NATE AIR DISTRIBUTION STUDY GUIDE
Duct - answers- a pathway that carries air between two points
Duct system - answers- an arrangement of ducts between the heating and cooling
equipment and the rooms to be conditioned
Flexible duct - answers- often is used in attic installations, and in other areas where
there is likely to be a temperature difference of greater than 15 degrees fahrenheit
between the conditioned air inside the duct and the ambient air immediately outside the
duct
Ductboard (rigid fiberglass duct) - answers- is available in either round, prefabricated
lengths, or in flat sheets
Constructing and installing a ductboard system requires - answers- specialized tools for
creating overlapping joints
When two pieces of ductboard are joined - answers- they are stapled together and
taped
Sheet metal duct - answers- is frequently used in residences that have basements or
crawlspaces, since these types of structures have the physical space needed for
mounting the duct underneath floor joists
A reducing duct system - answers- maintains pressure from start to finish be reducing
the size of the trunk duct as branch ducts are connected
In an extended plenum duct system - answers- the trunk duct does not vary in size,
even after branches have been taken off. It remains constant in cross-sectional area.
A box plenum duct system differs from the extended plenum in - answers- the size of
the plenum, which can be quite large comparatively
In a extended plenum duct arrangement, branch ducts leading to the registers are -
answers- not connected directly with the furnace plenum, but are attached to an
extended plenum trunk duct
Air is removed from a room and sent to the unit through the - answers- return intake
opening
One return intake may serve - answers- more than one room, such as in a hallway
The most important feature of the return grille is - answers- that the opening must be
ample in size so that the air flow is not restricted
, The return grille is fitted into a metal box called a - answers- stack head
Stacks in residential services are usually - answers- 30-gauge sheet metal
A wall stack is - answers- a rectangular duct that runs vertically in the studding space of
a frame wall
The standard widths of stacks are - answers- 8, 10, 12, and 14 inches
On the return side of a cooling system, the stack and stack head are - answers-
frequently omitted. Instead, studding space is used as a duct passageway.
In an actual duct system design, - answers- the ducts are often slightly oversized.
Dampers are used for the final balancing of the system.
A duct system that is easily balanced will show a - answers- minimum increase in
pressure loss after balancing is complete
A perimeter loop duct arrangement - answers- addresses the problem of cold floors in
winter in a house built on a concrete slab
The registers in a perimeter radial duct arrangement are - answers- fed directly from
ducts connected to the subfloor plenum
The boot is - answers- a connection or fitting that joins the stack to the horizontal duct
at the lower level
Return duct - answers- is a return passage for air
All of the return ducts meet at a common chamber called - answers- the return plenum
The blower is typically a - answers- centrifugal or "squirrel-cage" type fan
A furnace - answers- burns fuel, such as natural gas or oil, within a heat exchanger
Casing is - answers- an insulated rectangular sheet metal enclosure around a heat
exchanger or coil
The evaporator offers substantial resistance to - answers- the flow of air
A supply plenum is - answers- a large box to which ducts are attached
A well designed supply plenum will mix the air so that it is not - answers- stratified into
cold and hot layers
Conditioned air leaves the supply plenum through a large - answers- trunk duct
Duct - answers- a pathway that carries air between two points
Duct system - answers- an arrangement of ducts between the heating and cooling
equipment and the rooms to be conditioned
Flexible duct - answers- often is used in attic installations, and in other areas where
there is likely to be a temperature difference of greater than 15 degrees fahrenheit
between the conditioned air inside the duct and the ambient air immediately outside the
duct
Ductboard (rigid fiberglass duct) - answers- is available in either round, prefabricated
lengths, or in flat sheets
Constructing and installing a ductboard system requires - answers- specialized tools for
creating overlapping joints
When two pieces of ductboard are joined - answers- they are stapled together and
taped
Sheet metal duct - answers- is frequently used in residences that have basements or
crawlspaces, since these types of structures have the physical space needed for
mounting the duct underneath floor joists
A reducing duct system - answers- maintains pressure from start to finish be reducing
the size of the trunk duct as branch ducts are connected
In an extended plenum duct system - answers- the trunk duct does not vary in size,
even after branches have been taken off. It remains constant in cross-sectional area.
A box plenum duct system differs from the extended plenum in - answers- the size of
the plenum, which can be quite large comparatively
In a extended plenum duct arrangement, branch ducts leading to the registers are -
answers- not connected directly with the furnace plenum, but are attached to an
extended plenum trunk duct
Air is removed from a room and sent to the unit through the - answers- return intake
opening
One return intake may serve - answers- more than one room, such as in a hallway
The most important feature of the return grille is - answers- that the opening must be
ample in size so that the air flow is not restricted
, The return grille is fitted into a metal box called a - answers- stack head
Stacks in residential services are usually - answers- 30-gauge sheet metal
A wall stack is - answers- a rectangular duct that runs vertically in the studding space of
a frame wall
The standard widths of stacks are - answers- 8, 10, 12, and 14 inches
On the return side of a cooling system, the stack and stack head are - answers-
frequently omitted. Instead, studding space is used as a duct passageway.
In an actual duct system design, - answers- the ducts are often slightly oversized.
Dampers are used for the final balancing of the system.
A duct system that is easily balanced will show a - answers- minimum increase in
pressure loss after balancing is complete
A perimeter loop duct arrangement - answers- addresses the problem of cold floors in
winter in a house built on a concrete slab
The registers in a perimeter radial duct arrangement are - answers- fed directly from
ducts connected to the subfloor plenum
The boot is - answers- a connection or fitting that joins the stack to the horizontal duct
at the lower level
Return duct - answers- is a return passage for air
All of the return ducts meet at a common chamber called - answers- the return plenum
The blower is typically a - answers- centrifugal or "squirrel-cage" type fan
A furnace - answers- burns fuel, such as natural gas or oil, within a heat exchanger
Casing is - answers- an insulated rectangular sheet metal enclosure around a heat
exchanger or coil
The evaporator offers substantial resistance to - answers- the flow of air
A supply plenum is - answers- a large box to which ducts are attached
A well designed supply plenum will mix the air so that it is not - answers- stratified into
cold and hot layers
Conditioned air leaves the supply plenum through a large - answers- trunk duct
