ISO 5802:2001

Overview

ISO 5802:2001 - Industrial fans - Performance testing in situ is an international standard that specifies procedures, measurements and reporting for determining the performance of industrial fans installed in their actual operating circuits (on-site or in situ). The standard defines terms and symbols, the quantities to be measured, recommended test conditions, instrumentation and detailed methods for determining fan pressure, flow rate and power, together with uncertainty analysis and several normative annexes.

Keywords: ISO 5802:2001, industrial fans, performance testing, in situ, fan testing, flow measurement, stagnation pressure, velocity-area methods, instrumentation, uncertainty.

Key topics and requirements

• Scope and definitions: Precise definitions for fan components (impeller, casing), flow and temperature terms, and the convention that fan pressure is the difference between stagnation pressure at inlet and outlet.
• Measurement quantities: Time‑averaged values for pressure, velocity, temperature, density and rotational speed.
• Test procedures and conditions: Guidance on selecting test points, handling fans with adjustment devices, and when system throttling is used or unavailable.
• Instrumentation: Detailed requirements for pressure, velocity (including velocity‑area methods), temperature and density measurements and for rotational speed and power determination (see Clauses 6 and 9).
• Pressure measurement: Location of inlet/outlet measurement planes and methods for determining fan pressure using stagnation pressure.
• Flow rate determination: Choice of measuring method and section (velocity‑area, differential pressure devices), and recommended positioning of measurement points (log‑Tchebycheff or log‑linear spacing vs. arithmetic spacing).
• Power measurement and losses: Definitions of performance characteristics relating to motor/impeller power, transmission losses and acceptable measuring practices.
• Uncertainty: Analysis of measurement uncertainty and factors affecting in situ test accuracy (installation or “system‑effect” is emphasized).
• Normative annexes: Annexes A–E cover exploration line positioning, minimum straight lengths, loss allowances for ducts, and anemometer calibration.

Practical applications and users

ISO 5802:2001 is used for:

• On-site performance verification and acceptance testing after installation or commissioning
• Troubleshooting and performance audits (HVAC, industrial ventilation, power plants, process industries)
• Retrofit evaluation and energy efficiency assessments
• QA testing by fan manufacturers, test laboratories and third‑party inspectors

Typical users:

• Mechanical and HVAC engineers
• Test laboratories and commissioning teams
• Fan manufacturers and OEMs
• Plant maintenance and reliability engineers
• Consultants performing compliance or energy audits

Related standards

• ISO 5801:1997 - Industrial fans - Performance testing using standardized airways
• ISO 5167-1 - Flow measurement by differential pressure devices
• IEC 60034-1 - Rotating electrical machines - Rating and performance
• IEC 60051-8 - Electrical measuring instruments - Accessories

ISO 5802:2001 supports accurate, repeatable in situ fan testing by specifying measurement methods, instrumentation and uncertainty considerations - essential for reliable performance verification and energy optimization of industrial ventilation systems.