Gravity Louvre Ventilation ABS Plastic 460x460mm Ø400mm UV Resistant GSP 400, Harmann

Quick Facts – Harmann GSP 400 Gravity Louvre

• Brand: Harmann
• Model: GSP 400
• EAN: 5901885909042
• Type: Gravity louvre for ventilation exhaust
• Material: ABS plastic (UV resistant)
• Overall dimensions (A): 460 × 460 mm
• Mounting diameter: Ø 400 mm
• Depth (B): 26 mm
• Inner dimension (C): 364 mm
• Mounting aperture (D): 423 mm
• Mounting: Wall, horizontal
• Function: Backflow prevention (non-return valve principle)

The Harmann GSP 400 is a gravity louvre designed for wall mounting at the outlet of ventilation systems. The blades open under the pressure of the airflow when the ventilation is running and close by gravity when the airflow stops, acting as a non-return valve. This prevents backflow in the ventilation installation, reduces heat losses and protects the ventilation duct against wind, rain, snow and hail.

The louvre is manufactured from ABS plastic, a durable thermoplastic material that combines three properties: acrylonitrile provides chemical resistance and heat stability, butadiene provides toughness and high impact strength, and styrene provides rigidity. The material is UV resistant, which is important for components exposed to direct sunlight in outdoor installations. The overall dimension is 460 × 460 mm, the mounting diameter Ø 400 mm and the depth 26 mm.

The louvre is designed for horizontal mounting. The opening angle of the blades depends on the ventilation system's airflow – at lower flows the blades do not open fully. Incomplete opening is not a fault in the louvre but an indicator of limited airflow in the system.

What is the Harmann GSP 400 gravity louvre and why should you choose it?

The Harmann GSP 400 is a passive gravity louvre that operates without any electrical connection or control. The blades open automatically with the airflow from the ventilation and close by their own weight when the flow ceases. This simple mechanical system is quiet in operation and requires no maintenance beyond cleaning. The ABS plastic is lightweight, chemically resistant and withstands UV exposure without becoming brittle. The louvre acts as a non-return valve that both reduces heat losses and protects against weather. The standard Ø 400 mm size makes it compatible with common ventilation ducts and wall penetrations.

What environments is the Harmann GSP 400 gravity louvre suited to?

The louvre suits wall mounting on residential buildings, offices, warehouses, industrial premises and agricultural buildings at exhaust openings from kitchens, bathrooms, ventilation systems, industrial exhaust ducts and similar installations with a Ø 400 mm connection. The ABS plastic withstands outdoor exposure with direct sunlight, rain and temperature variations. The louvre functions in both dry and humid environments and is easy to clean with water and mild detergent.

Technical Specifications

Suitable for: HVAC installers, property managers, builders, homeowners and ventilation contractors who need passive backflow prevention for exhaust openings.

Industries: HVAC installation, property management, house building, renovation and ventilation contracting.

Frequently Asked Questions (FAQ)

Does the Harmann GSP 400 gravity louvre function as a non-return valve on kitchen or bathroom ventilation exhausts?

Yes, the Harmann GSP 400 gravity louvre functions as a passive non-return valve. The blades open under the pressure of the airflow when the ventilation is running and close by gravity when the flow stops. This prevents backflow in the duct, reduces heat losses and protects against wind, rain and snow from outside. The louvre is designed for horizontal wall mounting with a Ø 400 mm connection.

What dimensions does the Harmann GSP 400 gravity louvre have and which ventilation duct does it fit?

The Harmann GSP 400 has overall dimensions of 460 × 460 mm with a mounting diameter of Ø 400 mm. The depth is 26 mm, the inner dimension 364 mm and the mounting aperture 423 mm. The louvre fits ventilation ducts with a nominal diameter of 400 mm. It is manufactured from UV-resistant ABS plastic and suits outdoor mounting on building exterior walls.

What sets the Harmann GSP 400 gravity louvre apart from the larger GSP 450 model?

The Harmann GSP 400 has overall dimensions of 460 × 460 mm and a mounting diameter of Ø 400 mm, while the GSP 450 has 501 × 501 mm overall dimensions and Ø 450 mm mounting diameter. The GSP 400 fits ventilation ducts with a nominal diameter of 400 mm – one of the most common sizes for residential and commercial ventilation. The GSP 450 is used for higher-capacity systems with Ø 450 mm ducts. Both models share the same construction with UV-resistant ABS plastic, passive gravity operation and backflow prevention via the non-return valve principle.