Air duct construction, fittings & industrial engineering

Coolenvi™ supplies precision-manufactured air duct components, fittings and special construction solutions for modern ventilation and ducting systems. The range includes standardised and custom solutions for building services, industrial applications, process air systems, data centres, clean rooms and energy-efficient HVAC systems. In addition, components for industrial applications, containment trays for media and groundwater protection, and metal construction solutions ensure safe, airtight and standards-compliant media handling.

Comparison of Airtightness Classes for Air Duct Systems

DIN EN 16798-3	DIN EN 13779	Leakage Formula (l/s·m²)	Example +500 Pa	Example −500 Pa	Example +1,000 Pa	Example −1,000 Pa
ATC 5	A (Standard)	0.027 × p^0.65	1.53	1.53	2.41	2.41
ATC 4	B (Recommended)	0.009 × p^0.65	0.51	0.51	0.80	0.80
ATC 3	C (Special applications)	0.003 × p^0.65	0.17	0.17	0.27	0.27
ATC 2	D (Grease-tight, watertight)	0.001 × p^0.65	0.06	0.06	0.09	0.09
ATC 1	–	0.00033 × p^0.65	0.02	0.02	0.03	0.03

Note: Leakage rates apply equally to positive and negative pressure testing. The absolute value of test pressure p [Pa] is decisive. Actual test pressures are project-specific. Prices are only valid for orders placed as an XML file.

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Now select the right category for your Air Duct System

Installation and Fixing Materials

All essential components for professional installation – from screws and nuts to brackets, anchors and fixing systems.

Condensate Drainage

Efficient solutions for safe and clean condensate removal.

Straight Air Ducts

Hygienic ventilation ducts in rectangular systems with accessories and components.

Straight Rectangular Air Ducts for Your Systems

Here you find straight air ducts as the base for efficient air distribution systems. Rectangular fittings such as bends and transitions are shown in the next section.

Straight Air Ducting - rectangular stainless steel 1.4301

Item - Ductype: Straight Air Ducting - rectangular

Stainless steel 1.4301 air duct section with edge dimensions from 300 to 2000 mm. Both cross-sections are equipped as standard with SBM flange frames for connection to common duct systems. Billing is carried out as a form component based on a standard length of 900 mm with a minimum billing area of 1 m². For standard lengths from 900 mm, billing is made in full m² units to account for sheet metal waste and manufacturing effort. Air ducts and fittings are made of galvanised steel sheet (e.g. according to EN 1505/1507). Components are typically produced with folded seams, while fittings use Pittsburgh or snap-lock seams. SBM flange connections are sealed as standard with sealing compound. Special materials or designs are charged separately based on effort. Suitable for ventilation systems transporting non-aggressive air. Standard design: ATC 5 according to DIN EN 16798 (leakage class A according to DIN EN 13779)Pressure range from +1,000 Pa to -500 Pa Deviations such as other leakage classes, pressure classes or special options are subject to additional charges and must be ordered separately. Custom-made products are excluded from withdrawal and return rights. Paid recycling return is available.

DKK 921.50*

Straight Air Ducting - rectangular galvanized

Item - Ductype: Straight Air Ducting - rectangular

Galvanised air duct section with edge dimensions from 300 to 2000 mm. Both cross-sections are equipped as standard with SBM flange frames for connection to common duct systems. Billing is carried out as a form component based on a standard length of 900 mm with a minimum billing area of 1 m². For standard lengths from 900 mm, billing is made in full m² units to account for sheet metal waste and manufacturing effort. Air ducts and fittings are made of galvanised steel sheet (e.g. according to EN 1505/1507). Components are typically produced with folded seams, while fittings use Pittsburgh or snap-lock seams. SBM flange connections are sealed as standard with sealing compound. Special materials or designs are charged separately based on effort. Suitable for ventilation systems transporting non-aggressive air. Standard design: ATC 5 according to DIN EN 16798 (leakage class A according to DIN EN 13779)Pressure range from +1,000 Pa to -500 Pa Deviations such as other leakage classes, pressure classes or special options are subject to additional charges and must be ordered separately. Custom-made products are excluded from withdrawal and return rights. Paid recycling return is available.

