Straight Run of Rectangular Trunk Line (left); Trunk Duct coming out of Mechanical Room in Airport construction (right) In commercial buildings, whether it be a school, movie theater, office building, arena or hospital, there is a trunk line in the Ductwork serving as the main artery for airflow originating from the indoor air handling units […]
Rectangular Trunk Duct for HVAC Commercial Buildings Read More »
An HVAC Duct Fabrication Shop makes Rectangular Duct and Fittings that serve as the trunk line on commercial jobs. Each job is unique and requires ductwork that’s custom made to accommodate the engineer’s design and the General Contractor’s completion requirements. The goal of a shop foreman is to have fabrication machines based upon his shop’s
Layout of machines in a Ductwork Shop Read More »
Fiberglass Pipe Insulation insulates copper and black iron piping that helps carry domestic hot and cold water, roof drains, PVC piping in plenums, Polypropylene piping, Chill water piping, etc. The pipe insulation comes in 3-foot sticks, with insulation ranging from 1/2″ to 5″ wall thicknesses. These sticks of insulation are installed over pipes and butted
Fiberglass Pipe Insulation Read More »
When a shop is securing weld pins to Fiberglass Duct Liner, it’s typical that they use pins that have a shorter length than the thickness of the liner. On 1″ Fiberglass Duct Liner, for example, 3/4″ long weld pins are used. This compression resembles the quilted look of buttons on a leather chair. By spotting
What type of Weld Pins to use on ductwork with Elastomeric Duct Liner? Read More »
Duct Access Doors are placed in the ductwork, often in the sidewall for easier removal and clearer line of sight, to give access inside the duct. This access is most essential during the inspection process when ensuring that the fire dampers are functional; in fact many Air Distribution plans refer to these as “Access Doors
The Duro Dyne MFPT Compact Pinspotter was staple in duct shops throughout the USA for many decades. For smaller shops, it was their sole means of spotting weld pins to ductwork; for larger shops it was used on all lined fittings and the FG-1 Bulk Feed pinspotter was used on Straight Duct. The fact that
Duro Dyne MFPT vs MF70 Compact Pinspotters Read More »
In HVAC Ductwork, Pressure and Velocity are two standards around which Engineers design duct plans. Building duct to a Higher Pressure class however doesn’t improve the system’s performance in handling vibrations that accompany changes in Velocity. In Duct Fabrication, the familiar criteria on the checklist towards reaching an excellent Pressure Class performance include Duct Gauge
Flexible Duct Connectors control Vibration in Ductwork Read More »
Is Painting Duct Wrap to Match the Ceiling a Thing of the Past? It’s commonly known that fiberglass duct wrap insulation comes standard with an FSK aluminum foil jacket. In fact, over 95% of commercial installations using duct wrap have an FSK jacket. As building design trends shift toward leaving ceilings exposed, this has created an
Fabric Duct has been around for over 30 years but has seen an surge in popularity over the last several years with increased awareness of its existence and its advantages over round metal duct on specific types of indoor low to medium pressure duct systems that have a relatively clean environment. Most common applications for
Square Framed Access Doors are most commonly the Dovetail Tabbed type with a Cam on either side or a Cam and Hinge on either side. They are often included in the Air Distribution package, included as a Lump sum amount. Increasingly, Mechanical contractors study every portion of the Job Site Processes in an effort to
Square Framed Access Doors: Dovetail Tabbed vs Press On Self Stick Read More »
The correct way to Order a Square Elbow: In fabrication of Square Elbows, there are four pieces: two Cheeks (which will end up being the sides of the elbow), one Throat, and one Heel. In the fabrication process everything starts with the Cheek. The first dimension of an Elbow is always the Cheek size; the
Rectangular Duct is hung with 1″ wide 22 gauge (or 20, or 18 gauge) Galvanized Strips that is supplied to the field along with the fabricated ductwork. 10 ft strips, cut and bundled, is the most common. (Some shops use 100 lb coils though any savings in “drop” are negated by the much higher cost of the
Hanging Rectangular Duct with 1″ wide Hanger Strap Read More »
