ATEX Fans: The Complete Guide

In environments where flammable gases, vapours or dust may be present in the air, ventilation is not simply a matter of air circulation. A spark at the wrong moment, from mechanical contact between moving and stationary parts, an overheated motor or an electrostatic discharge, can cause an explosion. ATEX fans are designed to eliminate that risk.

In this guide, we explain exactly what ATEX entails, how the system of zones, categories and temperature classes works, which standards apply to fans, and how to make the right choice for your application. Whether you are an installer, engineer, facility manager or buyer: after reading this guide, you will know what you need.

What is ATEX?

ATEX stands for ATmosphères EXplosibles, French for explosive atmospheres. It is a European directive (2014/34/EU, also known as ATEX 114) that sets requirements for equipment intended for use in environments where an explosive atmosphere may arise. In addition, ATEX 153 (Directive 1999/92/EC) applies to employers: they are required to classify the workplace into zones and select appropriate equipment.

Every electrical or mechanical installation in an ATEX zone, including fans, must comply with the requirements of the directive. A fan that is not certified for this purpose is legally prohibited in an explosive environment and poses a direct safety risk.

How does ATEX zoning work?

The likelihood of an explosive atmosphere determines the zone in which a location is classified. For gases and vapours, zones 0, 1 and 2 apply; for combustible dust, zones 20, 21 and 22. The lower the number, the more frequently the explosive atmosphere is present, and the more stringent the requirements for equipment.

Zone 0: Explosive gas atmosphere present continuously (e.g. inside a storage tank)
Zone 1: Explosive gas atmosphere occurs during normal operation
Zone 2: Explosive gas atmosphere only under abnormal conditions
Zone 20: Explosive dust cloud present continuously
Zone 21: Dust cloud occurs periodically
Zone 22: Dust cloud only under abnormal conditions

ATEX equipment categories

Based on the zone, the required equipment category is determined. Category 1 offers the highest level of protection and is required for the most hazardous zones (0/20). Category 2 is intended for zones 1/21, and Category 3 for zones 2/22.

Temperature classes (T-classes)

In addition to the zone and category, the T-class plays a crucial role. This class indicates the maximum allowable surface temperature of a device. That temperature must always remain below the auto-ignition temperature of the gas or dust present. T1 permits up to 450°C; T6 a maximum of 85°C. The higher the T-number, the more stringent the requirement.

The standard for ATEX fans: EN 14986

Fans are a special category with specific ignition risks: mechanical risks such as friction and abrasive contact, electrostatic charge from coating layers, and, in the case of axial fans, where the motor is located within the airstream, electrical spark risks within the airflow itself. The EN 14986 standard specifically describes the construction requirements for fans in explosive atmospheres: material pairings of rotating and stationary parts, clearance requirements, and permitted coatings.

ATEX vs. IECEx: Europe versus the rest of the world

ATEX applies within the EU. Outside Europe, in Australia, the Middle East, Asia and South America, the IECEx system applies. For international projects, it is advisable to select fans that are certified under both ATEX and IECEx.

In which sectors are ATEX fans required?

ATEX certification is mandatory in all environments where explosive hazardous zones have been formally designated. This applies in particular to:

Chemical and petrochemical industry
Food industry (flour, sugar, grain — combustible dust)
Tunnels, metro systems and certain car parks, but only where an ATEX zone has been formally established, which is generally not the case in standard car parks
Pharmaceutical production
Offshore and mining
Biogas installations and water treatment

More than 80% of all ATEX zones worldwide fall within zone 2 or 22 — the zones with the lowest risk. This means that Category 3 equipment is sufficient in most cases, and that selection is simpler than many people assume.

Ventinet / Ventispecial: ATEX fans from the manufacturer

Ventinet supplies industrial fans for virtually every application, including a complete range of ATEX-certified fans under the Ventinet and Ventispecial brands. We supply installers and OEM customers worldwide and are happy to advise on the right specification for your project.

Explore our full range of ATEX fans, or contact us directly.

Want to know immediately which ATEX fan suits your situation? Use our step-by-step selection guide.