Hoods

Extraction Hood

When it comes to maintaining clean air in industrial environments, an effective extraction hood system is essential for capturing and removing light dust, gases, and particles at the source. Gram Clean Air's extraction hoods are engineered to provide reliable, efficient ventilation solutions for a wide range of industrial applications where localized air cleaning is required.

Comprehensive Extraction Hood Solutions

Hoods, designed for the extraction of light dust, gases and particles, form the cornerstone of effective process ventilation systems. Our extraction hood range delivers targeted air cleaning performance over limited work areas, ensuring that contaminants are captured before they can disperse into the broader workspace environment.

The hoods are available in different sizes, and can be combined to cover a larger area, providing flexible solutions that adapt to your specific operational requirements. This modular approach allows facilities to scale their extraction systems efficiently, whether protecting a single workstation or an entire production line.

Gram hoods are suitable for extraction over limited areas, e.g. welding robots, lathes, laser cutters etc., making them ideal for precision manufacturing environments where point-source contamination control is critical. Each hood is engineered to optimize airflow patterns, ensuring maximum capture efficiency while minimizing energy consumption.

Can be made in special dimensions up to 1100x2500mm per hood, accommodating even the most demanding industrial applications where standard sizing may not suffice.

Product Category Overview

Our extraction hood portfolio comprises two primary configurations, each designed to address specific ventilation challenges:

Hood with Edge Extraction Type EM

Highly efficient hood equipped with edge extraction technology that creates a uniform capture zone around the entire perimeter. The hood works like an air carpet all the way around, generating consistent airflow that draws contaminants from all directions. This 360-degree extraction capability ensures comprehensive coverage, even when the contamination source moves within the hood's operational area.

Made standard in powder enamelled steel, the Type EM hood combines durability with corrosion resistance for long-term reliability. Can against additional payment be made in powder enamelled hot-galvanized plate or in stainless steel, providing material options that match your environmental conditions and chemical exposure requirements.

Hood for Lamellas Type EMS

The Type EMS represents a specialized hood module with the option for lamella curtain suspension, designed for applications requiring both extraction and physical containment. This highly efficient hood without edge extraction for lamella fixing in 2- or 3mm, 33% overlap, provides a complete barrier solution while maintaining optimal ventilation performance.

Delivered inclusive suspension system for bolting on lamellas, the Type EMS simplifies installation and ensures proper curtain alignment. The hood equipped with baffle plate for air distribution ensures uniform airflow across the entire hood area, preventing dead zones where contaminants might escape capture.

Materials and Process Applications

Suitable for the extraction of fumes generated during various industrial processes, our extraction hoods excel in environments where traditional ventilation systems prove inadequate. The targeted nature of hood extraction makes them particularly effective for:

• Welding Operations: Capture welding fumes and metal particulates from both manual and robotic welding stations
• Machining Centers: Extract coolant mist and metal chips from lathes, mills, and turning operations
• Laser Cutting: Remove combustion byproducts and vaporized materials from laser processing equipment
• Mixing and Blending: Control dust emissions from powder handling and mixing vessels
• Conveyor Transfer Points: Minimize particulate escape at material discharge locations

The Type EMS hood is specifically designed for extraction and screening of processes, where pin-point extraction is not possible. Dust sorts must be light, so capture velocity of 0.5m/s can be used. Application often in connection with robots, mixing vessels, output areas on conveyor belts and similar operations where the contamination source area is larger than a single point.

Technical Features and Specifications

Construction Quality

Manufactured standard in powder enamelled steel, all Gram extraction hoods deliver industrial-grade durability. The powder coating provides excellent resistance to chemical exposure and mechanical wear, ensuring long service life even in demanding environments. Easy assembly to cover a larger area enables rapid deployment and reconfiguration as production needs evolve.

Mounting and Installation

Equipped with 4 suspension points for mounting from roof ceiling, our hoods integrate seamlessly into existing facility infrastructure. Is available with mountings designed for various ceiling types and load-bearing requirements. Special hoods are available according to measurements and purpose, ensuring that unique facility constraints never compromise air quality.

Modular Expansion Capability

Possibility of bolting together several modules to a larger total extraction surface enables cost-effective system expansion. At bolting the same holes are used for module connection, where otherwise the lamellas are mounted, streamlining the installation process and reducing hardware requirements.

Lamella Integration

For selection of lamellas in 2- og 3mm, 33%, we refer to product group 7. Lamellas are available in 3 standard colours: mat dark green, green and clear, allowing visual integration with facility aesthetics while maintaining functional performance. Delivered exclusive lamellas, the Type EMS hood provides flexibility in curtain specification based on application requirements.

System Integration and Performance

Effective extraction hood performance depends on proper integration with your overall ventilation system. The airflow generated by the hood must be matched with appropriate filter capacity and fan performance to ensure captured contaminants are effectively removed and cleaned. Our engineering team can assist in sizing the complete system, from hood selection through filter specification and exhaust requirements.

The baffle plate design incorporated in our hoods ensures even air distribution across the capture area, maximizing efficiency while minimizing the required airflow volume. This optimization reduces energy consumption and allows for smaller, more economical filter and fan sizing.

Partner with Gram Clean Air

Selecting the right extraction hood configuration requires careful consideration of your specific processes, contaminant characteristics, and facility constraints. Our technical specialists bring decades of experience in industrial ventilation design and can guide you through the selection process, ensuring optimal performance and compliance with air quality regulations.

