Ductwork - In-Wall Duct Systems

In-Wall Duct Systems

Product availability is subject to change without notice. Not all products are available from all facilities.

Rectangular Stack (Riser)

Rectangular Stack Duct

Master Flow's Rectangular Stack Duct is used for HVAC system applications between wall studs as supply and return ducts, and to vent range hoods, kitchen and bath fans between walls as well. Installing rectangular duct between wall studs saves space, and is an easy way to route air up or down a wall and to other stories of a home. It also works in overhead spaces between floor joists or in attics.

  • Sections easily snap together with no tools necessary
  • Can be cut to needed length with simple tin snips
  • Notched corners for easily connecting sections, or use cleats
  • Always seal seams with code-approved mastic, sealant or duct tape



Rectangular Stack Elbows

Rectangular Stack Elbow

The short-way 90-Degree Rectangular Elbow helps create right angle turns in rectangular stack duct runs. This elbow is made of zinc-coated, 30-gauge galvanized steel. You can install this elbow with sheet metal screws.

  • Made of zinc-coated 30 gauge galvanized steel
  • Helps create a right angle turn in rectangular stack duct runs
  • Install with sheet metal screws



Rectangular Stack Heads

Stack Head

The Stack Head helps transition from a rectangular stack duct to a sidewall air register or grill. Designed for durability this stack head is made of zinc-coated, 30-gauge galvanized steel.

  • Made of zinc-coated 30 gauge galvanized steel
  • Designed to move air from rectangular stack duct to a sidewall air register or grill
  • Install with sheet metal screws



Stack Boots Straight

Stack Boot - Straight

The Stack Boot is ideal for creating a straight-line transition between round pipe or flexible duct and stack duct. The stack boot is made of galvanized steel and installs with sheet-metal screws.

  • Galvanized-steel construction
  • Use to create a stright-line transition between round pipe or between an insulated flexible duct and a regular stack duct.
  • Install with sheet metal screws



Stack Boots 90 Degrees

Stack Boot - 90 Degree

The Stack Boot is ideal for creating a 90 Degree transition between round pipe or flexible duct and stack duct. The stack boot is made of galvanized steel and installs with sheet-metal screws.

  • Galvanized-steel construction
  • Use to create a stright-line transition between round pipe or between an insulated flexible duct and a regular stack duct.
  • Install with sheet metal screws



Rectangular Stack Duct Caps

Stack Duct Cap

Rectangular Stack Duct Caps simply cap off a rectangular stack duct run. They are primarily designed to terminate or block off a rectangular duct run in HVAC systems. The duct caps are compatible with most HVAC systems and can be easily installed with sheet metal screws.

  • Sturdy galvanized steel construction
  • Use to cap off rectangluar direct run
  • Install with sheet metal screws
  • Fits most HVAC types for universal application



Rectangular Stack Duct Starting Collars

Stack Collar

The Stack Duct Starting Collar is made of durable, galvanized steel. It is used to transition from a flat surface to stack duct. It installs easily with sheet meat screws.

  • Galvanized-steel construction
  • Use to transition from a flat surface to stack duct
  • Install with sheet metal screws



Fan Boots

Range Hood Fan Boot

Known as a Fan Boot or Range Hood Boot, this product starts the duct run on a vented range hood. It transitions from the 3.25 in. x 10 in. damper (normally included with the Range Hood) to a 7 in. Round Pipe.

  • Galvanized-steel construction
  • 7 in. collar crimped in the direction of airflow out of the unit
  • 3.25 in. x 10 in. opening will fit over the damper normally included with range hood
  • Attach to pipe, elbow, etc as needed



Oval Pipe

Oval Pipe

Oval pipe is used between walls to make duct runs. Can be used for new or retrofit jobs.

  • Galvanized-steel construction
  • Used between walls to make duct runs



Oval 90 Degree Vertical Elbows

Oval Vertical Elbow

The Master Flow 90-Degree Oval Vertical Elbow is designed to change the vertical direction of a run of oval pipe in an HVAC system. It serves as an energy-efficient alternative to a stack duct. This elbow is made of 30-gauge, galvanized steel for strength and durability. It can be installed with sheet-metal screws.

  • 30-gauge, galvanized steel construction for strength and durability
  • Used to change the vertical direction of a run of oval pipe in an HVAC system
  • Energy-efficient alternatives to stack (riser) duct
  • Use sheet-metal screws for a proper installation



90 Degree Flat Elbow

Oval Flat Elbow

The Master Flow 90-Degree Oval Flat Elbow is designed to change the horizontal direction of a run of oval pipe in an HVAC system. It serves as an energy-efficient alternative to a stack duct. This elbow is made of 30-gauge, galvanized steel for strength and durability. It can be installed with sheet-metal screws.

  • 30-gauge, galvanized steel construction for strength and durability
  • Used to change the vertical direction of a run of oval pipe in an HVAC system
  • Energy-efficient alternatives to stack (riser) duct
  • Use sheet-metal screws for a proper installation



Oval Stack Heads With Wings

Oval Stack Head

Oval Stack Heads help you transition from a stack duct to a register. It features built-in wings so you can attach it to your wall studs easily. Installs with sheet-metal screws.

  • Creates a transition from a stack duct to a register
  • Installs with sheet-metal screws
  • Allows ducting to fit between wall studs
  • Built-in wings for easy attachment to wall studs



Oval to Round - Straight

Oval to Round Boot

The Oval-to-Round Boot helps provide a straight transition from an oval pipe to a round pipe or insulated, flexible duct. This boot is an energy-efficient alternative to using a stack duct. Designed for durability, it is made of zinc-coated, galvanized steel.

  • Provides a straight "in-line" transition from an oval pipe to a round pipe or insulated flexible duct
  • Energy-efficient alternative to stack riser duct



Oval to Round Boots - 90 Degree

Oval to Round 90 Degree Boot

The Oval-to-Round Boot helps transition an oval pipe to a round pipe or an insulated flexible duct. It installs with sheet-metal screws.

  • Used to providea right-angle transition from oval pipe to round pipe or insulated flexible duct
  • Installs with sheet-metal screws



Oval to Round - End

Oval to Round to End Boot

The Oval to Round End Boot provides a transition from round pipe or flexible duct to oval pipe. It is energy efficient and installs with sheet-metal screws.

  • Used to provide a right-angle, centered-end transition from round pipe or flexible duct to oval pipe
  • Installs with sheet-metal screws


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