Industrial fans are vital tools for many sectors, with applications ranging from cooling systems to air quality control. If you own or are responsible for the operation of an industrial fan system, understanding volume air and air pressure is crucial to help ensure your fans operate at optimal performance.

In this blog, we will explore the fundamentals of volume air and air pressure, their importance in industrial fan systems, and how to optimise them for better performance.

Understanding volume air and air pressure for industrial fan systems

What is the difference between volume air and air pressure?

Volume air refers to the amount of air moved by a fan in a given time, while air pressure measures the force used to move the air. These two parameters are interdependent and can significantly affect the efficiency of industrial fans.

What do I need to know?

When discussing your industrial fan requirements with an industrial fan manufacturer, you will need to have some key information to help direct the recommendation from the engineer. These include:

  • The volume of air needed for the application and the air temperature.
  • The pressure required by the equipment installed and ducting for the fan to be designed to move the air to the required point. You must also inform the fan company if the fan needs to be on ‘suction’ or ‘blowing’ as this can make a big difference if the pressure is high.

What units are used to express volume air and air pressure?

Volume air and air pressure, in industrial fan applications, are usually measured in the following units:

Volume air

Cubic Feet Per Minute (CFM). Other units that may also be used include Cubic Meters Per Hour (m³/h) and Cubic Feet Per Second (CFS), depending on the application.

Air Pressure

Pressures are expressed in units such as mm, SWG, Mbar or Pa as well as SWG.


How can we calculate volume air?

Volume Air = Air Velocity × Cross-sectional Area

It’s important to consider the conditions under which the calculation is being made, such as temperature and pressure, as these factors can affect the density of the air. In some cases, you may need to apply correction factors or consider additional variables to obtain more accurate results.

How can we calculate fan air pressure?

In order to calculate fan air pressure, you need to know some information about the fan’s performance, including the airflow rate and the resistance encountered by the air in the system. Remember that fan air pressure can also be influenced by factors such as fan speed, impeller design and system characteristics. For more accurate calculations, consulting the fan manufacturer’s specifications or using specialised performance analysis tools is recommended.

How do you determine if your industrial fan is operating at the right pressure?

Reference the fan specifications

Consult the manufacturer’s specifications or documentation for the fan. Look for the recommended or required operating pressure range for the specific fan model. The manufacturer’s guidelines will provide valuable information on the acceptable pressure range for optimal performance.

Measure the system pressure

Use pressure measuring instruments to measure the air pressure in the system where the fan is operating. Ensure that the pressure measuring device is suitable for the expected pressure range. Compare the measured pressure with the recommended or required operating pressure range from the fan specifications. If the measured pressure falls within the specified range, the fan is operating at the right pressure.

Consider system requirements

In addition to the fan specifications, consider the specific requirements of your system or application. Different industrial processes or HVAC systems may have their own unique pressure requirements. Verify that the measured pressure aligns with the needs of your system to ensure proper operation and performance.

Monitor and adjust as needed

Continuously monitor the fan performance and system pressure over time. If you observe any deviations or issues, it may indicate a problem with the fan or the system. If necessary, consult with an expert or the fan manufacturer to troubleshoot and make adjustments to maintain the appropriate operating pressure.

Regular maintenance, inspection, and calibration of pressure measurement equipment are important to ensure accurate readings and optimal fan performance. When in doubt, it is advisable to consult with a qualified professional or seek assistance from the fan manufacturer for guidance on proper pressure operation.

How often should I have an industrial fan serviced?

The frequency of servicing an industrial fan is dependent on a number of factors – the type of fan, operating conditions and the manufacturer’s recommendations. It’s important to note that the specific servicing needs of an industrial fan may vary depending on factors like fan type (centrifugal, axial etc.), motor type, operating environment (cleanroom, hazardous location), and regulatory requirements. Consulting with the fan manufacturer or a qualified technician can provide more tailored guidance for your specific fan and application.

Will an industrial fan service identify if my fan is not running efficiently?

Yes, an industrial fan service can help identify if your fan is not running efficiently. During a service, a qualified technician can perform various diagnostic tests and inspections to assess the fan’s performance. Here are some ways a fan service can identify efficiency issues:

Performance measurements

The technician may measure and compare the actual airflow rate and air pressure generated by the fan with the expected or specified values. Any significant deviations can indicate a loss of efficiency.

Power consumption analysis

By measuring the electrical power consumption of the fan, the technician can assess if the fan is operating within its expected power efficiency range. Higher-than-normal power consumption may suggest inefficiencies or mechanical issues.

Vibration analysis

Excessive vibration in the fan assembly can indicate imbalances, misalignment, or worn components, all of which can affect the fan’s efficiency. Vibration analysis can help pinpoint potential issues and recommend corrective measures.

Inspection of components

The technician will inspect various components of the fan, such as the impeller, motor, bearings, belts, and drive system. Any signs of wear, damage, or improper assembly can contribute to decreased efficiency.

Airflow distribution analysis

The service technician may assess the distribution of airflow within the system to ensure that the fan is providing adequate ventilation or cooling to the desired areas. Uneven or insufficient airflow can indicate inefficiencies or improper fan placement.

Ductwork evaluation

The technician may examine the ductwork and system design to check for any restrictions, leaks, or improper configuration that could impede the fan’s performance. Optimizing the ductwork can help improve overall efficiency.

Read our previous blog about ensuring your industrial fan is running efficiently here.

How can Industrial Fan Services Ltd help?

Regular servicing and maintenance of industrial fans is a crucial part of minimising energy consumption and maximizing productivity. Our engineers will attend your site to establish your exact requirements, ensure that our industrial fans will be suitable for the job and determine any bespoke design modifications required to make sure the fan is operating at its optimal efficiency level. We will test the existing fans already installed on site to determine the exact duties required for a replacement unit(s). Where possible, we will supply industrial fans to the exact dimensions in order to save on costly duct modifications. Our team can also help extend the efficiency and lifespan of your machinery through creating a proactive maintenance programme including regular vibration and machine condition monitoring.

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