control a lighting installation from two
locations.
are required
to control a lighting installation from three or more locations.
Two three-way switches and one or more four-way
deactivate the lighting circuit after
a preset time has lapsed.
Automatic switches
can be used to vary the luminous flux
(lumen output) from lamps in a lighting installation.
Dimmer switches
- limit access to switches for lights and
equipment to authorized personnel.
Keyed switches
can activate a lighting circuit when a door
is open or closed (e.g., similar to a refrigerator light).
Door switches
can be used to control the time period that a lighting installation
operates.
Time clocks
Automatically control operation of a lighting installation with electronic
components that are wired into the circuitry.
Electronic timers
sense light and can be used to control night lighting in
lieu of a time clock or timer.
Photocell controls
control a lighting installation by sensing occupants in a
space and usually mounted on the wall or ceiling. Works well in interior spaces
such as classrooms and offices.
Occupancy sensors
A ___________________ offers building operators full control of multiple
lighting installations from a single location.
central lighting control system
The efficient and effective use of direct, diffuse, or reflected sunlight to provide full or
supplemental illumination for building interiors during hours of sunlight.
Daylighting
Diminishes the need for artificial light in buildings and thus saves lighting costs up to
80% (in some buildings).
Sunlight
Daylighting in buildings also typically increases space heating and cooling costs. (t or f)
f (decreases_
A combination of direct, reflected, and diffuse sunlight.
DAYLIGHT
Strikes a surface and reflects off the surface in another
direction
Reflected light
Travels in a straight line path from the sun
Direct Light
Is light that has been reflected or refracted by clouds,
glazing, or other objects
Diffuse light
a measure of how easily heat travels through an assembly of materials
Overall Coefficient Of Heat Transfer (U)
Thermal insulating ability is also measured by the _________ resistance (R):
thermal
higher R factor indicates a better insulating performance. (t or f)
t
The fraction of solar heat that is transmitted through the glazing and ultimately
becomes heat.
Solar Heat Gain Coefficient (SHGC)
The higher the SHGC, the less solar heat is transmitted through the glazing and
the greater it’s shading ability. (t or f)
f( lower the shgc)
East- and west-facing windows that receive undesirable direct sunlight in
mornings and afternoons should have lower SHGC assemblies.(t iorf)
t
Is the percentage of visible light (light in the 380 to 720 nm range) that is
transmitted through the glazing.
Visible Transmittance (VT)
Is the ratio between SHGC and VT of a single glazing
Light-to-solar Gain Ratio (LSG)
Historically, only _____ was used as a glazing material.
glass
must be designed to provide
illumination in areas where it is most needed and to do so
without adversely affecting occupant comfort.
Daylighting systems
is to increase the number
and size of glazed areas in the walls or ceilings of a
building, but simply using large glazed openings does not
ensure good daylighting.
Basic daylighting strategy
The main functions of_______ are
to bring in daylight and fresh air
windows
Is a design term that describes window size, arrangement, and
glazing type (the glass and coatings used in the window).
Fenestration
Is a fenestration arrangement in an upper story wall that
extends above one roof surface; it introduces daylight into the
ceiling area of the space.
Clerestory Window System
An_______ is an interior courtyard covered with glazing. Rooms
and spaces 8 adjoining the atrium receive daylight entering
through the glazed roof.
atrium
A ________ arrangement of several smaller windows can
provide uniform daylight illumination if properly distributed in
the space being illuminated.
fenestration
In hot climates in the northern hemisphere, the low position of the sun
produces a shallow angle and a heat gain that contributes to space
heating. (t or f)
f(cold climates)
Limit solar gains in the summer because the steep angle of the
summer sun with respect to the glass.
South-facing windows
Exposed to considerable direct sunlight during these times of
the day
East-and West – facing windows
Windows facing in these directions should only be used when
no other method of introducing daylight is possible and where
control of direct sunlight and glare is achievable
East-and West – facing windows
windows facing in this direction
provide good quality daylighting, excessive heat loss and mean
radiant temperature in the winter is a concern in cold climates.
North-facing windows
Is a transparent panel located in a roof opening that allows
direct and diffuse sunlight into the building
Skylights
Is a type of skylight system that is a raised, typically triangular
shaped, extension of a roof and that has at least one glazed
surface.
Roof Monitor
Is a passive (non-mechanical) architectural
element or mechanism that allows sunlight to
enter deep into a building.
Reflective Light Shelves
Is a type of light pipe that has a movable
mirror or light-refracting system and that
can be used to align the incoming sunlight
with the axis of the light pipe, thereby
minimizing reflection losses
Sun tracking light pipe
can be used to introduced daylight
through the roof itself
Fabric Roof Membrane
use a membrane, supported by a cable, to act as
the roof of a structure.
Tension structures
Air-supported structures
use a membrane, supported by — air
pressure, to act as the roof and walls of the structure.
