What’s a spiral duct? In general, ducts are passages used in heating, ventilation, and air conditioning (HVAC) to deliver and remove air. They can be used in residential or commercial buildings. A spiral or round duct is typically made from galvanized steel and occasionally aluminium.

What is spiral duct work?

About Spiral Ductwork Spiral duct is a rigid spirally wound tube usually made of galvanized steel, but can also be stainless steel, aluminum or copper. It has its seams on the outside, making the inside surface very smooth and having low resistance to airflow.

What is spiral HVAC?

The spiral design of spiral ductwork helps to equalize the pressure as the air flows through the ducts. This not only allows for greater energy efficiency but also reduces the amount of noise that can result from reverberated air pressure. Spiral ductwork requires no additional space.

Is spiral duct expensive?

Getting something for nothing is rare, but by switching from traditional rectangular ductwork to spiral, you can do just that. Spiral ductwork is cheaper to install and cheaper to use throughout the life of the HVAC system.

Does spiral duct leak?

It has long been recognized that spiral duct systems leak a great deal less than comparable rectangular systems. This can be easily explained when looking at the source of leaks, seams and connections.

How is spiral duct made?

The forming process sends the strip through an inner and outer welding stage that moves it in a circular motion to form a spiral. The edges are welded or pinched together to form the duct piece. It is then cut from the machine at the desired length, inspected, tested, and then sent on be installed.

Is spiral duct insulated?

Typically, these systems are insulated with a flexible, blanket-type insulation like Spiral SG. This insulation is wrapped around the exterior of the inner duct, which is then inserted into the outer duct.

Is spiral duct watertight?

In a spiral duct, your air pressure drop is lower when comparing it to the classic rectangular ductwork. … Oval spiral ducts are also watertight – while humidity is easily amplified in a restaurant setting, this reliable form of duct will ensure no water will drip or pool where your customers enjoy their meal.

Is round or square duct better?

Round air ducts are best suited for high-pressure HVAC systems. Their design creates less friction, allowing air to flow easier throughout the building. Rectangular ducts aren’t as efficient with their airflow, which means they can create more harm than good in a high-pressure system.

Is flex ductwork cheaper than rectangular?

Less Expensive – by almost 50%. By the time insulation is added to the cost of standard metal ductwork, the material cost is almost twice that of flexible ductwork that comes pre-insulated. Also, flexible ductwork is faster to install than metal ductwork.

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Does exposed ductwork get hot?

You wouldn’t want to be inside your air ducts when the heating unit is on. The temperatures inside can be as high as 170 F. However, from the outside, the actual ductwork should not be extremely hot. In fact, if the ducts have proper insulation, you should be able to touch them without getting burned.

How do you make exposed ductwork look good?

If you don’t want to go through the hassle of covering up your exposed pipes and ducts, but you also don’t want them to draw too much attention, simply paint them the same color as the ceiling or walls that surround them. Painted in a unifying hue, they will blend in and become part of a cohesive background palette.

What is rectangular ductwork?

Rectangular Duct is the most common type of duct in commercial projects. … When it comes to Rectangular Duct there is a transverse (end to end) connection and a longitudinal connection, either 1 or 2, depending on whether the duct is fabricated in L sections (2 piece duct) or as full wrap duct (1 piece duct).

Is round ductwork cheaper than rectangular?

In many ways, round metal duct work is more economical than rectangular metal duct work as a means of conveying air. … Because it is available in longer lengths, round duct requires fewer costly joints in the field and less sealing.

Can I use Flex Seal on ductwork?

It has a low flame and smoke spread, is low in VOCs, has low odor and dries in just 4-6 hours! That means you can put the unit back into service quickly for a very satisfied customer. Flex Seal can be used for ductwork, interior HVAC walls, wood, concrete, metal, etc.

What is double wall spiral duct?

Dual Wall (also called Double-Wall) Insulated Spiral Pipe Dual wall insulated spiral pipe consists of two concentric spiral pipes with insulation filling the space between the pipes. It is shipped from the factory with the insulation pre-installed, reducing job site labor costs.

What is double wall ductwork?

Double wall duct is constructed with an insulation layer between a solid metal outer shell and either a perforated or solid metal inner shell. … Non-corrugated duct may be specified when the spiral duct is going in a open ceiling in order to give a crisper look.

What is single wall ductwork?

SINGLE WALL ROUND DUCT Single wall spiral pipe is formed from a coil of metal into a rigid tube with a 4-ply spiral lockseam. … Single wall spiral ductwork is not only easy to install, it’s just as easy to seal, offers plenty of energy-efficiency benefits and is visually appealing.

How is ductwork made?

Traditionally, air ductwork is made of sheet metal which was installed first and then lagged with insulation. Today, a sheet metal fabrication shop would commonly fabricate the galvanized steel duct and insulate with duct wrap prior to installation.

What are standard duct sizes?

Rectangular HVAC Duct Sizing Rectangular or square ducting comes in standard sizes ranging from 3 inches by 7 inches to 35 inches by 40 inches. Sizing is based on airflow needs per cubic foot per minute, as well as velocity.

What is the most energy efficient shape of duct?

Round. Round ducts are the most efficient in transporting air. They use less material than rectangular ducts to handle the same amount of air.

Are generally preferred over the circular duct in building as?

Even though circular ducts require the least material for a given flow rate and allowable pressure drop, rectangular ducts are generally preferred in practice as they fit easily into the building construction thus occupying less space, and they are also easy to fabricate.

What gauge is spiral duct?

Gauges – 28 to 16 for galvanized spiral lock-seam, 28 to 18 for stainless steel spiral lock-seams, 0.025” to 0.080” for aluminum spiral lock-seams, 22 gauge to 3/8” for welded longitudinal-seam duct.

How many CFM is a 10 round duct?

Duct Size (Inches)Metal Duct Airflow (CFM)7 inches125 CFM8 inches180 CFM9 inches240 CFM10 inches325 CFM

Why flex duct is bad?

Flexible ductwork not only resists airflow, but is also more susceptible to a poor installation. Any number of factors can go wrong, including a poorly sealed joint, excessive length that lacks support and crumpled sections. Also, the material itself is less durable than sheet metal.

What is the most commonly used ductwork in an HVAC residential system?

Made of galvanized steel or aluminum, rigid sheet metal is the most common type of ductwork. The thick, solid wall makes the duct very durable.

Which duct work is best?

Sheet metal air ducts are the most durable type of air duct construction, and because of their non-porous surface, are the least likely to have mold or biological growth.

Is exposed ductwork more expensive?

Exposed Ductwork Cost More care needs to be taken if the system is exposed throughout the home, rather than just in utility spaces. Depending on how much of your system is exposed, your costs could be on the higher end for the entire project.

Does insulating ductwork help?

Thermal insulation is a great way to minimize energy loss in ducts. Heat loss through the duct walls is an expected and inevitable drain on the system. Effective thermal insulation of the ductwork reduces this heat loss and helps to minimize energy usage.

Can I paint ductwork?

It’s best to use latex paint, and because ducts are located in out-of-the-way places, you can usually get away with using a paintbrush. If the ducts are prominent, though, you may want to spray paint them.

How can I hide my duct work?

1. Create a tray ceiling. …
2. Drop the ceiling in one area to create intimacy. …
3. Create faux rafters. …
4. Use unique soffits when framing out ductwork. …
5. Incorporate ceiling framing with wall framing. …
6. When you can’t beat ’em – embrace them!