In air handling unit manufacturing, the quality of an assembly starts with the details of its frame construction.

While fans, filters and heat exchangers receive much of the attention, mechanical components such as corner connectors also play an important role in the construction of an AHU casing.

Corner connectors are used to bring frame profiles together at defined connection points. Their geometry, material and compatibility with the selected profile system should be evaluated carefully during the design and manufacturing process.

Choosing the right AHU frame corner connectors is therefore not simply a matter of selecting a product with a matching nominal size.

So, what should AHU manufacturers consider when choosing corner connectors?

In this guide, we explore the main selection criteria, compare plastic and aluminum options, and introduce different corner connector configurations available in the AYS product range.

WHAT ARE CORNER CONNECTORS IN AIR HANDLING UNITS?

Corner connectors are mechanical components used to connect profiles at the corners of air handling unit frames.

In modular AHU construction, frame profiles form part of the casing structure, supporting the overall assembly of panels and other components.

Corner connectors provide a defined joining geometry between the corresponding frame members.

Depending on the frame design, manufacturers may require different connector configurations, materials and dimensions.

For this reason, the correct corner connector must be selected according to the actual frame construction, rather than its appearance alone.

1. START WITH AHU FRAME PROFILE COMPATIBILITY

The first step in selecting a corner connector is identifying the profile system used in the air handling unit.

AHU manufacturers work with different frame geometries and nominal dimensions.

The AYS product catalogue includes plastic corner connectors with designations such as:

• P0002 – 40-25 Plastic Corner
• P0004 – 50-30 mm Plastic Corner
• P0011 – 50 mm Hygienic Plastic Corner
• P0023 – 50-50 mm Plastic Radius Corner
• P0026 – 50 mm Plastic Corner

These examples demonstrate the variety of connector geometries available for different frame designs.

However, two connectors with similar nominal dimensions are not necessarily interchangeable.

WHAT SHOULD YOU CHECK?

Before selecting a component, compare the connector's technical drawing with the intended frame profile.

Pay particular attention to the insertion geometry, cross-sectional shape, connection dimensions and positioning of the adjoining profiles.

Important: A product described as a 50 mm corner connector should not automatically be considered compatible with every 50 mm AHU frame.

Technical verification is essential.

2. CHOOSE BETWEEN PLASTIC AND ALUMINUM CORNER CONNECTORS

Material selection is another important part of AHU frame design.

Different materials may be specified according to the mechanical design, manufacturing approach and application requirements.

AYS offers both plastic and aluminum corner connector options.

PLASTIC CORNER CONNECTORS

The relevant plastic corner connectors presented in the AYS catalogue are manufactured from Polyamide PA6 with 30% glass-fiber reinforcement, as specified in their product information.

Examples include:

P0002 – 40-25 Plastic Corner

A plastic connector with a geometry intended for its corresponding frame configuration.

P0011 – 50 mm Hygienic Plastic Corner

A model included in the AYS hygienic plastic corner range.

P0026 – 50 mm Plastic Corner

One of the design options within the 50 mm plastic corner product family.

When evaluating these products, manufacturers should review the technical drawings and intended installation conditions.

ALUMINUM CORNER CONNECTORS

Aluminum is another material used in the AYS corner connector collection.

The catalogue includes several aluminum configurations, such as:

A0002 – 40-25 mm Aluminum Radius Corner

A radius-style aluminum connector with its own connection geometry.

A0008 – 50 mm Hygienic Aluminum Corner

An aluminum model included in the hygienic corner category.

A0016 – 50-50 mm Aluminum Radius Corner

An aluminum radius connector designed with a different nominal geometry.

WHICH MATERIAL IS BETTER?

There is no universal answer.

Choosing between plastic and aluminum should depend on the actual engineering requirements of the AHU frame.

Manufacturers should evaluate material specifications, connection design, installation requirements and compatibility with the rest of the casing assembly.

Neither material should be selected solely on the assumption that it will perform better in every application.

3. CONSIDER THE GEOMETRY OF THE CORNER CONNECTOR

Material is only one part of the decision.

The physical design of the connector can be equally important.

AHU corner connectors may feature different shapes and construction details, depending on the intended profile and assembly method.

Within the AYS product range, manufacturers can find several design categories.

STANDARD CORNER CONNECTORS

These models provide different connection geometries for AHU frame construction.

Examples include P0002, P0026 and P0027.

RADIUS CORNER CONNECTORS

Radius designs are another option for specific frame configurations.

For example, P0023 – 50-50 mm Plastic Radius Corner and A0016 – 50-50 mm Aluminum Radius Corner are available in the AYS catalogue.

The suitability of these models should be checked against the profile cross-section and technical drawings.

HYGIENIC CORNER CONNECTORS

AYS also offers products identified as hygienic corner designs, including P0011, P0025 and A0008.

These options allow manufacturers to evaluate different connector geometries when planning AHU assemblies with hygiene-related design requirements.

OTHER CONNECTION DESIGNS

The AYS catalogue also includes alternative configurations, such as screw-fixed plastic corners, capped corners and gasketed corner designs.

These product categories demonstrate why connector selection should begin with the required assembly configuration rather than a single preferred model.

4. EVALUATE HYGIENE AND CLEANABILITY REQUIREMENTS

Hygienic AHU applications may require particular attention to internal surfaces, accessibility and cleaning procedures.

