ISO 19659-3:2022

Overview

ISO 19659-3:2022 - "Railway applications - Heating, ventilation and air conditioning systems for rolling stock - Part 3: Energy efficiency" provides a standardized methodology for calculating, measuring and verifying the energy consumption of HVAC systems in passenger rolling stock. The standard focuses on passenger-area HVAC (driver’s cab systems are excluded) and links energy assessment to the thermal comfort requirements defined in ISO 19659-2. It supports comparable, repeatable evaluation of HVAC energy use across different train types and operating conditions.

Key topics and technical requirements

• Scope and applicability: Covers passenger-area HVAC systems for vehicle categories defined in ISO 19659-2:
  • Category 1: main line, intercity, long distance, high speed
  • Category 2: suburban, commuter, regional
  • Category 3: urban, LRV, tram, metro/subway
• Train modes: Defines operational modes relevant to energy assessment:
  • TISM (Train in-service mode)
  • TRSM (Train ready for service mode)
  • PCM (Pre-conditioning mode)
  • PM (Parking mode)
• Assessment methods:
  • Simulation and calculation: Use steady-state operational point matrices to represent annual climatic and operational conditions; calculate total annual energy consumption and efficiency.
  • Measurement and verification: Provides rules for in-service measurement and validation of simulation results.
  • Post-processing and documentation: Specifies required documentation and reporting for transparency and repeatability.
• Climatic and operational boundary conditions:
  • Operational point matrix (exterior temperature, relative humidity, passenger load, equivalent solar load) defined at zero train speed.
  • Weather data analysis procedures to select representative conditions for a region.
• Principles: Recommends steady-state operational points over long-term in-service monitoring to improve repeatability and reduce testing time and cost.

Practical applications and who uses it

ISO 19659-3 is practical for:

• Rolling stock designers and HVAC suppliers - to size systems and compare energy-efficient concepts.
• Rail operators and transit authorities - for procurement specifications, energy budgeting and lifecycle cost assessments.
• Test laboratories and certification bodies - to verify claimed HVAC energy performance.
• System integrators and consultants - to model annual HVAC energy use, evaluate retrofit options and quantify environmental benefits. Benefits include comparable energy consumption metrics, support for energy-saving design decisions, and alignment with thermal comfort standards.

Related standards

• ISO 19659-1 - Terms and definitions for railway HVAC systems
• ISO 19659-2 - Thermal comfort requirements (normative reference used for energy assessment)

Keywords: ISO 19659-3, HVAC energy efficiency, railway HVAC, rolling stock, energy consumption, thermal comfort, operational point matrix, train modes, simulation, verification.