DKK 217.90*

New

Flexible Air Duct Connector with SBM Flange - Basic Price

Item - Ductype: Straight Air Ducting - rectangular

Galvanised air duct fitting as a flexible fabric connector with edge dimensions from 300 to 2000 mm. Both cross-sections are equipped as standard with SBM flange frames for connection to common duct systems, air handling units, fire dampers or acoustic/vibration decoupling. Billing for this fitting is based on a base price regardless of size. Taking material waste and manufacturing effort into account, billing is carried out in full linear metres as a separate item. The duct fitting is manufactured from galvanised steel sheet (e.g. according to EN 1505/1507). Components are typically spot-welded. SBM flange connections are sealed as standard with sealing compound. Special materials or designs are charged separately based on effort. Suitable for ventilation systems transporting non-aggressive air. Optional equipotential bonding cables are available. Standard design: ATC 5 according to DIN EN 16798 (leakage class A according to DIN EN 13779)Pressure range from +1,000 Pa to -500 Pa Deviations such as other leakage classes, pressure classes or special options are subject to additional charges and must be ordered separately. Custom-made products are excluded from return rights. Paid recycling return is available.

DKK 283.71*

Flexible Air Duct Connector Glasfiber/PU 45/60/45 - Price Running Meter

Item - Ductype: Form Air Duct Fitting - rectangular

For each galvanised air duct fitting as a flexible fabric connector, this PVC material with galvanised sheet edges provides optimal compatibility for standard SBM flange frames for connection to common duct components. Billing for this fitting is carried out exclusively in full linear metres as an additional item to the base price of the fabric connector. If this item is ordered without the base fabric connector product, only the ordered linear metres are supplied without frame components, etc. Suitable for ventilation systems transporting non-aggressive air. Optional equipotential bonding cables are available. Standard design: ATC 5 according to DIN EN 16798 (leakage class A according to DIN EN 13779)Pressure range from +1,000 Pa to -500 Pa L=150mm Deviations such as other leakage classes, pressure classes or special options are subject to additional charges and must be ordered separately. Custom-made products are excluded from return rights. Paid recycling return is available.

DKK 329.28*

Duct Volume Damper - Manual Version with Lever

Item - Ductype: Straight Air Ducting - rectangular

For manual or basic air volume control, a professionally manufactured damper blade with external operating lever is installed into air ducts or smooth pipes, such as spiral wound ducting. Damper blades must be ordered as separate components, as this service covers workshop labour only. Billing is based on a unit price as workshop work. For dimensions exceeding 1 m², the order quantity must be considered accordingly. Custom-made products are excluded from return and withdrawal rights. Paid recycling return is available.

DKK 489.29*

Fittings for Rectangular Air Duct Systems

Here you can find essential fittings such as rectangular bends, tees, reducers and transitions for complete air duct installations. These components ensure flexible routing and efficient airflow distribution.

Form Air Duct Fitting - rectangular stainless steel 1.4301

Item - Ductype: Form Air Duct Fitting - rectangular

Stainless steel ventilation duct fitting with edge dimensions from 300 to 2000 mm. Both cross-sections are equipped as standard with SBM flange frames for connection to common duct systems. Billing is based on a duct fitting with a minimum billing area of 1 m² if the sheet metal requirement for smaller components falls below this value. For fittings larger than 1 m², billing is carried out in full m² units to account for sheet metal waste and manufacturing effort. Duct fittings are manufactured from galvanised steel sheet (e.g. according to EN 1505/1507). Components are typically produced with Pittsburgh or snap-lock seams. SBM flange connections are sealed as standard with sealing compound. Special materials or designs are charged separately based on effort. Suitable for ventilation systems transporting non-aggressive air. Standard design: ATC 5 according to DIN EN 16798 (leakage class A according to DIN EN 13779)Pressure range from +1,000 Pa to -500 Pa Deviations such as other leakage classes, pressure classes or special options are subject to additional charges and must be ordered separately. Custom-made products are excluded from withdrawal and return rights. Paid recycling return is available.

