Description
EZ Plenum EZTL21KD Large Triangle Air Distribution Box (Knocked-Down)
The EZ Plenum EZTL21KD is a large triangle air distribution box, often called a tri-box. A supply trunk or flex run feeds the box, and branch ducts take off from its faces to serve several rooms or registers from one point. It is made from R-6 fiberglass duct board.
This is the knocked-down version, shipped flat for builders and distributors who would rather save warehouse space and fold the box together on site.
Key features
R-6 fiberglass construction. Insulated duct board walls keep air at temperature and stop condensation on the box.
Triangle (tri-box) shape. The three-sided layout lets you run branch takeoffs off each face from one central box.
Ships knocked-down. Panels ship flat to save space and fold into the finished box on site.
Clear sizing. 21 inch sides outside, 18 inch sides inside and 23 inches tall.
Checking the fit
Outside, each side measures 21 inches; inside, each side is 18 inches. The box stands about 23 inches tall once assembled. Make sure the space above the ceiling or in the attic allows for that footprint and height plus your duct connections.
Frequently asked questions
What is a triangle air distribution box used for? It splits one supply into several branch runs, a common layout in attic and ceiling duct systems.
Is it insulated? Yes, the walls are R-6 fiberglass duct board.
Are duct collars included? No. Cut in the takeoffs or collars your layout needs.
