HVAC PLENUM BOX

412.844.4535

Specifications

Standard Plenum Configurations & Pricing

Side A Side B Side C Side D Material Gauge Price Order
16"x16"20"x20"8"Galvanized26 ga$68.40
18"x18"24"x22"9"Galvanized26 ga$79.20
21"x20"28"x24"10"Galvanized26 ga$92.00
21"x20"32"x26"10"Galvanized24 ga$121.20
24"x22"32"x28"12"Galvanized24 ga$143.76
24"x22"36"x30"12"Galvanized22 ga$194.40

Custom HVAC Plenum Boxes — Supply & Return Air Distribution

A plenum box is the central distribution point in an HVAC system. It attaches directly to the furnace or air handler and distributes conditioned air to branch duct runs (supply plenum) or collects return air from multiple ducts back to the unit (return plenum). Our plenum boxes are custom-fabricated with 4 independently sized and connected sides, allowing precise matching to any trunk line layout.

Supply Plenums

Supply plenums mount to the furnace discharge and distribute heated or cooled air to the trunk lines. Proper sizing ensures even air distribution across all branches. Our plenums support TDC and flanged connections for high-pressure commercial systems, or slip and drive connections for residential installations.

Return Plenums

Return plenums collect air from multiple return ducts and funnel it back to the furnace or air handler intake. Sizing the return plenum correctly prevents restriction that reduces system efficiency and increases blower noise. Each side can have a different connection type to match your existing ductwork.

Custom Sizing

Unlike off-the-shelf plenums, ours are fabricated to your exact dimensions. Each of the 4 sides (A, B, C, D) is independently sized with its own connection type. This means no field modifications, no adapters, and a perfect fit every time.

Frequently Asked Questions

What is a plenum box used for?

A plenum box distributes or collects air from the HVAC system. Supply plenums attach to the furnace output and distribute conditioned air to branch ducts. Return plenums collect air from return ducts back to the furnace.

Can each side of the plenum be a different size?

Yes. Our plenum boxes have 4 independently sized sides (A, B, C, D), each with its own connection type. This allows custom configurations for any trunk line layout.