DKK 1,090.02*

Sheet metal cut without bending - in galvanised duct steel up to 0.88 mm

Item - Ductype: Customising

Galvanised air ducts or fittings occasionally require sheet metal cut-outs for repairs, cladding or modifications. Billing is based on the fitting price with a minimum charge of 1 m². For cut-outs above 1 m², billing is done in full square metre units to account for material waste and manufacturing effort. Custom-made products are excluded from return and withdrawal rights. Paid recycling return is available.

DKK 283.26*

Form Air Duct Fitting - rectangular galvanized

Item - Ductype: Form Air Duct Fitting - rectangular

Galvanised ventilation duct fitting with edge dimensions from 300 to 2000 mm. Both cross-sections are equipped as standard with SBM flange frames for connection to common duct systems. Billing is based on a duct fitting with a minimum billing area of 1 m² if the sheet metal requirement for smaller components falls below this value. For fittings larger than 1 m², billing is carried out in full m² units to account for sheet metal waste and manufacturing effort. Duct fittings are manufactured from galvanised steel sheet (e.g. according to EN 1505/1507). Components are typically produced with Pittsburgh or snap-lock seams. SBM flange connections are sealed as standard with sealing compound. Special materials or designs are charged separately based on effort. Suitable for ventilation systems transporting non-aggressive air. Standard design: ATC 5 according to DIN EN 16798 (leakage class A according to DIN EN 13779)Pressure range from +1,000 Pa to -500 Pa Deviations such as other leakage classes, pressure classes or special options are subject to additional charges and must be ordered separately. Custom-made products are excluded from withdrawal and return rights. Paid recycling return is available.

DKK 283.26*

Duct Volume Damper - Manual Version with Lever

Item - Ductype: Straight Air Ducting - rectangular

For manual or basic air volume control, a professionally manufactured damper blade with external operating lever is installed into air ducts or smooth pipes, such as spiral wound ducting. Damper blades must be ordered as separate components, as this service covers workshop labour only. Billing is based on a unit price as workshop work. For dimensions exceeding 1 m², the order quantity must be considered accordingly. Custom-made products are excluded from return and withdrawal rights. Paid recycling return is available.

DKK 489.29*

Form Air Duct Fitting - transition round/rectangular EL300 mm SYM galvanized

Item - Quantity: 1 Pc

Galvanized ventilation transition piece from round to rectangular in symmetrical design with an edge length of 300 mm. The rectangular side is equipped with a standard SBM flange frame for connection to common duct systems. Billing is based on a minimum area of 1 m² per form piece, regardless of the actual component size. Suitable for HVAC and ducting applications, especially for transitions between round pipe and rectangular duct systems in galvanized execution. Standard design: ATC 5 according to DIN EN 16798 (leakage class A according to DIN EN 13779)Pressure range from +1,000 Pa to -500 Pa Deviations from the standard design such as other leakage classes, pressure classes or special options are subject to additional charges and must be ordered separately. Custom-manufactured products are excluded from withdrawal and return rights. Paid return for recycling is available.

DKK 556.96*

Form Air Duct Fitting - transition round/rectangular EL300 mm ASYM galvanized

Item - Ductype: Reducer - rectangular/round

Galvanized ventilation transition piece from round to rectangular in asymmetrical design with an edge length of 300 mm. The rectangular side is equipped with a standard SBM flange frame for connection to common duct systems. Billing is based on a minimum area of 1 m² per form piece, regardless of the actual component size. Suitable for HVAC and ducting applications, especially for transitions between round pipe and rectangular duct systems in galvanized execution. Standard design: ATC 5 according to DIN EN 16798 (leakage class A according to DIN EN 13779)Pressure range from +1,000 Pa to -500 Pa Deviations from the standard design such as other leakage classes, pressure classes or special options are subject to additional charges and must be ordered separately. Custom-manufactured products are excluded from withdrawal and return rights. Paid return for recycling is available.