Contact Gram Clean Air today to discuss your extraction hood requirements. We'll help you design a system that protects your workers, maintains production quality, and delivers reliable, long-term performance.

Frequently Asked Questions About Extraction Hoods

To help you make informed decisions about your industrial ventilation needs, we've compiled answers to the most common questions our clients ask about extraction hood systems. Whether you're planning a new installation or optimizing an existing system, these insights will guide you through the key considerations for effective fume and dust extraction.

What is an extraction hood and how does it work?

An extraction hood is a localized ventilation system designed to capture and remove airborne contaminants at the source. The hood creates a controlled airflow pattern that draws fumes, dust, and particulates away from the work area before they can disperse into the broader workspace. When positioned correctly over equipment such as welding robots, lathes, or laser cutters, the extraction hood captures emissions directly at the point of generation. The contaminated air is then directed through a filtration system where particles and fumes are removed before the cleaned air is either recirculated or exhausted. The effectiveness of an extraction hood depends on proper sizing, positioning, and sufficient airflow velocity to overcome the momentum of the generated contaminants.

What types of industrial processes are Gram extraction hoods suitable for?

Gram extraction hoods are specifically engineered for extraction over limited, defined areas where fume generation is concentrated. They excel in applications including welding robot cells, where metal fumes and particulates require immediate capture; CNC lathes and machining centers, where coolant mist and metal dust are produced; and laser cutting operations, where vaporized materials create hazardous fumes. These hoods are particularly effective for fume extraction in processes that generate consistent emission patterns from a fixed location. The compact design allows for targeted ventilation without requiring whole-room air changes, making them an energy-efficient solution for point-source contamination control. Each hood can be configured with appropriate filter media to address the specific contaminants generated by your process.

How do I determine the correct airflow capacity for my extraction hood system?

Determining the proper airflow capacity requires analyzing several critical factors specific to your operation. First, consider the size of the hood opening and the distance from the contamination source—larger openings and greater distances require higher airflow volumes to maintain adequate capture velocity. Second, evaluate the nature of the fumes being extracted: heavier particles and thermally buoyant fumes behave differently and affect system requirements. For welding applications, we typically recommend minimum face velocities of 0.5-1.0 m/s at the hood opening, while laser cutting may require higher velocities depending on material composition. The filter type and loading also impact system performance, as resistance increases over the filter's service life. Gram Clean Air provides technical consultation to calculate the precise airflow requirements for your specific application, ensuring your extraction hood and ventilation system deliver optimal performance while maintaining energy efficiency. Proper sizing prevents both under-extraction, which allows contaminant escape, and over-extraction, which wastes energy and can disrupt the process itself.

Can extraction hoods be integrated into existing ventilation systems?

Yes, Gram extraction hoods are designed with integration flexibility to accommodate both new installations and retrofits into existing ventilation infrastructure. When integrating into an established system, several technical considerations must be addressed. The existing ductwork capacity, fan performance curve, and filter housing must be evaluated to ensure they can handle the additional airflow requirements without compromising system balance. Static pressure calculations are essential to verify that the existing fan can overcome the added resistance of the new hood and associated ductwork. In many cases, extraction hoods can share a common filtration system with other extraction points, provided the contaminants are compatible and the system is properly balanced with dampers or variable frequency drives. Our engineering team can assess your current ventilation system's capacity and recommend whether integration is feasible or if a standalone extraction hood system with dedicated filtration would be more appropriate for your application.

What maintenance is required for extraction hood filter systems?

Regular maintenance of your extraction hood filter system is essential for sustained performance and energy efficiency. The primary maintenance task involves monitoring filter differential pressure—the pressure drop across the filter media—which indicates when filters require replacement. Most Gram systems include pressure gauges or electronic monitoring to track this metric. As filters load with captured particulates and fumes, airflow resistance increases, requiring more fan energy and eventually reducing capture efficiency. Replacement intervals vary significantly based on process intensity, operating hours, and contaminant type; welding fumes may require monthly filter changes in high-volume operations, while lighter-duty applications might extend to quarterly intervals. Beyond filter replacement, quarterly inspections should include checking hood positioning and integrity, verifying ductwork connections for air leaks, examining fan belt tension and bearing condition, and cleaning any accessible surfaces where buildup occurs. Maintaining proper system airflow through timely filter replacement not only ensures effective fume extraction but also prevents excessive energy consumption and potential motor failure from prolonged operation against high resistance.

How close does an extraction hood need to be positioned to the source?

Hood positioning is critical to extraction efficiency, and the relationship between distance and required airflow follows the inverse square law—doubling the distance requires approximately four times the airflow to maintain the same capture velocity. For optimal performance, Gram extraction hoods should be positioned as close as practically possible to the fume source while allowing adequate clearance for equipment operation and operator access. As a general guideline, the hood should be placed within one hood diameter of the contamination source for processes without significant thermal rise. For welding applications, positioning the hood 300-600mm from the weld point typically provides effective capture without interfering with the process. Laser cutting and similar operations may allow slightly greater distances if the fumes have upward thermal momentum. The hood should also be oriented to work with, rather than against, the natural movement of contaminants—for example, positioning above thermally buoyant welding fumes rather than attempting to pull them downward. Our technical team can provide specific positioning recommendations based on your equipment layout, process parameters, and facility constraints to maximize extraction efficiency.

Ready to improve your facility's air quality? Contact Gram Clean Air today to discuss your specific extraction hood requirements with our ventilation specialists. We'll help you design a solution that delivers clean air, regulatory compliance, and long-term value.