All About Spirals
Shoemaker Mfg. leads the HVAC industry with its comprehensive spiral grille collection, perfectly blending aesthetics and functionality for exposed ceiling designs. Featuring adjustable blades, galvanized steel construction, nylon bushings to prevent rattling, and foam gaskets for an airtight seal, Shoemaker spirals come in single or double deflection models. While dampers are not standard, each spiral can be paired with a screw-driver operated opposed blade damper or fitted with a full or half scoop if needed. Choose from ten powder coat designer colors or opt for custom colors to match ducting.
Spiral Subgroups
Radial Spirals
Radial Spirals, or Radius Spiral Pipe Grilles, feature a one-piece curved frame with a gasket for a flush fit to the spiral pipe. Their adjustable blades allow for versatile airflow control in up to four directions. Sized to fit specific spiral pipe dimensions, details are available in the accompanying tables and "How to Measure" brochure for easy selection.Series include:
RS34 and RS52
RS34 and RS52
Transition Box Spirals
Transition Box Spirals offer versatility with face types like linear bar, perforated, lattice, or standard blade. The SD Series Grilles, including SD34 and SD52 models, ensure an airtight fit with a curved saddle and gasket, while the transition box keeps the damper out of the air stream for efficiency. For sizing details, refer to the accompanying tables and "How to Measure" brochure.Series include:
SD34 and SD52
SD34 and SD52
Universal Spirals
Universal Spiral Grilles flexibly fit pipe sizes from 4” to 48”, ideal for wholesale distributors with uncertain duct sizing. With two high-quality foam gasketing options, they ensure a tight seal, boosting efficiency.Series include:
USR34 and USR52
USR34 and USR52
Spiral Duct Grille Options
Product Options
RS Series
RS52
RS34
SD Series
SD52
SD34
USR Series
USR52
USR34
Single Deflection
N/A
N/A
N/A
Double Deflection
N/A
N/A
N/A
Opposed Blade Damper
Full Scoop
Half Scoop
Adjustable Airfoil Blades
N/A
N/A
N/A
N/A
Linear Face
N/A
N/A
N/A
N/A
Lattice Face
N/A
N/A
N/A
N/A
Perforated Face
Designer/Std. Colors
Made to fit a specific spiral size
N/A
N/A
Made to fit a range of spiral sizes
N/A
N/A
N/A
N/A
RS34
RADIUS SPIRAL PIPE GRILLE (DOUBLE DEFLECTION)
RS52
RADIUS SPIRAL PIPE GRILLE (SINGLE DEFLECTION)
RS-SS
STAINLESS STEEL RADIUS SPIRAL GRILLE
SD34
TRANSITION BOX SPIRAL PIPE GRILLE (DOUBLE DEFLECTION)
SD52
TRANSITION BOX SPIRAL PIPE GRILLE (SINGLE DEFLECTION)
USR34
UNIVERSAL SPIRAL GRILLE (DOUBLE DEFLECTION)
USR52
UNIVERSAL SPIRAL GRILLE (SINGLE DEFLECTION)
DLS
SPIRAL DUCT MOUNT DRUM LOUVER
Chart shows overall dimensions of product based on product height and spiral pipe size. For example: RS34-12x6 on 10" spiral pipe will have a radius height of 2 1/2" and an overall height of 7".
RS34 Series Size Chart
Product Height
Dimension"
4
A
4
A
4
A
4
A
4
A
4
A
8"DIA.
10"DIA.
12"DIA.
14"DIA.
16"DIA.
18"DIA.
20"DIA.
22"DIA.
24"DIA.
26"DIA.
28"DIA.
30"DIA.
32"DIA.
34"DIA.
36"DIA.
38"DIA.
40"DIA.
42"DIA.
44"DIA.
46"DIA.
48"DIA.