DKK 928.67*

Form Air Duct Fitting - transition round/rectangular EL500 mm SYM galvanized

Item - Ductype: Reducer - rectangular/round

Galvanized round-to-square ventilation transition piece in a symmetrical design with an edge length of 301-500 mm. The square end is equipped with an SBM flange frame as standard and is designed for connection to common duct systems. Billing is based on a minimum area of 1 m² per fitting, regardless of the actual component size. Suitable for ventilation and ducting applications, especially for transitions between round and rectangular duct systems in a galvanized finish. Standard version: ATC 5 according to DIN EN 16798 (Tightness class A according to DIN EN 13779)Pressure range from +1,000 Pa to -500 Pa Deviations from the standard version, such as other tightness classes, pressure classes, or special options, are subject to additional charges and must be ordered separately. Custom-made products are excluded from the right of withdrawal and return. Return for recycling is possible for a fee.

DKK 936.74*

Form Air Duct Fitting - transition round/rectangular EL1000 mm SYM galvanized

Item - Ductype: Reducer - rectangular/round

Galvanized ventilation transition piece from round to rectangular in symmetrical design with a edge length of 501-1000 mm. The rectangular side is equipped with a standard SBM flange frame for connection to common duct systems. Billing is based on a minimum area of 1 m² per form piece, regardless of the actual component size. Suitable for HVAC and ducting applications, especially for transitions between round pipe and rectangular duct systems in galvanized execution. Standard design: ATC 5 according to DIN EN 16798 (leakage class A according to DIN EN 13779)Pressure range from +1,000 Pa to -500 Pa Deviations from the standard design such as other leakage classes, pressure classes or special options are subject to additional charges and must be ordered separately. Custom-manufactured products are excluded from withdrawal and return rights. Paid return for recycling is available.

DKK 951.38*

Form Air Duct Fitting - transition round/rectangular EL500 mm ASYM galvanized

Item - Ductype: Reducer - rectangular/round

Galvanized round-to-square ventilation transition piece in a asymmetrical design with an edge length of 301-500 mm. The square end is equipped with an SBM flange frame as standard and is designed for connection to common duct systems. Billing is based on a minimum area of 1 m² per fitting, regardless of the actual component size. Suitable for ventilation and ducting applications, especially for transitions between round and rectangular duct systems in a galvanized finish. Standard version: ATC 5 according to DIN EN 16798 (Tightness class A according to DIN EN 13779)Pressure range from +1,000 Pa to -500 Pa Deviations from the standard version, such as other tightness classes, pressure classes, or special options, are subject to additional charges and must be ordered separately. Custom-made products are excluded from the right of withdrawal and return. Return for recycling is possible for a fee.

DKK 951.68*

Form Air Duct Fitting - transition round/rectangular EL1000 mm ASYM galvanized

Item - Ductype: Reducer - rectangular/round

Galvanized ventilation transition piece from round to rectangular in asymmetrical design with a edge length of 501-1000 mm. The rectangular side is equipped with a standard SBM flange frame for connection to common duct systems. Billing is based on a minimum area of 1 m² per form piece, regardless of the actual component size. Suitable for HVAC and ducting applications, especially for transitions between round pipe and rectangular duct systems in galvanized execution. Standard design: ATC 5 according to DIN EN 16798 (leakage class A according to DIN EN 13779)Pressure range from +1,000 Pa to -500 Pa Deviations from the standard design such as other leakage classes, pressure classes or special options are subject to additional charges and must be ordered separately. Custom-manufactured products are excluded from withdrawal and return rights. Paid return for recycling is available.

