Industries · 4 min read ·
HVAC and ductwork fabrication: shop workflow and machines
How HVAC sheet metal shops turn galvanized steel into duct, fittings and plenums, which machine does each step, and how heat pump retrofits shape demand.
An HVAC sheet metal shop turns thin galvanized steel into straight duct, fittings, plenums and equipment casings for mechanical contractors. The machine core is a CNC plasma table or fiber laser for fitting patterns, a shear for straight blanks and a CNC press brake for plenums and transitions, with seaming and roll-forming equipment alongside.
What HVAC fabrication shops make, and for whom
Duct shops sit between the design engineer and the installer. Their daily output is supply and return trunk, elbows, offsets, transitions, takeoffs and boots, plus custom plenums, roof curbs and access doors. Commercial shops add large rectangular duct, equipment casings, stainless kitchen exhaust hoods and other food service work. Many shops are the fabrication arm of a mechanical contractor; others sell to several contractors and builders.
The Red Seal description of the sheet metal worker trade reflects this mix. The trade covers layout, fabrication, installation and repair, with specializations that include HVAC, architectural sheet metal and food service products, in materials ranging from galvanized and stainless steel to aluminum and copper.
What drives demand in Canada
New residential and commercial construction needs complete duct systems, and that remains the base load. Retrofits are the second driver. Natural Resources Canada notes that heat pumps generally supply a greater volume of air at a lower temperature than furnaces (normally 25 to 45°C, against 55 to 60°C for a furnace) and that existing ductwork may need changes to avoid noise and higher fan energy use. Each retrofit tends to need a few custom transitions or larger trunk sections, which rewards shops that can cut one-off fittings quickly.
The third driver is equipment manufacturing. Statistics Canada data published by ISED counts 798 establishments making ventilation, heating, air-conditioning and commercial refrigeration equipment in 2025, with 380 in Ontario and 180 in Quebec. Their casings, panels and brackets are sheet metal work as well. The Heating, Refrigeration and Air Conditioning Institute of Canada (HRAI), founded in 1968, brings together the manufacturers, wholesalers and contractors along this chain.
Duct shop process flow
- Takeoff and layout. Fittings are taken off the mechanical drawings and developed into flat patterns by duct fitting software, which also nests them on the sheet.
- Straight duct. Coil or sheet is cut to blank size, lock seams and connectors are roll-formed, and the blank is folded into sections. Coil lines, lock formers and roll formers are not in our online catalog; ask about them when you request a quote.
- Fitting blanks. A CNC plasma table is the traditional duct shop cutter. A fiber laser is the option when cleaner edges on thin galvanized and stainless matter more than purchase cost.
- Shearing and bending. A shear produces strips, cleats and straight blanks. A press brake forms plenums, casings, transitions and hood panels.
- Assembly. Seams are closed, parts are fastened or spot welded, then sealed. Stainless hoods and food service work are TIG or laser welded.
- Labelling and delivery. Fittings are marked by job, floor and system so installers can find them on site.
Equipment line-up by shop stage
| Stage | Typical shop | Cutting and shearing | Bending |
|---|---|---|---|
| Starter | Contractor's in-house shop, mostly residential | Plasma table in the 1220 x 2440 mm (4 x 8 ft) class and a compact swing-beam shear such as the Baykal HGL 2606 (2.56 m, 6 mm mild steel) | Manual brakes plus a 110-ton CNC brake such as the Accurl Euro Pro B 32110 (3.2 m, Delem DA58T control) |
| Growing | Independent shop serving several contractors | 1.5 x 3 m (5 x 10 ft) plasma table built around a Hypertherm XPR300 source, such as the Accurl CPL-1530, and a CNC guillotine shear with automatic blade gap such as the Haco TSX 3012 | Second CNC brake so long casings and small fittings run in parallel |
| High volume | Commercial and industrial duct, equipment casings | Enclosed fiber laser with exchange table, coil-fed blanking | Several brakes with offline programming, dedicated seaming and roll-forming cells |
Two choices come up in almost every duct shop plan. Plasma against laser for fittings is covered in our fiber laser vs plasma comparison, and the shear decision in swing-beam vs guillotine shears. For thin galvanized work the deciding factors are the edge quality your seams need, how much stainless you cut and the running cost per sheet.
Planning a duct shop
Space for bulky, light parts
Formed duct is mostly air. Staging and shipping areas usually take more floor than the machines, so plan racks, carts and a loading door for finished fittings, and keep coil and sheet storage at the blanking end of the building.
Fumes and noise
Cutting and welding coated steel produces fumes, so plasma and laser tables need extraction or a water table, and welding stations need local exhaust. Seaming and hammering are loud. The Red Seal trade description lists sharp metal, noise, vibration, heat and fumes among the hazards of the work.
Electrical and air
Budget for a 600 V three-phase supply or transformers, and for clean, dry compressed air for plasma cutting and pneumatic tools. Whether each machine needs a CSA certification or field evaluation is confirmed in the quote.
Skills
Sheet metal worker is a Red Seal trade, and experienced certified workers can still develop an odd fitting by hand when the software cannot. Pair them with one person responsible for the fitting software and CNC programs, since same-day turnaround on one-off fittings depends on that link.
Questions and answers
What machines does an HVAC duct shop need?
A cutting table for fitting patterns (CNC plasma or fiber laser), a shear for straight blanks, a CNC press brake for plenums and transitions, and seaming and roll-forming equipment for straight duct. Fitting software ties the cutting side together.
Is plasma or fiber laser better for duct fittings?
Plasma tables are the traditional, lower-cost choice for galvanized fittings. A fiber laser costs more to buy but gives cleaner edges on thin galvanized and stainless sheet, which matters for seams and visible work.
Do heat pump installations change ductwork requirements?
Often. Natural Resources Canada notes that heat pumps usually supply more air at a lower temperature than furnaces, so existing ducts may need modification to avoid noise and higher fan energy use.
What trade qualification do duct fabricators hold in Canada?
Sheet metal worker is a Red Seal trade covering layout, fabrication, installation and repair, with HVAC as a common specialization. Training and certification are run by the provincial and territorial apprenticeship authorities.
