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DW Primark2
DW Primark

We keep a large assortment of 3"- 24" spiral pipe and fittings in stock. Our team will make your 26" - 54" pipe and fittings upon request in hours or days depending on the size of the job. All double wall pipe (perforated or solid core interior)  made to order. All of our spiral pipe is made in our Fairfield, NJ facility. We stock: galvanized, galvanneal, perforated, PCD (paint lock), aluminum, and stainless steel coils. Call or email today for pricing.

 Round duct is the most efficient and economical means of conveying air. Round duct has a lower initial installed cost than rectangular duct. Its shape results in lower pressure drops. Which, requires less fan horsepower to move the air and, consequently, smaller equipment. The shape also has less surface area and requires less insulation when externally wrapped. Spiral duct is available in longer lengths than rectangular duct, thereby eliminating costly field joints. Spiral lock-seams add rigidity; therefore spiral duct can be fabricated using lighter gauges than longitudinal seam duct. Operating costs are also lower. The smaller surface area of round duct allow less heat loss or gain and are more energy efficient. Also, seams and joints are more tightly sealed resulting in less leakage and wasted energy. The acoustic performance of round duct is superior because their curved surfaces allow less breakout noise.
     These ducts not only perform better, they also look better. Many architects and designers are using the aesthetically pleasing shapes of round duct as unique and integral elements in their designs.

     Finally, round duct can help promote healthier indoor environments. Less surface area, no corners and better airflow reduce the chance of dirt and grime accumulating inside the duct and becoming a breeding ground for bacterial growth.


                                                   Benefits of using Spiral duct
Installed cost – Industry estimates are that the total installed cost of spiral duct,after taking into consideration many factors, is up to 50% less than rectangular duct, with an average of 37%.
Quicker installation – With spiral duct being produced up to 20-ft.(standard is 10-ft.) lengths vs.5-ft. runs for rectangular, installation can proceed more quickly. Its lighter weight and need for fewer supporting components also require fewer workers for installation.
Components and parts – Since spiral duct comes in standardized sizes, so too do the necessary components, such a hangers. These are usually readily available.
Less duct wrap needed – With a smaller surface area (about 17%), than rectangular duct spiral ductwork requires less duct wrap when wrap is specified. Not only is product cost lessened, but so too is labor costs because of the minimal surface area.
Delivery and storage – Spiral duct is a stock item (3”-24”), leading to its quick availability. It can be more easily transported and stored because of its lighter weight and ability to nest together duct in various sizes.
Leakage – Properly sealed square duct is anticipated to leak twice as much as round spiral for an equivalent surface area (SMACNA/ANSI HVAC Air Duct Leakage Test Manual---2011, leakage class 4 versus leakage class 2) and with 17% more surface area that square duct is expected to leak 2.35 times as much as the round spiral duct.
Energy savings – An airtight system means that conditioned air is delivered at the desired temperature, keeping the cost of air distribution to a minimum. And a spiral system provides equal internal pressure, allowing air to flow more evenly.
Space misconception – The assumption is mistakenly made that spiral duct requires more space to install than rectangular. The fact is that it is rectangular duct that requires additional space to accommodate connections and reinforcements.
Comfort – Air delivered at the desired temperature naturally creates a more comfortable environment for the occupants.
Increased fresh air intake – One of the remedies for IAQ problems is increased fresh air intake. Airtight ducts make it more economical to meet this need.
Elimination of VOC off-gassing – Rectangular ductwork usually includes the use of solvent-based sealant at each connection. These types of sealants, which are not used with spiral duct, have been found to emit VOCs, which may have adverse health effects.
Sound attenuation – The pressure differential that exists in rectangular ductwork that creates noise breakout in HVAC systems is not present in spiral duct because of the equalized pressure within.
Easier air flow measurement – Accurate and inexpensive devices for spiral duct enable regular checkups and monitoring.
Fewer measurement sites needed – Air flow measurement can be performed at fewer sites when spiral duct is present.
Effective duct cleaning – Industry-approved duct cleaning methods and
equipment are less expensive and more effective within spiral ductwork.

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