High-Level Air Distribution Engineering with LYNX Linear Jet Diffusers

Located in Riyadh, Jawharat Riyadh Mall is a major large-scale retail and lifestyle development combining luxury retail, dining, entertainment and leisure functions within approximately 625,000 m² of built area.

The development features exceptionally large internal volumes, including corridors reaching approximately 30 metres in width, ceiling heights of up to 27 metres, and a landmark 38,000 m² skylight.

These architectural characteristics created a demanding HVAC air distribution challenge: conditioned air had to be delivered effectively from very high installation levels to the occupied zones below.

Gerhman supported the project from the air distribution design and product-selection stage, developing the main air distribution concept around the GERHMAN LYNX Linear Jet Diffuser.

Approximately 2,000 LYNX units were incorporated into the project as one of the principal air distribution elements of the mall.

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The Engineering Challenge: Air Distribution from 27 Metres

Conventional ceiling diffusers become increasingly difficult to apply as installation height increases.

At heights approaching 27 metres, the engineering objective is not simply to introduce conditioned air into the space. The supply jet must maintain sufficient momentum, direction and penetration to influence the occupied zone while avoiding uncontrolled short-circuiting or ineffective distribution at high level.

The large skylight introduces another important thermal variable. Solar radiation and elevated temperatures near the roof can create significant vertical temperature gradients, particularly during cooling operation.

The air distribution design therefore had to consider:

Installation Height · Airflow Rate · Discharge Velocity · Jet Momentum · Throw Distance · Discharge Angle · Cooling / Heating Conditions · Occupied-Zone Requirements

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LYNX Linear Jet Diffuser

The main air distribution system was designed around the GERHMAN LYNX Linear Jet Diffuser, developed for applications requiring controlled, directional and long-distance air delivery.

Unlike conventional fixed-pattern air terminals, LYNX allows the supply-air direction to be adjusted according to the geometry and operating requirements of the space.

This was particularly important at Jawharat Riyadh, where the combination of high ceilings, wide circulation areas and large open volumes required substantial air-jet penetration.

The linear configuration also enabled the air distribution equipment to be integrated continuously into the architectural ceiling concept without introducing large conventional terminal units into the visual field.

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High-Ceiling Airflow Engineering

Gerhman supported the design team with engineering calculations and product-selection studies to determine the appropriate LYNX configurations for different areas of the mall.

The selection process considered the relationship between:

Airflow Rate + Discharge Velocity + Throw Distance + Discharge Angle + Installation Height

The objective was to maintain sufficient jet momentum from the high-level supply position while delivering conditioned air effectively toward the required zones.

Different discharge configurations could therefore be evaluated according to installation height, architectural geometry and thermal operating condition.

This approach was especially important because high-ceiling air distribution cannot be designed solely according to air changes per hour. The trajectory and remaining velocity of the supply jet are fundamental to the performance of the occupied zone.

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Cooling, Heating & Vertical Temperature Effects

The significant height of the mall creates different airflow behaviour under cooling and heating conditions.

During cooling, the density difference between supply and room air assists downward movement, while the diffuser geometry and discharge angle determine the trajectory of the jet.

Heating represents the opposite challenge: warmer supply air naturally tends to rise, making sufficient downward momentum and appropriate discharge direction increasingly important.

The large skylight can further influence the thermal stratification within the upper sections of the building.

For this reason, LYNX selections were evaluated according to the actual thermal operating conditions and required air trajectory, rather than relying on a single fixed discharge configuration.

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Architecture Meets Airflow Engineering

Jawharat Riyadh demonstrates how air distribution becomes an integral part of architectural engineering when building dimensions move beyond conventional HVAC applications.

Nearly 2,000 GERHMAN LYNX Linear Jet Diffusers were incorporated into the development, combining:

Long-Distance Air Delivery
Directional Airflow Control
High-Level Installation Capability
Architectural Linear Integration
Cooling & Heating Airflow Performance

Gerhman’s involvement from the design stage allowed the diffuser configuration to be developed around the actual geometry and operating requirements of the mall.

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Engineering Outcome

The scale and architecture of Jawharat Riyadh required an air distribution strategy specifically developed for large-volume, high-ceiling environments.

Through engineering calculations, product selection and application support, Gerhman developed the main air distribution concept using LYNX Linear Jet Diffusers, enabling controlled directional airflow from installation heights reaching approximately 27 metres.

With approximately 2,000 LYNX units incorporated into the project, the solution represents one of Gerhman’s significant large-scale applications of linear jet air distribution technology.

The project demonstrates a fundamental principle of high-ceiling HVAC design:

In large-volume spaces, effective air distribution is determined not only by airflow quantity, but by the momentum, direction and penetration of the supply air jet.

Project Highlights

Project: Jawharat Riyadh Mall
Location: Riyadh, Saudi Arabia
Project Type: Retail / Lifestyle / Entertainment
Total Area: Approx. 625,000 m²
Maximum Ceiling Height: Approx. 27 m
Major Skylight Area: Approx. 38,000 m²
Corridor Width: Up to Approx. 30 m
Associated Office Development: Approx. 65,000 m²
Gerhman Product: LYNX Linear Jet Diffuser
Quantity: Approx. 2,000 Units
Air Distribution Concept: High-Level · Long-Throw · Directional Linear Jet Air Distribution
Gerhman Scope: Air Distribution Design Support · Engineering Calculations · Product Selection · Airflow Optimization · Application Engineering