Plenum Box Manufacturer · 72+ SKUs · UL Certified · Custom OEM
Plenum boxes,built to spec.
Supply plenums, return air boxes, multi-neck distribution plenums, and custom fabrication — from a manufacturer that has shipped 200,000+ units to 60+ countries. UL listed. In-house tooling. R-4.2 and R-6 insulation. From $7/pc FOB.
Four plenum categories, one factory
Supply Plenum Boxes
Single and multi-neck configurations (1, 2, or 3 collars). Standard 595×595 mm and large-format sizes up to 1325×470 mm. Neck sizes 6"–18". Uninsulated, R-4.2, and R-6 insulation options.
$7–32/pcReturn Air Boxes
72 SKUs covering every standard ceiling grid dimension. Integrated filter frames (1" and 2" depth). Removable access panels for maintenance. Galvanized steel construction.
$6–22/pcMulti-Neck Distribution Plenums
2-collar and 3-collar configurations for radial and reducing trunk duct systems. Used as central distribution points in residential and light commercial HVAC.
$12–42/pcCustom Fabrication
Non-standard sizes, special collar positions (side or top entry), motorized damper integration, acoustic lining, fire-rated assemblies. Our engineering team works from your mechanical drawings.
QuoteQuick sizing by system tonnage
| System | CFM | Neck Size | Plenum Size | Price (FOB) |
|---|---|---|---|---|
| 2 Ton | 800 CFM | 8"–10" | 595×595 mm | $7–14 |
| 2.5 Ton | 1,000 CFM | 10"–12" | 595×595 mm | $9–18 |
| 3 Ton | 1,200 CFM | 12"–14" | 595×595 mm | $11–22 |
| 4 Ton | 1,600 CFM | 14"–16" | 595×595 or 595×1195 mm | $14–28 |
| 5 Ton | 2,000 CFM | 16"–18" | 595×1195 mm or dual-neck | $18–36 |
CFM = 400 × Tons of Cooling (ACCA Manual D). Neck velocity ≤ 700 FPM. Prices for standard galvanized uninsulated; add 40-60% for R-4.2, 70-100% for R-6 insulation.Read the full sizing guide →
Technical guides
Plenum Box Catalog
Full product catalog with specs, materials, insulation options, and pricing
Plenum Box Sizing Chart
2-Ton to 5-Ton systems, CFM calculations, installation guide
Supply vs Return Plenum
Construction differences, insulation, filter options
Distribution Plenum Design
Multi-outlet CFM, static pressure, silenced plenums
Sizing Calculator
Step-by-step formulas for CFM, neck, depth, expansion ratio
Ceiling Plenum vs Ducted Return
Cost, noise, efficiency comparison — when to use each system
Plenum box manufacturing — FAQ
What makes Airwise different from other plenum box manufacturers?▾
Three things: (1) We design and build our own production equipment — every stamping die and forming tool is made in-house, giving us the flexibility to produce custom configurations without expensive retooling. (2) We manufacture both the plenum box AND the diffusers, grilles, and ductwork it connects to — so dimensional compatibility is guaranteed. (3) UL listing — one of only 3 Chinese HVAC manufacturers to achieve this certification.
Can you manufacture plenum boxes to match specific HVAC brand specifications?▾
Yes. We regularly produce plenums to match Titus, Price Industries, Krueger, MetalAire, and Nailor specifications. Send us the brand specification sheet or part number, and we will confirm dimensional and performance compatibility. We can also reverse-engineer from a sample unit.
What is the production capacity for plenum boxes?▾
Our Dongyang facility produces 15,000-20,000 plenum boxes per month across all configurations. A typical 40ft HC container holds 400-600 standard 595×595 mm supply plenums. We can ramp production for large projects with 2-3 weeks notice.
Do you provide engineering support for plenum sizing?▾
Yes, free of charge on orders over 100 pieces. Send us your mechanical drawings (PDF or CAD) and we will: (1) confirm plenum sizes per ACCA Manual D guidelines, (2) recommend neck sizes based on CFM requirements, (3) specify insulation requirements, and (4) provide a bill of materials with pricing. Our engineers have sized plenums for projects in 60+ countries.
What insulation options are available?▾
Three options: (1) Uninsulated — galvanized steel only, for return air applications or warm climates. (2) R-4.2 — 25mm fiberglass liner with foil facing, standard for residential supply plenums. (3) R-6 — 38mm fiberglass liner with foil facing, required for commercial systems and cold climates per ASHRAE 90.1. All insulation meets ASTM C1071 and UL 181 requirements.
Need plenum boxes?
Standard catalog or custom fabrication. Send your specifications or mechanical drawings — we quote within 12 hours.