Expert Sheet Metal Fabrication Services
AMHAC has an in-house sheet metal fabrication ship, which allows for customization of ductwork to exact specifications.This ensures the system is perfectly designed for your home or business making it easier to install, less obtrusive, makes less noise, and provides superior comfort and indoor air quality.
Due to our extremely cold weather conditions this is especially important as the air will circulate through your system up to twelve times per day. AMHAC performs work on-site, takes precise measurements, and fabricates in-house. Utilizing state-of-the-art laser technology, there’s no margin of error.
Custom Ductwork Design & Installation
AMHAC offers high quality ductwork installation, ductwork fabrication, and custom ductwork products for residential & commercial heating and air conditioning systems. Our ductwork solutions are practical, cost effective and custom made to achieve optimal performance of your heating/cooling equipment.
Sheet Metal Fabrication for Hotels & Other Commercial Spaces
AMHAC has been building its resume over 70 years with over 15,000 local homeowners and businesses (including two of the larger hotels in the area) trusting AMHAC for all of their HVAC needs. We design your ductwork to take best advantage of the space, requiring fewer seams, turns, and connections. When you trust AMHAC with your sheet metal fabrication, you can expect top-quality materials, expert workmanship, and quicker turnarounds.
We offer free estimates across Westchester County, NY, Fairfield County, CT, Manhattan and the Bronx.
When Standard Ductwork Simply Does Not Fit
Every home and commercial building presents its own layout, and that reality is where off-the-shelf duct components often fall short. An older house with irregular joist spacing, a retail space with a low ceiling, or a mechanical room packed with equipment all demand custom solutions. This is the point where sheet metal fabrication moves from an abstract idea to a practical necessity. At AMHAC, we build ductwork and metal components to the exact dimensions a project requires, rather than forcing a building to accept parts that were never designed for it.
The difference between a system that performs quietly and efficiently and one that whistles, leaks, or short-cycles frequently comes down to how well the metal was measured, cut, and joined. When ducts are fabricated to match the actual conditions of a space, air moves the way engineers intended. That is why we treat fabrication as a core discipline rather than an afterthought, applying the same reputation of quality, expertise, and innovation we have carried since 1949.
What Sheet Metal Fabrication Involves
Sheet metal fabrication is the process of transforming flat sheets of metal, most often galvanized steel or aluminum, into the ducts, plenums, transitions, and fittings that make up a complete air distribution system. The work begins with measurement and layout, continues through cutting and forming, and finishes with joining and sealing. Each stage builds on the accuracy of the one before it, which is why a small error early in the process can create a much larger problem later.
Galvanized steel remains the most common material for HVAC ductwork because its zinc coating resists corrosion and it holds its shape well under pressure. Aluminum is chosen where weight matters or where corrosion resistance is a higher priority. Gauge selection, meaning the thickness of the metal, is not arbitrary. Larger ducts and higher static pressures call for heavier gauges to prevent the metal from flexing, drumming, or collapsing over time.
Our shop follows a logical progression from raw material to finished component:
- Layout and measurement: We translate field measurements and system requirements into precise patterns that account for seams, flanges, and connection points.
- Cutting and notching: Flat stock is cut to the pattern, with notches added where the metal will fold to form corners.
- Forming and bending: Brakes and rollers shape the flat metal into rectangular ducts, round pipe, or curved transitions.
- Seaming and joining: Edges are locked, riveted, or welded to create rigid, airtight assemblies.
- Sealing and finishing: Joints receive mastic or approved sealant so that conditioned air stays inside the duct where it belongs.
Precision Forming and the Tools Behind It
The forming stage is where flat sheets become three-dimensional components. A press brake bends metal along straight lines to create the sides of a rectangular duct, while rolling equipment produces round pipe and elbows. The angle of each bend has to be accurate to a fraction of a degree, because ductwork sections must mate cleanly with one another. If two sections do not line up, gaps appear, and gaps mean air leakage, energy waste, and noise.
