Shop Linear Slot Diffuser Plenum Boxes (12"–72")

Browse our full range of linear plenum boxes for 1-slot, 2-slot, 3-slot, and 4-slot diffusers. Available in fiberglass R-6 insulated plenums, knock-down configurations, and multiple entry/collar sizes (single or dual), these boxes are manufactured for efficient air distribution. Compatible with leading diffuser brands, EZ Plenum’s solutions make installation easy and reliable for contractors. Find the perfect 12", 18", 20", 24", 30", 36", 48", 60", or 72" plenum box to fit your HVAC system requirements.

What is a linear plenum box?

A linear diffuser plenum box is an HVAC air distribution box used to distribute air. It connects to your supply air duct by means of flexible duct. Our linear plenum boxes are available both in universal fiberglass or with duct collar options.