In systems where cleanliness is an important design consideration, engineers should evaluate how individual components fit into the complete casing construction.

Relevant considerations include the accessibility of joints, surface geometry and the potential for difficult-to-clean areas.

AYS offers several products within its hygienic corner categories, including:

• P0010 – 40-25 mm Hygienic Plastic Corner
• P0011 – 50 mm Hygienic Plastic Corner
• P0025 – 50-35 mm Hygienic Plastic Corner
• A0008 – 50 mm Hygienic Aluminum Corner

These are different product options that can be reviewed when selecting components for hygiene-focused AHU designs.

However, a hygienic product designation does not, by itself, establish compliance with a particular hygiene standard or certify the performance of a complete air handling unit.

Manufacturers should evaluate the full assembly and applicable project requirements.

5. REVIEW TECHNICAL DRAWINGS BEFORE MAKING A DECISION

One of the most common mistakes in mechanical component selection is relying exclusively on product photographs.

Two corner connectors may look similar while having different dimensions or connection geometries.

Technical drawings provide the information required for a more accurate comparison.

Before approving a component for production, AHU manufacturers should verify:

• Profile dimensions: Does the connector match the intended frame geometry?

• Connection details: Are the insertion features and joining surfaces compatible?

• Assembly method: Does the selected configuration suit the planned installation process?

• Adjacent components: Will the connector fit correctly with panels, profiles and other relevant assembly elements?

• Prototype verification: Has the selected connector been checked in the actual frame assembly?

These checks are especially important when transitioning from prototype development to serial manufacturing.

6. CORNER CONNECTORS AND AHU CASING PERFORMANCE

Corner connectors are part of a larger mechanical assembly.

Their selection should therefore be considered together with the other components of an air handling unit casing.

For example, EN 1886:2025 addresses test methods and classifications for the mechanical performance of AHU casings, including mechanical strength and air leakage.

These are characteristics evaluated at the casing or unit level, not performance values that can automatically be attributed to an individual corner connector.

A complete AHU assembly also involves frame profiles, panels, sealing arrangements and other construction details.

Selecting a connector with the appropriate geometry is one step in the engineering process, but overall casing performance requires separate evaluation and verification.

7. EXPLORE DIFFERENT AYS CORNER CONNECTOR OPTIONS

AYS offers a range of plastic and aluminum corner connectors for air handling unit manufacturers.

Selected plastic options:

• P0002 – 40-25 Plastic Corner
• P0004 – 50-30 mm Plastic Corner
• P0011 – 50 mm Hygienic Plastic Corner
• P0023 – 50-50 mm Plastic Radius Corner
• P0025 – 50-35 mm Hygienic Plastic Corner
• P0026 – 50 mm Plastic Corner

The corresponding product information specifies PA6 with 30% glass-fiber reinforcement for these plastic models.

Selected aluminum options:

• A0002 – 40-25 mm Aluminum Radius Corner
• A0008 – 50 mm Hygienic Aluminum Corner
• A0016 – 50-50 mm Aluminum Radius Corner

These are selected examples rather than the complete AYS corner connector range.

Product dimensions and compatibility should be confirmed using the individual technical drawings.

With multiple material and geometric configurations available, manufacturers can explore connector options according to their own frame construction requirements.

FREQUENTLY ASKED QUESTIONS

What is the main function of an AHU corner connector?

An AHU corner connector is used to join corresponding frame profiles at a corner connection point. Its geometry must be compatible with the selected frame construction.

Are plastic and aluminum corner connectors interchangeable?

Not necessarily. Even when two products have similar nominal dimensions, they may have different shapes, connection details or installation requirements.

Compatibility should always be verified through technical drawings and actual assembly checks.

How do I choose a corner connector for a 50 mm AHU frame?

Start by identifying the exact frame profile geometry.

AYS offers multiple products within its 50 mm-related corner connector range, including standard, radius and hygienic designs.

The correct selection depends on the profile dimensions and connection configuration, not only the 50 mm designation.

What is the difference between standard and hygienic corner connectors?

These are different product design categories.

When selecting a connector for an application with hygiene-related requirements, the engineer should evaluate its geometry as part of the complete casing design, including cleaning access and applicable specifications.

Where can I find technical drawings for AYS corner connectors?

The AYS product catalogue includes individual product pages with dimensional drawings, product codes and material information.

For additional technical information, manufacturers can contact the AYS team.

CONCLUSION: THE RIGHT AHU FRAME STARTS WITH THE RIGHT CONNECTION

Selecting corner connectors for air handling unit frames requires more than choosing a familiar product shape or matching a nominal dimension.

Profile compatibility, material selection, connector geometry and application requirements should all be considered before a component is approved for production.

From standard plastic corners to aluminum radius and hygienic configurations, the AYS catalogue offers a range of options for manufacturers working with different AHU frame designs.

The most effective selection process begins with technical drawings and continues with real assembly verification.

FIND THE RIGHT CORNER CONNECTOR FOR YOUR AHU PROJECT

Explore the AYS Plastic Corner and Aluminum Corner Collections to review available models, dimensions and material specifications.

Whether you are developing a new air handling unit or evaluating components for an existing frame design, the AYS team can assist with product information and technical documentation.

Contact AYS for technical drawings, product enquiries and quotation requests.

Innovative Components, Excellent Performance.