HAS-Vent Rectangular Duct

The type and specification of ductwork used in HVAC systems performs an integral role in influencing the indoor air quality for commercial and industrial facilities. Ventilation systems must be appropriately designed and maintained to regulate ambient temperature and humidity levels in properties, with efficient airflow crucial for the removal of air contaminants.

HAS-Vent manufactures an extensive range of rectangular ductwork and fittings, offering ultimate design and configuration flexibility to suit buildings where space comes at a premium. Our ductwork ensures optimal airflow for ventilation, enhancing HVAC system performance in indoor and outdoor environments alike.

Construction, Thickness & Finishing Options:

HAS-Vent ductwork is manufactured from Hot Dipped Galvanised Steel DX51D Z275, all raw material is supplied and certified to the latest version of BS EN IS 9001.

All ductwork and fittings are available with 2 high-quality finishing options:

  • Standard Galvanised Finish Z275
  • Colorduct II – Painted to any RAL colour specified (data sheet available upon request)

The below specifications cover duct sizes up to a maximum longer side of 3000mm. Duct sizes with an aspect ratio greater than 4:1 are not recommended. Although they offer no problems of construction, they increase frictional resistance and the possibility of noise.

Enquiries & Expert Advice:

At HAS-Vent, our ventilation specialists are available to support your ductwork order enquiries, offering industry-leading guidance for technical details and project requirements.

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Why rectangular ducts?

Circular ducts are the most common form of ventilation duct used in commercial and industrial HVAC systems. At HAS-Vent we produce a comprehensive range of circular ducts and fittings that enable efficient air transportation in ventilation systems.

Circular ducts can, however, be difficult to fit into spaces and building layouts, rendering them unsuitable for certain project requirements.

Rectangular ducts provide added flexibility in design, often chosen for their aesthetic appeal and ability to be configured to suit complex ventilation and building layouts. As a result, the ductwork maintains excellent airflow performance with maximised space efficiency serving as an effective alternative to circular ductwork.

HAS-Vent additionally offers a range of flat oval ducts and components, offering an additional option to suit spatial and aesthetic criteria.

To discuss your project and ventilation system requirements, contact our specialist team today for further support and enquiries.

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Low Pressure Ductwork

FLANGED JOINTS

Dimensions in mm

1

2

3

4

5

6

7

8

9

10

11

MIN. SHEET THICKNESS

0.6

0.8

1.0

1.2

DUCT LONGEST SIDE

400

600

800

1000

1250

1600

2000

2500

3000

RATING

SHEET

MAXIMUM SPACING BETWEEN FLANGES AND / OR STIFFENERS

J1/S1

PS

3000

1600

1250

625

SS

3000

3000

1250

625

J2/S2

PS

3000

2000

1600

1250

625

SS

3000

3000

1600

1250

625

J3/S3

PS

3000

2000

1600

1250

1000

800

SS

3000

3000

2000

1600

1250

800

J4/S4

PS

3000

2000

1600

1250

1000

800

800

SS

3000

3000

2000

1600

1250

1000

800

J5/S5

PS

3000

2000

1600

1250

1000

800

800

800

625

SS

3000

3000

2000

1600

1250

1000

800

800

800

J6/S6

PS

3000

2000

1600

1250

1000

800

800

800

800

SS

3000

3000

2000

1600

1250

1000

800

800

800

Medium Pressure Ductwork

FLANGED JOINTS AND STIFFENERS

Dimensions in mm

1

2

3

4

5

6

7

8

9

10

11

MIN. SHEET THICKNESS

0.6

0.8

1.0

1.2

DUCT LONGEST SIDE

400

600

800

1000

1250

1600

2000

2500

3000

RATING

SHEET

MAXIMUM SPACING BETWEEN FLANGES AND / OR STIFFENERS

J1/S1

PS

3000

1250

625

SS

3000

1250

625

J2/S2

PS

3000

1250

1250

625

SS

3000

1600

1250

625

J3/S3

PS

3000

1600

1250

1000

800

SS

3000

3000

1600

1250

800

J4/S4

PS

3000

1600

1250

1000

800

800

SS

3000

3000

1600

1250

1000

800

J5/S5

PS

3000

1600

1250

1000

800

800

800

625

SS

3000

3000

1600

1250

1000

800

800

800

J6/S6

PS

3000

1600

1250

1000

800

800

800

800

625

SS

3000

3000

1600

1250

1000

800

800

800

625

High Pressure Ductwork (Class C)