The opening rolls are heat treated when manufactured so that they are not too hard (otherwise they would chip) and not too soft (otherwise they would easily wear out). Without it the pocket closes like this… And the male Pitts doesn’t seat easily… When you know that it’s time to replace the Opening Roll wheel
Opening Roll—Why it’s important Read More »
About 80% of projects that Conklin’s Plan & Spec Division bids have Linear Slot Diffusers (aka LSD’s) on them to some degree. Next time you’re in a relatively new or renovated Airport Terminal, Convention Center, Office Building or (sometimes) your neighborhood’s new Starbucks there’s a good chance you’ll see, in the ceiling, two or three parallel
Linear Slot Diffusers in the Air Distribution Package Read More »
You’ll often hear duct shops refer to “Small Pittsburgh” and “Large Pittsburgh” when they reference their fabrication processes. A duct shop may say for example, “we run Large Pitts on straight duct and Small Pittsburgh on fittings” yet, nowhere will you see this differentiation in SMACNA or by Engineers (in Job Specs). That’s because there’s
Pittsburgh Seam: Small vs Large Read More »
Now that Duro Dyne has redesigned the CCD110 and it looks just like a smaller version of the MF12, what are the differences? After all, they are used the same exact way and have the same (16 gauge) capacity. While Both machines are Single Phase electrics, the CCD-110 runs off 110 Volt (which means it
Duro Dyne Portable and Compact Pinspotters: MF12A vs CCD110 Read More »
Fastening ductwork like square to rounds and flex connections into an assembled fitting can be done with Drill Screws, Pop Rivets, an Acme Lock, a Spotwelder…or a Clinching Machine. While a spotweld’s burn marks don’t make for an aesthetically pleasing product, the products made in a duct shop typically don’t require it. One reality many shops are facing
Norlok Clinching Machines Read More »
The Trumpf F301 Seamcloser is an alternative to an Air Hammer in closing the Pittsburgh Seam into a Lock by means of rollforming it over instead of hammering it over. There are advantages to Closing the Pittsburgh by a Rollforming process rather than a Knocking Over process—a much quieter process and a cleaner looking Lockseam
Trumpf F301 and F300 Pittsburgh Seamcloser Read More »
HETOs in HVAC ductwork: In commercial jobs—whether they be hospitals, office buildings, schools, theatres, arenas or airports—there is a main Trunk line (also called the Loop Duct) that extends throughout the Duct design. It’s rectangular instead of round because it’s sized larger than the downstream duct coming off of it. Rectangular is more practical than round as it
HETOs — High Efficiency Takeoffs Read More »
Rectangular Ductwork is typically insulated internally with Duct Liner rather than externally with Duct Wrap because of the acoustical benefits. Most duct shops will have two pinspotters for use in securing the Duct Liner to the Metal ductwork: a free standing “FG” model with a 5 ft throat and a smaller “MF” model with a 12
FPP5 Bulk Feed Conversion Platform for Pinspotters Read More »
What is the difference between Hi-Temp Silicone “Red” and Firestop? Regular Silicone has a service temperature of -40 to 400F (multi-colors) (Boss 315 is an example). Hi Temp Silicone has a service temperature of -40 to 500F (red) (Boss 376 is an example). FireStop Silicone has a service temperature of -40 to 500F (red) (Boss
What is the difference between Hi-Temp Silicone “Red” and Firestop? Read More »
Roof Curb manufacturers use a lot of 1″ Duct Liner. They also use a lot of adhesive to adhere the liner to the metal and then a much higher than normal % of weld pins to secure the liner to the metal. Why so many weld pins? After all, In a typical HVAC Duct shop the usage
Every Curb Adapter Shop Has Duro Dyne PBF Pinspotters Read More »
There is no excerpt because this is a protected post.
Protected: Flexible Duct Connector Read More »
What The Air Distribution Package is… Rectangular Duct on commercial jobs is also referred to as “Trunk Duct” or the “Loop Duct”. It’s typically where the volume of air is higher. When it begins branching off into various areas of the job, there’s a drop in the amount of air as the system disperses air along
Everything Coming Off of the Rectangular Duct Trunk Lines: The Air Distribution Package Read More »
Because of the name, there’s confusion between these two machines. While each machine turns a flange on the edge of metal, one works only on a flat piece of metal while the other works only on an already formed round pipe edge. Therefore when it comes to their function in a sheet metal shop, these
Power Flanger vs. Power Rotary Machine Read More »
