Spiral Manufacturing Co., Inc. - Minneapolis, MN
Manufacturer, Custom Manufacturer
Custom manufacturer of PVS coated galvanized steel underground ducts. PVC or PVS coated underground ducts are available in 4 in. to 50 in. PVC coated underground ducts are suitable & ideal for HVAC as well as corrosive fume exhaust applications. UL listed. Pipe and fittings available from stock.
www.spiralmfg.com/recducf.htm

Marstan, Inc. - Minneapolis, MN
Manufacturer
Wholesale manufacturer of low pressure HVAC products including galvanized & polyvinyl coated elbows, reducers, tees, saddles, laterals, couplings & pipe. Available in PVS, galvanized, stainless steel, PaintGrip & aluminum.
www.marstaninc.com/index.html

Monoxivent - Rock Island, IL
Manufacturer
Manufacturer of underground exhaust systems including HVAC & fiberglass ducts for swimming pool, hospital, high rise office, restaurants & auditorium applications. Products are available as single wall & pre-insulated double wall duct to meet many ventilation needs. Duct products are also approved for direct burial. Capabilities include custom design & installation with accessories such as fittings & joints.
www.underduct.com

UnderDuct - Rock Island, IL
Distributor, Manufacturer
Manufacturer of fiberglass reinforced plastic (FRP) ducts for underground & underfloor applications. Ducts are available in various configurations, colors & shapes including round, rectangular, oval & triangular with 2 in. to 144 in. dia. & 1/8 in. to 1 in. wall thickness. Ducts feature resin veil finish, corrosion & leakage resistance, single wall & pre-insulated double wall designs & internal galvanized sheet metal sleeve joints. Fitting options include square-to-round, crosses, flanges, elbows, tees, reducers & dampers. Industries served include auditorium, auto exhaust, bank, botanical garden, church, hospital, high rise office, parking garage, residence, restaurant, school, super market, swimming pool & zoo. Meets ASTM, NBS PS 15-69, SMACNA & UMC 10-1 standards. UL listed.
www.underduct.com/configurations.php

Colonial Teltek - King of Prussia, PA
Distributor
Distributor of flexible ducts. Types of ducts include direct burial telecom conduits, PVC rigid nonmetallic conduits, direct burial rigid PVC utility ducts, encased burial rigid PVC utility ducts and high density polyethylene (HDPE) ducts.
www.colonialelectric.com/pdf/teltek-catalog...

Atlantic Air Products Manufacturing LLC - Bow, NH
Manufacturer
Manufacturer of HVAC equipment including sheet metal & spiral accessories for industrial applications. Take-off collars, louvers, elbows, round pipe, plenums, transitions, roof curbs, duct dampers & spiral ducts are also available.

Composites USA - North East, MD
Manufacturer, Custom Manufacturer, Service Company
Custom manufacturer of underfloor & underground ducts including fiberglass reinforced plastic (FRP) ducts. Fiberglass reinforced plastic ducts can be used for corrosive fume exhaust from process areas, fresh air supply & light weight conveying of liquids & solids. Ducts are UL® listed & FM approved. Meets MIL-I-45208-A specifications.

MI-Kee-Tro Metal Manufacturing, Inc. - York, PA
Manufacturer, Custom Manufacturer, Service Company
Custom manufacturer of ducts including underfloor & underground ducts. Shapes include flat, round & spiral with fittings. Features include T.D.C., slip & drive & snap lock connections. Available in materials including aluminum, stainless steel, galvanized, galvaneal & carbon steel. Cable hanging systems, access doors & spiral connecting systems also available. Applications include roof curbs, equipment rails, hoods & guards.

CDC Enterprises, Inc. - Zimmerman, MN
Manufacturer
Manufacturer & developer of patented HDPE (high density polyethylene) based HVAC duct delivery systems. Includes PVC, plastic piping, & polyethylene underground HVAC systems in up to 3 ft. below water. Above ground systems use polyethylene HVAC ducts which comply with UL-181/ICC approval. Serves residential, commercial, & institutional markets.
Brand Names: AKDUCT, QADUCT