PPD Revision Study Set- Questions & Answers
Solved 100% Correct.
Drainage system for __ year storm
It is common to design drainage systems for 25-year storms; systems designed for 10-year
storms are also common.
Which sewers take precedence in planning
Sanitary sewers and storm sewers usually take precedence in planning because they depend on
gravity flow.
The invert
Lowest elevation of the existing public sewer line
Minimum slope of the building
The minimum slope of the building sewer is 0.5% to 2.0% depending on the size of the pipe.
Road slope
A road should be limited to a maximum slope of 15% for short distances, although 10% or less is
preferable. If a road does slope more than 10%, there should be transition slopes of one-half of
the maximum slope between the road and level areas.
Shading coefficient (SC)
the ratio of the solar heat gain through a particular glazing product to the solar heat gain through
an unshaded 1/8 in thick clear, double-strength glass under the same set of conditions. However,
the shading coefficient is a value that represents the glazing only, not the frame or spacer effects.
,Solar heat gain coefficient (SHGC)
The SHGC is the ratio of the solar heat gain through glazing or a window compared to the total
solar radiation incident on the glazing or window. It is expressed as a value between zero and
one.
Reflective glass
Reflective glass is clear or tinted glass coated with an extremely thin layer of metal or metallic
oxide. In insulating units, this reflective layer is placed on the inside of the exterior lite of glass.
Trees shield against wind
In general, a row of trees of a certain height will decrease the velocity of the wind between 30%
and 40% at a distance about five times the height of the trees. Trees planted next to a building
may reduce wind velocity between 20% and 60%, depending on the density of the trees. The
effect of trees on reducing wind velocity decreases greatly at about 10 times the tree height and
is negligible beyond 20 times the tree height
Equidistant horizontal projection
The equidistant horizontal projection (also known as the horizontal polar projection) plots the
path of the sun at various times of the year on a circular chart
gnomonic projection
gnomonic projection (also called a sunpeg chart) is derived from a sundial projection. It is useful
for shadow studies. A gnomonic projection is used by placing the chart next to the building
model to be studied, then placing a small peg perpendicular to the chart in the location shown.
, The model and chart are tilted in sunlight until the tip of the shadow cast by the peg intersects the
selected date and time.
Rectilinear projection
In a rectilinear projection, the solar azimuth is plotted along the horizontal axis, and the solar
altitude is found along the vertical axis
phase change materials
Phase change materials are used to avoid the overheating and wide swings in temperatures that
can occur with concrete, masonry, and water. Eutectic salts that change from a solid to a liquid at
a fairly low temperature, around 70°F, are commonly used phase change materials. They store
large amounts of heat because they also store latent heat as they undergo the phase change from
solid to liquid. At night, the heat is released as they again change state, from liquid back to solid.
Active solar system
A typical active solar system requires three components: a collector, a storage device, and a
distribution system.
Geothermal energy
Geothermal energy uses ground-source heat pumps (GSHPs). GSHPs are electrically powered
systems that work like air-source heat pumps by either extracting heat from the ground in winter
or giving off excess heat to the ground in summer. Within a GSHP, the heat from the ground is
increased through a vapor-compressor refrigeration cycle.
Main feature of a GSHP
Solved 100% Correct.
Drainage system for __ year storm
It is common to design drainage systems for 25-year storms; systems designed for 10-year
storms are also common.
Which sewers take precedence in planning
Sanitary sewers and storm sewers usually take precedence in planning because they depend on
gravity flow.
The invert
Lowest elevation of the existing public sewer line
Minimum slope of the building
The minimum slope of the building sewer is 0.5% to 2.0% depending on the size of the pipe.
Road slope
A road should be limited to a maximum slope of 15% for short distances, although 10% or less is
preferable. If a road does slope more than 10%, there should be transition slopes of one-half of
the maximum slope between the road and level areas.
Shading coefficient (SC)
the ratio of the solar heat gain through a particular glazing product to the solar heat gain through
an unshaded 1/8 in thick clear, double-strength glass under the same set of conditions. However,
the shading coefficient is a value that represents the glazing only, not the frame or spacer effects.
,Solar heat gain coefficient (SHGC)
The SHGC is the ratio of the solar heat gain through glazing or a window compared to the total
solar radiation incident on the glazing or window. It is expressed as a value between zero and
one.
Reflective glass
Reflective glass is clear or tinted glass coated with an extremely thin layer of metal or metallic
oxide. In insulating units, this reflective layer is placed on the inside of the exterior lite of glass.
Trees shield against wind
In general, a row of trees of a certain height will decrease the velocity of the wind between 30%
and 40% at a distance about five times the height of the trees. Trees planted next to a building
may reduce wind velocity between 20% and 60%, depending on the density of the trees. The
effect of trees on reducing wind velocity decreases greatly at about 10 times the tree height and
is negligible beyond 20 times the tree height
Equidistant horizontal projection
The equidistant horizontal projection (also known as the horizontal polar projection) plots the
path of the sun at various times of the year on a circular chart
gnomonic projection
gnomonic projection (also called a sunpeg chart) is derived from a sundial projection. It is useful
for shadow studies. A gnomonic projection is used by placing the chart next to the building
model to be studied, then placing a small peg perpendicular to the chart in the location shown.
, The model and chart are tilted in sunlight until the tip of the shadow cast by the peg intersects the
selected date and time.
Rectilinear projection
In a rectilinear projection, the solar azimuth is plotted along the horizontal axis, and the solar
altitude is found along the vertical axis
phase change materials
Phase change materials are used to avoid the overheating and wide swings in temperatures that
can occur with concrete, masonry, and water. Eutectic salts that change from a solid to a liquid at
a fairly low temperature, around 70°F, are commonly used phase change materials. They store
large amounts of heat because they also store latent heat as they undergo the phase change from
solid to liquid. At night, the heat is released as they again change state, from liquid back to solid.
Active solar system
A typical active solar system requires three components: a collector, a storage device, and a
distribution system.
Geothermal energy
Geothermal energy uses ground-source heat pumps (GSHPs). GSHPs are electrically powered
systems that work like air-source heat pumps by either extracting heat from the ground in winter
or giving off excess heat to the ground in summer. Within a GSHP, the heat from the ground is
increased through a vapor-compressor refrigeration cycle.
Main feature of a GSHP
