HstubeHVAC

Plenums & Air Boxes

Galvanised steel plenum boxes and return air boxes for duct-to-diffuser transitions. Available in dozens of size configurations for residential and commercial HVAC.

Galvanised steel bodyMultiple neck sizesTop / Side / Rear entryStandard & custom configsFilter-ready return boxes

Available Models (5)

Supply Air Plenum

Supply Air Plenum

Supply Air Plenum in Galvanised Steel finish. Available in 10 sizes from 1060×180 2×14 to 925×255 3×14. Custom sizes available.

FinishGalvanised Steel
SKU Count10
Size Range1060×180 2×14 — 925×255 3×14
DetailsGet a Quote
Supply Air Plenum

Supply Air Plenum

Supply Air Plenum in Galvanised Steel finish. Available in 8 sizes from 1070×300 2×14 to 900×350 3×14. Custom sizes available.

FinishGalvanised Steel
SKU Count8
Size Range1070×300 2×14 — 900×350 3×14
DetailsGet a Quote
Supply Air Plenum

Supply Air Plenum

Supply Air Plenum in Galvanised Steel finish. Available in 4 sizes from 1030×270 2×14 to 1030×340 3×14. Custom sizes available.

FinishGalvanised Steel
SKU Count4
Size Range1030×270 2×14 — 1030×340 3×14
DetailsGet a Quote
Supply Air Plenum

Supply Air Plenum

Supply Air Plenum in Galvanised Steel finish. Available in 16 sizes from 1170×220 2×12 to 820×220 3×10. Custom sizes available.

FinishGalvanised Steel
SKU Count16
Size Range1170×220 2×12 — 820×220 3×10
DetailsGet a Quote
Return Air Box

Return Air Box

Return Air Box in Galvanised Steel finish. Available in 72 sizes from RETURN AIR BOX 1000×400 2×14" to RETURN AIR BOX 900×600 2×16". Custom sizes available.

FinishGalvanised Steel
SKU Count72
Size RangeRETURN AIR BOX 1000×400 2×14" — RETURN AIR BOX 900×600 2×16"
DetailsGet a Quote

Need Custom Plenums?

We offer OEM manufacturing, custom dimensions, and private labeling. Share your specs and get a quote within 12 hours.

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Frequently Asked Questions

What is the MOQ for plenums & air boxes?
Minimum order quantities vary by specific model. Standard catalog items typically start at 100–500 pieces. For OEM or custom orders, MOQ is usually 500–2,000 pieces depending on tooling requirements. Contact our sales team for exact MOQ and pricing.
Do you offer OEM/ODM manufacturing for plenums & air boxes?
Yes, we offer full OEM and ODM services including custom dimensions, materials, finishes, and packaging. Our engineering team can work from your drawings or develop custom solutions based on your specifications. We have been an OEM partner for global HVAC brands for over 20 years.
What is the lead time for plenums & air boxes?
Standard catalog items ship within 15–25 business days from our China facility. Custom or OEM orders typically require 30–45 days. Spiral duct products from our Houston, TX factory can ship within 5–10 business days for US customers.
What certifications do your plenums & air boxes have?
Our products carry UL, CE, M1 (France), ROSH, and AWTA (Australia) certifications depending on the product line. Fire dampers are UL 555 listed. All products are manufactured under ISO quality management standards. View our certifications.