Perry Fiberglass Products Inc.
- Manufacturer of fiberglass reinforced plastic duct systems for corrosive environments, pools, natatoriums, wwtp, chemical underground hvac.
- http://www.perryfiberglass.com/

Eco Products, Inc.
- Commercial HVAC ductwork and accessories.
- http://www.ecoduct.com/

Pal International S.r.l.
- Manufacture foam based pre-insulated ductwork . Product specifications, and completed installations .
- http://www.koolduct.com/

Fabri-Tech, Inc
- Custom steel fabrication specialists. Carbon and stainless ductwork, chutes, hoppers, bins, launders, tanks, breeching, and plate work.
- http://fabtechnology.com/

USF Fabrication
- Fabricate and supply access doors and hatches.
- http://www.usffab.com/

Nystrom Building Products
- Manufacture access panels, floor and roof hatches, louvers and expansion joint systems. Includes downloadable CAD drawings and CSI specifications.
- http://www.nystrom.com/

Truduct Products Limited
- Stockists of ductwork and associated products. United Kingdom.
- http://www.truduct.co.uk/