Email: sales_1@tongbeiltd.com, sales_2@tongbeiltd.com Website: www.tongbeiltd.com | WhatsApp / Mobile: +86 180 1489 5994, +86 186 1603 3978

Spiral Air Duct & Modular Building Solutions

Suzhou Tongbei Technology Co., Ltd. supplies spiral air duct and complete HVAC ductwork systems complying with DW/144 and DW/143 standards, plus prefabricated modular buildings for global B2B clients. From high-quality ductwork to modular housing, we provide one-stop sourcing, custom design, export documentation and reliable after-sales support.

Spiral Air Duct & HVAC Ductwork

Suzhou Tongbei Technology focuses on spiral air duct and complete HVAC ductwork solutions for construction, industrial ventilation, mining camps and temporary site projects worldwide. Our ductwork follows BESA DW/144 fabrication specification and DW/143 air leakage test standard, with complete accessories to meet all ventilation layout requirements.

Spiral duct system installed in a modern building

Spiral Air Duct System

High-performance spiral air duct system for ventilation, air conditioning, exhaust and dust removal. Widely used in factories, commercial buildings, clean rooms and industrial projects. Our spiral duct system is manufactured in accordance with BESA DW/144 specification for sheet metal ductwork, covering material selection, fabrication, joint sealing and pressure classification. Air tightness performance can be tested and verified per DW/143 leakage standard. Tongbei supplies a full portfolio of duct accessories including straight duct, elbows, reducers, tees, insulated components, volume control dampers, non-return dampers, silencers and duct clamps to complete your air system.

  • Galvanized steel or stainless steel material options
  • Custom diameters, wall thickness and cutting length available
  • Complete range of duct fittings: straight, elbow, reducer, tee, insulated parts
  • Volume control dampers & non-return dampers for precise airflow regulation and backdraft prevention
  • Duct silencers to reduce fan and airflow noise for comfortable indoor environments
  • Duct clamps & couplings for secure, airtight duct connections
  • Compliant with BESA DW/144 fabrication standard; air leakage tested to DW/143
  • Strict dimension & leakage inspection before shipment
  • Products manufactured to meet international overseas project standards

Product Variations

Standard Spiral Duct

Standard Spiral Duct

Basic galvanized spiral air duct for ventilation, exhaust and air conditioning systems.

Duct Elbow

Duct Elbow

90° / 45° spiral duct elbow fitting for changing airflow direction in duct systems.

Duct Reducer / Coupling

Duct Reducer

Concentric / eccentric reducer for transition between different duct diameters.

Duct Tee

Duct Tee

T-shaped branch fitting, used to split or combine airflow inside ventilation network.

Insulated Straight Duct

Insulated Straight Duct

Straight spiral duct wrapped with thermal insulation layer, anti-condensation & energy saving.

Insulated Elbow

Insulated Elbow

Insulated duct elbow for bent sections, keeps temperature stable and prevents condensation.

Volume Control Damper

Volume Control Damper

Circular / rectangular air volume regulating valve for precise airflow control in duct systems.

Non-return Damper

Non-return Damper

Backdraft check damper that prevents reverse airflow in ventilation and exhaust ducts.

Duct Silencer

Duct Silencer

Cylindrical sound attenuator that reduces fan and airflow noise in HVAC systems.

Duct Clamp

Duct Clamp

Galvanized steel band clamp with tightening screw, used to secure spiral duct connections.

Square Duct

Square Duct

Rectangular galvanized steel air duct with flanged ends for square duct systems.

Square Elbow

Square Elbow

Rectangular 90° duct elbow fitting for changing airflow direction in square duct systems.

Get Spiral Duct Quote
Modular Building

Modular Building

Prefabricated modular building units for site offices, worker dormitories, temporary accommodation, clinics and site facilities. Fast installation and reusable for different project sites.

  • Quick assembly on site within days
  • Fireproof & thermal insulation panel options
  • Custom layout, doors, windows and interior design
  • Cost-effective for temporary & semi-permanent projects
Get Modular Building Quote

Your Trusted Export Partner

We focus on spiral duct and HVAC ductwork, and combine complementary building products under Suzhou Tongbei Technology to simplify your global project procurement.

One Point of Contact

All inquiries, quotations, order coordination and after-sales handled by Tongbei’s export team.

DW/144 & DW/143

Ductwork fabricated to BESA DW/144 specification with air leakage verified per DW/143 standard.

Full Export Support

We prepare packing list, commercial invoice, and all documents required for sea freight export.

Project Coordination

We support combined orders for both ductwork and modular building for your integrated construction projects.

Single-layer and Rockwool-insulated Spiral Duct
Modular Building

Suzhou Tongbei Technology Co., Ltd.

We are a professional supplier dedicated to the overseas market, based in Suzhou, China, specializing in supplying high-quality products that fully comply with international standards. Our core product portfolio centers on complete spiral air duct and HVAC ductwork systems with full accessories, and also covers prefabricated modular buildings. Our spiral air duct series can be manufactured to meet BESA DW/144 sheet metal ductwork specification, and air tightness can be tested in accordance with DW/143 air leakage standard, widely accepted for UK, Singapore and many international construction projects.

With rich experience serving global engineering and construction clients, we focus on one-stop procurement service for overseas projects. Whether your project requires ventilation duct systems complying with DW/144 & DW/143, or modular accommodation units, we can provide tailored product solutions according to your technical parameters and local code requirements.

We implement strict quality control before shipment for all goods. Our export team handles all logistics and documentation work, including commercial invoices, packing lists, and other customs clearance files. We support mixed container shipments combining spiral duct products and modular building components, helping buyers consolidate orders and save procurement & shipping costs.

Our mission is to become your reliable long-term Chinese supplier. We respond quickly to inquiries, provide clear technical data sheets, and offer consistent after-sales support for all exported products.

Contact Our Team

Send Your Inquiry

Please tell us your required product, specifications, quantity and project details. Our Tongbei team will reply promptly.

Company Information

Suzhou Tongbei Technology Co., Ltd.

  • Website www.tongbeiltd.com
  • Email sales_1@tongbeiltd.com, sales_2@tongbeiltd.com
  • WhatsApp / Mobile +86 180 1489 5994
    +86 186 1603 3978
  • Address Suzhou, Jiangsu, China