Question

It is not a duct system –

• A. Reduced plenum duct system
• B. Radial perimeter duct system
• C. Extended plenum duct system
• D. Loop perimeter duct system

Hint:

Recall the standard duct layouts: extended plenum, reducing plenum, radial perimeter and perimeter loop.

Answer 1

The Correct Option is A

Step 1: Understand what a duct system does:
A duct system carries conditioned air from the air handling unit to the rooms. The layout is chosen to suit the shape of the building.

Step 2: Recall the common layouts:
The extended plenum system uses a large main duct, with branches taken off along its length.
The radial perimeter system has ducts running out from a central plenum to outlets near the outer walls.
The perimeter loop system has a ring of duct round the building with outlets along the outer walls.
The reducing plenum system has a main duct whose size is reduced in steps as branches leave.

Step 3: Compare with the options:
Radial perimeter, extended plenum and perimeter loop (loop perimeter) are all standard duct systems.
The standard name of the fourth system is the reducing plenum system, and the option reads "reduced plenum", which is not the name used for a duct system.
So the option that is not a standard duct system name is option (A).

Final Answer:
Option (A), Reduced plenum duct system. The standard duct system is the reducing plenum system.