DKK 1,136.26*

Form Air Duct Fitting - transition round/rectangular EL2000 mm SYM galvanized

Item - Ductype: Reducer - rectangular/round

Galvanized ventilation transition piece from round to rectangular in symmetrical design with a edge length of 1001-2000 mm. The rectangular side is equipped with a standard SBM flange frame for connection to common duct systems. Billing is based on a minimum area of 1 m² per form piece, regardless of the actual component size. Suitable for HVAC and ducting applications, especially for transitions between round pipe and rectangular duct systems in galvanized execution. Standard design: ATC 5 according to DIN EN 16798 (leakage class A according to DIN EN 13779)Pressure range from +1,000 Pa to -500 Pa Deviations from the standard design such as other leakage classes, pressure classes or special options are subject to additional charges and must be ordered separately. Custom-manufactured products are excluded from withdrawal and return rights. Paid return for recycling is available.

DKK 1,729.68*

Form Air Duct Fitting - transition round/rectangular EL2000 mm ASYM galvanized

Item - Ductype: Reducer - rectangular/round

Galvanized ventilation transition piece from round to rectangular in asymmetrical design with a edge length of 1001-2000 mm. The rectangular side is equipped with a standard SBM flange frame for connection to common duct systems. Billing is based on a minimum area of 1 m² per form piece, regardless of the actual component size. Suitable for HVAC and ducting applications, especially for transitions between round pipe and rectangular duct systems in galvanized execution. Standard design: ATC 5 according to DIN EN 16798 (leakage class A according to DIN EN 13779)Pressure range from +1,000 Pa to -500 Pa Deviations from the standard design such as other leakage classes, pressure classes or special options are subject to additional charges and must be ordered separately. Custom-manufactured products are excluded from withdrawal and return rights. Paid return for recycling is available.

DKK 1,802.66*

Straight Spiral Ducts for Your Ventilation System

Here you find straight spiral ducts as the foundation for efficient air distribution systems. Fittings such as elbows, branches and reducers are shown in the next section.

New

Alu-Flex Pipe Stretch DN 224 L=5 m

Item - Ductype: Straight Air Ducting - round

Flexible aluminium flex duct, 2-layer design, compressible and extendable up to approx. 5 m.

Content: 5 lm (DKK 132.97* / 1 lm)

DKK 664.83*

New

Alu-Flex Pipe Stretch DN 400 L=5 m

Item - Ductype: Straight Air Ducting - round

Flexible aluminium flex duct, 2-layer design, compressible and extendable up to approx. 5 m.

Content: 5 lm (DKK 307.02* / 1 lm)

DKK 1,535.09*

New

Alu-Flex Pipe Stretch DN 80 L=5 m

Item - Ductype: Straight Air Ducting - round

Flexible aluminium flex duct, 2-layer design, compressible and extendable up to approx. 5 m.

Content: 5 lm (DKK 45.57* / 1 lm)

DKK 227.84*

Spiral Seam Duct L=3M DN1000

Item - Ductype: Straight Air Ducting - round

Billing is carried out as a form component based on a standard length of 3000 mm with a minimum billing area of this length m. Special materials or designs are charged separately based on effort. Suitable for ventilation systems transporting non-aggressive air. Deviations such as other leakage classes, pressure classes or special options are subject to additional charges and must be ordered separately. Custom-made products are excluded from withdrawal and return rights. Paid recycling return is available.

Content: 3 lm (DKK 2,096.58* / 1 lm)

DKK 6,289.74*

Spiral Seam Duct L=3M DN560

Item - Ductype: Straight Air Ducting - round

Billing is carried out as a form component based on a standard length of 3000 mm with a minimum billing area of this length m. Special materials or designs are charged separately based on effort. Suitable for ventilation systems transporting non-aggressive air. Deviations such as other leakage classes, pressure classes or special options are subject to additional charges and must be ordered separately. Custom-made products are excluded from withdrawal and return rights. Paid recycling return is available.

Content: 3 lm (DKK 761.94* / 1 lm)

DKK 2,285.82*

Round Fittings for Spiral Duct Systems

Here you find round duct fittings including elbows, branches, reducers and additional accessories for spiral duct systems. Designed for quick, airtight installation in ventilation and air conditioning systems.

New