2 1/8
2
2
2
2
2
1 7/8
1 7/8
1 7/8
1 7/8
1 7/8
1 7/8
1 7/8
1 7/8
1 7/8
1 7/8
1 7/8
1 7/8
1 7/8
1 3/4
1 3/4
5 3/8
5 1/2
5 5/8
5 3/4
5 3/4
5 3/4
5 3/4
5 3/4
5 7/8
5 7/8
5 7/8
5 7/8
5 7/8
5 7/8
5 7/8
5 7/8
5 7/8
5 7/8
5 7/8
5 7/8
5 7/8
N/A
2 1/2
2 3/8
2 1/4
2 1/4
2 1/8
2 1/8
2
2
2
2
2
2
2
2
1 7/8
1 7/8
1 7/8
1 7/8
1 7/8
1 7/8
N/A
7
7 3/8
7 1/2
7 1/2
7 5/8
7 5/8
7 3/4
7 3/4
7 3/4
7 3/4
7 3/4
7 3/4
7 3/4
7 3/4
7 3/4
7 3/4
7 3/4
7 3/4
7 3/4
7 3/4
N/A
N/A
3
2 3/4
2 5/8
2 1/2
2 1/2
2 3/8
2 1/4
2 1/4
2 1/4
2 1/8
2 1/8
2 1/8
2 1/8
2 1/8
2 1/8
2 1/8
2
2
2
N/A
N/A
8 3/4
9 1/8
9 1/4
9 3/8
9 1/2
9 4/8
9 5/8
9 5/8
9 5/8
9 3/4
9 3/4
9 3/4
9 3/4
9 3/4
9 3/4
9 3/4
9 3/4
9 3/4
9 3/4
RS34
RADIUS SPIRAL PIPE GRILLE (DOUBLE DEFLECTION)
RS52
RADIUS SPIRAL PIPE GRILLE (SINGLE DEFLECTION)
RS-SS
STAINLESS STEEL RADIUS SPIRAL GRILLE
DLS
SPIRAL DUCT MOUNT DRUM LOUVER
Chart shows overall dimensions of product based on product height and spiral pipe size. For example: RS34-12x6 on 10" spiral pipe will have a radius height of 5" and an overall width of 9".
RS34 Series Size Chart
Product Height
Dimension"
4
A
B
6
A
B
8
A
B
10
A
B
12
A
B
8"DIA.
10"DIA.
12"DIA.
14"DIA.
16"DIA.
18"DIA.
20"DIA.
22"DIA.
24"DIA.
26"DIA.
28"DIA.
30"DIA.
32"DIA.
34"DIA.
36"DIA.
38"DIA.
40"DIA.
42"DIA.
44"DIA.
46"DIA.
48"DIA.
5
4 7/8
4 7/8
4 3/4
4 3/4
4 5/8
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
4 3/8
4 3/8
4 3/8
4 3/8
7 1/8
7 3/8
7 1/2
7 5/8
7 3/4
7 7/8
7 7/8
7 7/8
7 7/8
7 7/8
7 7/8
7 7/8
7 7/8
7 7/8
7 7/8
7 7/8
8
8
8
8
8
N/A
5
5
4 7/8
4 3/4
4 3/4
4 5/8
4 5/8
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
4 3/8
4 3/8
4 3/8
4 3/8
N/A
9
9 1/4
9 1/2
9 5/8
9 3/4
9 7/8
9 7/8
9 7/8
9 7/8
9 7/8
9 7/8
9 7/8
9 7/8
9 7/8
9 7/8
9 7/8
10
10
10
10
N/A
N/A
5 1/8
5
4 7/8
4 3/4
4 3/4
4 5/8
4 5/8
4 5/8
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
4 3/8
4 3/8
4 3/8
N/A
N/A
10 7/8
11 1/4
11 3/8
11 5/8
11 3/4
11 7/8
11 7/8
11 7/8
11 7/8
11 7/8
11 7/8
11 7/8
11 7/8
11 7/8
11 7/8
11 7/8
12
12
12
N/A
N/A
N/A
5
5
4 7/8
4 3/4
4 3/4
4 5/8
4 5/8
5 5/8
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
4 3/8
4 3/8
N/A
N/A
N/A
13
13 1/4
13 3/8
13 1/2
13 5/8
13 5/8
13 7/8
13 7/8
13 7/8
13 7/8
13 7/8
13 7/8
13 7/8
13 7/8
13 7/8
13 7/8
14
14
N/A
N/A
N/A
N/A
5 1/8
5
4 7/8
4 7/8
4 7/8
4 3/4
4 5/8
4 5/8
4 5/8
4 5/8
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
4 1/2
N/A
N/A
N/A
N/A
14 7/8
15 1/8
15 3/8
15 1/2
15 5/8
15 7/8
15 7/8
15 7/8
15 7/8
15 7/8
15 7/8
15 7/8
15 7/8
15 7/8
15 7/8
15 7/8
15 7/8
Chart denotes spiral pipe diameter range compatible with product size. Example: USR34-10x3 fits pipe sizes 6" through 24" diameter.
RS34 Series Size Chart
Sizes Offered
Product Height
3
4
6
8
10
12
Product Width
10
12
14
16
18
20
24
26
36
6" - 24" dia.
6" - 24" dia.
6" - 24" dia.
6" - 24" dia.
6" - 24" dia.
6" - 24" dia.
6" - 24" dia.
6" - 24" dia.
6" - 24" dia.
10" - 24" dia.
