A Guide to Accurate Fan Selections for Fume Extraction Systems

Download Axair's free guide on accurate fan selections to ensure effective and efficient extraction in fume extraction systems.

At the core of fume extraction systems, when maintaining the required pressure and airflow to extract fumes effectively, the responsibility rests with the industrial fan. This makes correct fan selection one of the most important system specifications.

Axair Fans offer a free downloadable guide on accurate fume fan selections and best practices to ensure effective and efficient extraction in fume extraction systems. This comprehensive resource, written by Axair’s experts in fume fans and air movement for chemical applications, is your roadmap to mastering the process of fan selection in complicated fume extraction systems, ensuring a healthier, safer, and more productive workspace.

One of the most important things you will be asked upon requesting a fume fan selection, is for you to consider if you’ll ever want to speed control the fan, this will determine the voltage, whether single or three phase. From here you will need to provide additional information starting with the below:

1.Airflow

Accurate assessment of the airflow requirements is essential to ensure proper ventilation and fume extract. Factors such as the size of the workspace, the volume and nature of the chemical fumes generated, and the fume hood configuration must be considered to determine the required airflow.

2.Pressure

The fan should be able to generate sufficient static pressure to overcome resistance from ductwork, filters, and other system components. Proper evaluation of the pressure requirements ensures that the fan can maintain the necessary airflow throughout the system.

3.Chemical Compatibility

Chemical compatibility is crucial to avoid corrosion, degradation, or contamination of fan components. The fan materials must be resistant to the chemicals being extracted to ensure durability and long-term performance. Therefore, an analysis of the chemicals present is a must.

4.Noise Levels

Consideration should be given to the noise levels produced by the fan. Selecting a fan with low noise emissions is important to maintain a comfortable and productive working environment, as well as contributing to environmental initiatives and BREEAM assessments.

5.Energy Efficiency

Choosing an energy efficient fan helps to reduce operational costs, scope 2 carbon emissions and environmental impact. Fans with high efficiency motors, variable speed drives and intelligent controls can optimise energy consumption based on the actual fume extraction requirements.

6.Regulation Compliance

Ensure that the selected fan meets relevant industry regulations, standards and guidelines for workplace air quality and fume extraction. Compliance with regulations ensures a safe working environment and avoids regulatory issues. This includes both ATEX UK & EU directives.

7.Control Requirements

on/off, start/stop, interval start/stop, how will the overall system need to operate?

8.Functional Adaptability

Will the system need to change in the future that may increase the system duties?

Best Practices for Accurate Fan Selection

Conduct a comprehensive evaluation of the workspace, including the types and quantities of chemical fumes generated and the spatial layout. This information will help your fan manufacturer to choose a fan that can withstand the chemicals present. If the area has potentially explosive gases present, conduct or contract a hazardous area classification to determine the presence of this gas. This will determine whether an ATEX fan is required. An ATEX gas zone will be given for the area that is used to select a fan - we’ll cover this in more depth shortly.

1 - Engage with Fume Fan Experts Early

•Give as much information as possible to make selection easier.

•Download or request technical documentation.

•Collaborate and consult regularly.

•Learn from experts, and develop your own fume extraction expertise.

•Utilise tools to accurately determine airflow and pressure.

2 - Prioritise Energy Efficient Fans in-line with Objectives

If the application objectives focus on the reduction of operational costs, sustainability, BREEAM, or scope 2 emissions, prioritise the specification of energy efficient fans with advanced control features to optimise energy consumption based on actual demand. In some instances, your fan manufacturer may advise alternative AC fans with inverter drives to ensure better performance, slow start ups or accurate speed control while reducing energy.

Consequences of Incorrect Fan Selection

Inadequate Fume Extraction

If the fume extraction fan does not provide sufficient airflow or static pressure, it may result in inadequate extraction of fumes. This can lead to the dispersion of chemical fumes within the workplace, posing health risks to employees and comprising air quality. Accumulation of chemical fumes in the workspace can lead to respiratory issues, eye irritation, and other health hazards. Chemical fumes can also escape into adjacent areas or contaminate other processes or equipment.

Increased Operational Costs

Inefficient fan operation can lead to increased operational costs. If the fan is oversized or consumes excessive energy, it may result in unnecessary energy expenditure. Conversely, an undersized fan may require additional fans or modifications to the system, increasing installation and maintenance costs, processes or equipment.