FLANGED JOINTS AND STIFFENERS

Dimensions in mm

1

2

3

4

5

6

7

8

9

10

MIN. SHEET THICKNESS

0.8

1.0

1.2

DUCT LONGEST SIDE

400

600

800

1000

1250

1600

2000

2500

RATING

SHEET

MAXIMUM SPACING BETWEEN FLANGES AND / OR STIFFENERS

J1/S1

PS

3000

625

SS

3000

625

J2/S2

PS

3000

1250

800

SS

3000

1250

800

J3/S3

PS

3000

1250

1250

800

SS

3000

1250

1250

800

J4/S4

PS

3000

1250

1250

1000

800

SS

3000

1250

1250

1000

800

J5/S5

PS

3000

1250

1250

1000

800

800

625

SS

3000

1250

1250

1000

800

800

625

J6/S6

PS

3000

1250

1250

1000

800

800

800

625

SS

3000

1250

1250

1000

800

800

800

625

Types of Fittings

Mitred Throat Bend


For ducts up to 400mm wide

Examples of 'Hard' and 'Easy' bends

'Hard' signifies rotation in the plane of the longer side of the cross section (top sketch).



'Easy' signifies rotation in the plane of the shorter side of he cross section (bottom sketch)

Short Radius Bend


For ducts up to 400mm wide

Medium Radius Bend

(as illustrated)

Long Radius Bend

Similar but radius = W Applies to any angle




Short Radius Bend with splitters

W mm

Splitters

Splitter Position

A

B

C

401 - 800

1

W / 3

-

-

801 - 1600

2

W / 4

W / 2

-

1601 - 2000

3

W / 8

W / 3

W / 2

Splitters not required in bends of 45° or less

Square Bend - with turning vanes


Mitred elbow - 30° max

Radius Tee - with 'radiussed back plates' and, if required, splitters

Angled Offset

Mitred Offset

Radiussed Offset

Concentric Taper

22.5° max in either plane

Splitters are required for angles greater than 22.5° and should bisect the angle between the sid eand the duct centreline.

Ecccentric Taper

22.5° max in either plane

Splitters are required for angles greater than 22.5° and should bisect the angle between the sid eand the duct centreline.

OffsetTaper

Splitters are required for angles greater than 22.5° and should bisect the angle between the sid eand the duct centreline.

Radiussed Twin Bend

Swan Neck Bend - typically found on roof exhausts i.e. 135° angle

Swept Branch

Square Tee with turning vanes

Breeches Piece

'Y' Piece

Rectangular to Round Transformation

Rectangular to Flat Oval Transformation

Square Branch

Angled Branch

Shoe Branch

Branch Duct Width (W) mm

Dimension (A) mm

Up to 200

75

" 300

100

" 400

125

" 600

150

Over 600

200

Bell Mouth Branch

Branch Duct Width (W) mm

Dimension (A) mm

Up to 200

75

" 300

100

" 400

125

" 600

150

Over 600

200

Bell Mouth

Branch Duct Width (W) mm

Dimension (A) mm

Up to 200

75

" 300

100

" 400

125

" 600

150

Over 600

200

Duct Supports

Supports for rectangular horizontal ductwork

Longest Side

HANGERS

BEARERS

Maximum Spacing's

Screwed Rod

Flat Strap Fig 156/164

Stirrups

"Z" cm³ x-x
Fig 155 / 163

Up to 400

6

25 x 0.5 Plain or Perforated

N/A

0.40

3000

401 - 600

8

30 x 3 flat

N/A

0.70

3000

601 - 1000

8

N/A

N/A

1.50

3000

1001 - 1500

10

N/A

N/A

2.10

2500

1501 - 2000

10

N/A

N/A

3.05

2500

2001 - 3000

12

N/A

N/A

4.45

2500

Bespoke ductwork builds

From small to industrial-scale ventilation system projects, HAS-Vent is equipped with the expertise to design, advise and deliver bespoke ductwork builds for your building/facility. Our expert team will analyse your technical drawings to determine which products would suit your project, providing tailored designs with quotes to assist you with your project.

Our rectangular ductwork and fittings are manufactured in-house in our modern production facilities to the highest standards. Regional and national delivery is then available from our fleet of strategically positioned delivery vehicles to provide swift delivery for your project’s needs.

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rectduct

About us

We are a leading supplier and British custom ventilation manufacturer to the construction industry, we make it our mission to offer excellent value and superior customer support.
We manufacture and supply Flat Oval, Circular, Rectangular and Colorduct II ductwork from our modern production facility in the Midlands. Get in touch to see how we can support your project.

Want to know more?

Download our Engineered Air Solutions brochure or contact our expert team to discuss your requirements today!

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