10" - 24" dia.
10" - 24" dia.
10" - 24" dia.
10" - 24" dia.
10" - 24" dia.
10" - 24" dia.
10" - 24" dia.
10" - 24" dia.
12" - 24" dia.
12" - 24" dia.
12" - 24" dia.
12" - 24" dia.
12" - 24" dia.
12" - 24" dia.
12" - 24" dia.
12" - 24" dia.
12" - 24" dia.
20" - 36" dia.
20" - 36" dia.
20" - 36" dia.
20" - 36" dia.
20" - 36" dia.
20" - 36" dia.
20" - 36" dia.
20" - 36" dia.
20" - 36" dia.
30" - 48" dia.
30" - 48" dia.
30" - 48" dia.
30" - 48" dia.
30" - 48" dia.
30" - 48" dia.
30" - 48" dia.
30" - 48" dia.
30" - 48" dia.
42" - 48" dia.
42" - 48" dia.
42" - 48" dia.
42" - 48" dia.
42" - 48" dia.
42" - 48" dia.
42" - 48" dia.
42" - 48" dia.
42" - 48" dia.
Relevant Literature and Case Studies
Case Studies
Spiral Duct Diffusers Brochure
FAQ
Q: I have a competitor’s spiral that I am trying to match. How can I find out what the Shoemaker Mfg. equivalent is?
A: Use our handy Cross Reference.
Q: Why should I use one particular spiral series over the other?
A: There are many great reasons to use Shoemaker spirals. Select the one that best fits your needs.
- Shoemaker Mfg. manufactures three distinct lines of spirals: the Radial Spiral Pipe Grille, Transition Box Spiral Pipe Grille and the Universal Spiral Grille.
- The Radial Spiral Pipe Grille is flush to the pipe for a clean modern look.
- The Transition Box Spiral Pipe Grille is a style that has been around for years and allows the damper to be out of the airstream.
- The Universal Spiral Grille is more versatile in that one size can fit a range of pipe sizes.
- All three styles are standard without a damper but are available with an optional opposed blade damper (OBD), full scoop (FS), or half scoop (SC).
Q: What kind of damper or air control options are available in the spiral series?
A: The spiral pipe grilles are standard without a damper but are available with an optional opposed blade damper, full scoop, or half scoop. The opposed blade damper (OBD) is recessed screwdriver operated and has blades that oppose each other as they close which provides great air control. The full scoop (FS) is screwdriver operated to lift and lower the scoop which extends the full length of the grille and scoops the air up to flow through the grille. The half scoop (SC) works similarly to the full scoop but does not block the air from flowing past the grille when it is fully open.
Q: Will the Universal Spiral Grille fit on any pipe size?
A: The Universal Spiral Grille is manufactured to fit on a range of sizes based on the grille size. The chart below shows the pipe size range available based on the grille size you are ordering.
Q: Does the spiral pipe grille come with a template so I know what size hole to cut in the duct?
A: The spiral pipe grilles do not have a template. The size of the hole you would cut in the duct would be the size of the grille ordered. For example: if you order a 10X4 spiral pipe grille, the hole size you would cut would be a 10X4.
Q: What type of gaskets are used on the spiral grilles?
A: All three types of spiral grilles have a soft foam gasket to help seal the grille to the duct and reduce air lose. The Universal Spiral Grille also has a dense foam gasket on the ends of the grille to provide a close seal allowing the flexibility to fit on various pipe sizes in the range of that grille size. Below are images of the gaskets.
Q: What type of blades are on the Sprial Grilles?
A: All three spiral grilles have individually adjustable blades that are made of galvanized steel with 2/3" blade spacing. They are available in single deflection (RS52, SD52, USR52) with blades parallel to the shortest dimension or double deflection (RS34, SD34, USR34) with front blades parallel to shortest dimension and back blades parallel to longest dimension.
Q: What if I need more capacity than the spirals listed here can produce?
A: Shoemaker Mfg also carries two different Drum Louver products that are great for long throw applications such as sports arena, gymnasiums, conference centers, industrial plants and other large spaces. See the Drum Louvers (DL) and the Spiral Duct Mount Drum Louver (DLS) product pages and the Spiral Duct Diffuser flyer above.
Q: Can I return spiral grilles if they don’t fit?
A: Because our Radial Spiral Pipe Grilles and Transitions Box Spiral Pipe Grilles are manufactured to the specifications required for each job, we cannot accept returns. For the Universal Spiral Grille, there may be limits to the returns and will need to be approved prior to returning. Please review the appropriate submittals and talk to your Inside Sales Representative to answer any questions you may have, especially about the sizing and measuring before ordering.