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In many industrial environments, safety is not simply about maintaining comfort or ensuring operational efficiency. Facilities that handle gases, vapours or combustible substances face an additional challenge: the risk of explosive atmospheres. For consultants, contractors and facility operators, this creates a difficult balancing act. How can a ventilation solution be designed and operated to support the process while also meeting the requirements for explosion protection? And who is responsible for determining what level of protection is actually required?
This is where ATEX becomes an essential part of the discussion, William Lawrance, Senior Product Manager at Swegon, will explain.
The European ATEX Directive addresses the safety of equipment and systems intended for use in potentially explosive atmospheres. Within air handling applications, ATEX requirements become relevant whenever there is a risk that the ventilation system may be exposed to gases, vapours or dust that could cause an explosion.
One important aspect is that the environment inside the air handling unit and the environment surrounding it may need to be assessed separately. Air handling units are never completely airtight, and maintenance activities can expose internal components to external atmospheres. As a result, both the inside and the outside of the unit need to be considered when evaluating explosion protection requirements.
The required protection level depends on the classification of the hazardous area. In general terms, areas where explosive atmospheres are expected more frequently require a higher level of protection than areas where such conditions occur only rarely.
Designing air handling units for ATEX applications
There is no general solution for air handling units for ATEX applications. The unit is a part of a system designed for a specific ATEX application with its own set of requirements and must be correctly configured with appropriate components.
The system designer and installer play a crucial role in defining the hazardous zones, identifying the gas group and determining the required temperature classification. These requirements must be specified before any equipment can be selected correctly.
The manufacturer can provide equipment designed for a particular category and operating condition but cannot determine the explosion classification of the installation itself. The overall responsibility for explosion protection ultimately lies with those designing, installing and operating the complete solution.
This highlights an important principle: ATEX compliance should always be approached as a system-level consideration rather than a product-level decision.
Key considerations when specifying ATEX air handling systems
When designing ventilation solution for hazardous environments, several factors should be considered from the outset.
Earthing and prevention of static electricity
Metallic components should be connected to the protective earthing system to prevent the build-up of static electricity. Non-conductive materials and large plastic surfaces should be minimised wherever possible, as static discharge can become a potential ignition source.
Selection of electrical components
Motors, switches, lighting and other electrical components must be suitable for the required protection category and operating environment. Particular attention should be paid to the relevant gas group and temperature classification.
Fan design
Fans are critical components in ATEX applications. The risk of friction, vibration and the generation of hot spots must be carefully managed. Direct-driven fans often offer advantages because they eliminate belts that could otherwise introduce additional ignition risks.
Dust control
Dust accumulation can increase both fire and explosion risks. Effective filtration, combined with regular cleaning and maintenance, helps minimise the likelihood of hazardous deposits forming within the system.
Maintenance and operation
Even a correctly specified system can present risks if maintenance is not carried out properly. Inspection, servicing and repair work should only be performed by trained personnel using appropriate procedures and equipment. In some situations, systems may need to be purged with fresh air before maintenance activities can begin.
Looking beyond compliance
ATEX projects are often viewed primarily through the lens of regulatory compliance. However, the real objective is to create an environment where safety, reliability and operational performance work together.
Achieving this requires close collaboration between planners, contractors, operators and manufacturers. The earlier explosion protection considerations are integrated into the design process, the easier it becomes to develop a solution that balances safety requirements with practical operational needs.
From requirements to practical solutions
Understanding ATEX requirements is one thing. Turning those requirements into a practical ventilation solution is another.
In many projects, the challenge is not simply identifying the hazardous zone or defining the required protection category. The real challenge lies in combining safety requirements with airflow performance, installation constraints, energy efficiency and long-term maintainability. This is why flexibility is often a key success factor in ATEX applications.
No two facilities are exactly alike. The processes, risk assessments and operating conditions can vary significantly, meaning ventilation systems need to be adapted to the specific demands of each project rather than fitted into a standard template.
This is GRAND
At Swegon, we work closely with consultants, contractors and end users to help ensure that ventilation solutions support the overall explosion protection strategy while also meeting the project's operational requirements.
One example is the modular GRAND air handling unit, which can be configured for use in potentially explosive environments. It can be adapted for operation in hazardous areas up to category Ex II 2G IIB+H₂ T4, both indoors and outdoors. The systems are designed for Zone 1 applications, where an explosive gas atmosphere may occur regularly. The units are developed to maintain a high level of safety even in the event of foreseeable faults or malfunctions, supporting compliance with the applicable ATEX requirements.
The modular design also allows the solution to be configured according to the specific needs of the project, helping consultants and building owners balance safety, performance and operational requirements without unnecessary compromise.
Safety starts with the right approach
ATEX is not simply about selecting certified equipment. It is about understanding the risks, defining the correct requirements and ensuring that every part of the system contributes to a safe and reliable installation. When explosion protection is considered early in the design process and supported by solutions that can be adapted to the application, it becomes easier to create environments that are both safe and efficient.
That is ultimately the goal: helping customers move from compliance requirements to practical, dependable solutions that support their long-term success. Contact us for more information.
