ISO 13348 Industrial Fans - Tolerances, Conversion Methods and Technical Data Presentation

The standard “ISO 13348 Industrial fans - Tolerances, conversion methods and presentation of technical data” developed by the International Organization for Standardization (ISO) specifies the performance tolerances and technical data presentation of all types of industrial fans. However, this standard does not apply to fans designed solely for low volume air circulation, such as those used for household or similar purposes (ceiling and table fans, extractor fans). For jet fans, the standard ISO 13350 Fans - Performance testing of jet fans” applies.

The upper limit of fan work per unit mass is normally 25 kJ kg ⁻¹ , which corresponds to a fan pressure increase of approximately 30 kPa for an average fan density of 1,2 kg m ⁻³ . Higher values require agreement between the supplier and the user.

This international standard covers the four installation categories defined in the ISO 5801 standard:

A free entry, free exit
B free input, channeled output
C channel inlet, free outlet
D channel input, channel output

The performance of a fan can vary significantly depending on the installation category it operates in. Therefore, these categories form an important part of the definition of the fan's technical data presentation.

The international acceptance of four installation categories provides the end user and system designer with the opportunity to conclude a contract based on the most appropriate fan category. Accordingly, the probability of the fan delivering the agreed performance without compromise or trade-off increases.

For the purposes of this standard, the following terms and definitions apply:

An industrial fan is a fan other than one used for household or similar purposes, such as air circulation, air conditioning, etc. According to this standard and other industrial fan standards, a household fan is defined as having a single-phase motor operating at a maximum of 250 Volts and 16 A.
A mass-produced fan (catalog fan) is one whose detailed performances are widely available in a catalogue (electronic or printed) and is often produced in significant quantities and available in short deliveries.
The mean stagnation pressure at a section is the sum of the conventional dynamic pressure and the mean absolute pressure corrected by the Mach factor at the section. The mean stagnation pressure can be calculated by the formula given in the standard.
The mean total pressure at a section is the sum of the conventional dynamic pressure and the mean gauge pressure corrected by the Mach factor at the section.
The characteristic error is the flow rate variation produced along the actual system characteristic with the maximum fan performance deviation allowed by the selected tolerance rating. The characteristic error is a function of the tolerance rating, the allowable measurement uncertainty, the shape of the fan (local slope) and the actual system characteristics. The ISO 5801 standard applies to the actual system characteristics.
The fan dynamic pressure at the outlet is the conventional dynamic pressure at the fan outlet calculated from the mass flow rate, the average gas density at the outlet, and the fan outlet area.

Performance tolerances for custom-designed fans and mass-produced non-certified fans are as follows:

Volume flow rate, fan inlet speed or mass flow rate
Total pressure increase between fan inlet and outlet or static pressure increase in a given discharge area
Distribution of total pressure losses in the system between the inlet and outlet sides of the fan
Absolute pressure at fan inlet
Density of the process fluid at the fan inlet.
Important for fan performance are the temperature of the gas processed at the fan inlet for normal operation and the maximum and minimum temperatures for which the fan will be designed.
Dust, mist or vapour content of the gas at the fan inlet for normal operation, their properties and maximum contents. Information on whether the dust, mist or vapour is flammable, toxic, aggressive or sticky.
The maximum permissible A-weighted sound power level in A-weighted decibels, as specified in the ISO 13347-1 standard.
Maximum permissible mechanical vibration levels in service as specified in the ISO 14694 standard
System characteristics if necessary
Design speed cycles (i.e. the number of speed cycles per 24 hours, the speed range if variable speed, plus the total number of starts-stops for which the fan will be designed)
Other characteristics (e.g. preferred rotation speed, control type and range, inlet and outlet direction, propeller rotation, as viewed from the driver)

The degree of tolerance is specified in accordance with the requirements specified in this standard.

A supplier may only supply a fan for a specific application after the customer has provided him with all the information necessary to complete the order. This should occur before a quotation is prepared or at the latest before a sales agreement is reached. Such information should include details regarding the fan design, arrangement, construction, materials and scope of supply and should be based on the customer's own calculations, measurements and experience in this field.

Our organization has a strong staff that closely follows the developments in the world in the field of science and technology and constantly improves itself. Among the numerous test, measurement, analysis and evaluation studies provided for businesses in various sectors, there are also test services in accordance with the "ISO 13348 Industrial fans - Tolerances, conversion methods and technical data presentation" standard.