Seams and joints deserve particular attention. A Pittsburgh lock seam, for example, folds two pieces of metal together in an interlocking pattern that adds strength while keeping the joint tight. Drive cleats and S-cleats connect duct sections end to end and allow for slight adjustments during installation. Each of these connection methods has a purpose, and choosing the right one depends on duct size, operating pressure, and where the section will sit within the overall system.
Transitions are among the most demanding pieces to fabricate. A transition connects two ducts of different sizes or shapes, such as a rectangular main trunk narrowing into a smaller branch. If a transition changes size too abruptly, it creates turbulence that increases resistance and reduces airflow. A properly built transition tapers gradually, guiding air smoothly from one section to the next. Building these correctly requires both mathematical layout and hands-on skill, and it is one of the areas where custom fabrication clearly outperforms standard parts.
Where Custom Metal Work Makes the Difference
Custom fabrication solves problems that pre-made components cannot. We regularly encounter situations across Eastchester, Scarsdale, New Rochelle, White Plains, Bronxville, Mamaroneck, Riverdale, Yonkers, NY and Greenwich, CT where a stock fitting would either not fit or would compromise system performance. In these cases, building the part to order is not a luxury but the only way to deliver a system that works as designed.
Some of the most common scenarios where fabricated metal proves its value include:
- Retrofit projects in older buildings: Historic homes and aging commercial structures rarely have the standard cavities modern duct assumes, so custom pieces are shaped to fit around beams, pipes, and existing framing.
- Tight mechanical rooms: When space around a furnace or air handler is limited, custom plenums and offsets route air efficiently without forcing sharp, restrictive turns.
- High-efficiency system upgrades: New equipment often has different connection sizes than what it replaces, and custom transitions bridge that gap cleanly.
- Zoned and multi-branch layouts: Complex distribution systems call for precisely sized branches and dampers so that each zone receives the correct volume of air.
Beyond ductwork, sheet metal fabrication produces plenums that connect equipment to the duct system, custom hoods and vents, drain pans, flashing, and register boots. Each of these components plays a role in a system that must move air quietly, distribute temperature evenly, and operate for years without failure. Because we control the fabrication process, we can respond to unusual requirements without waiting on outside suppliers or settling for a part that is merely close enough.
Technical Standards That Guide Our Work
Quality fabrication is measured against clear technical benchmarks. Duct sizing is determined by the volume of air a system must move, expressed in cubic feet per minute, balanced against the static pressure the equipment can overcome. Undersized ducts starve the system and force the blower to work harder, while oversized ducts waste material and can reduce air velocity below what is needed for proper distribution.
Sealing standards matter just as much as sizing. Even well-built ducts can lose a meaningful percentage of conditioned air through unsealed joints. We seal seams and connections with appropriate mastic and fasteners so that the air your equipment conditions actually reaches the rooms it is meant to serve. Proper support and hanging are equally important, because ducts that sag or vibrate against framing generate noise and can loosen their seams over time. Attention to these details is what separates fabrication that lasts from work that requires repeated service calls.
Our Commitment to the Communities We Serve
At All Makes Heating & Air Conditioning (AMHAC) we dedicate time together towards improving the experience we provide to our clients. Although decisions and actions aren’t always clear-cut, it’s our values that provide us with guidelines for our choices. It is through the company standards that we improve our chances to behave consistently as a team on giving memorable experiences and making our family, friends, neighbors, and suppliers glad to live and work with us.
That commitment carries directly into our fabrication shop. When we build a duct system for a home in Eastchester, Scarsdale, New Rochelle, White Plains, Bronxville, Mamaroneck, Riverdale, Yonkers, NY and Greenwich, CT, we are building something a family will rely on through hot summers and cold winters for many years. We hold ourselves to standards of accuracy and durability because we understand what is at stake. Call AMHAC and experience our mission and values firsthand. We will ensure that servicing and/or replacing your HVAC equipment, including any custom sheet metal fabrication your project requires, will be an outstanding customer experience.
