ISO 19659-2:2020

Overview

ISO 19659-2:2020 - "Railway applications - Heating, ventilation and air conditioning systems for rolling stock - Part 2: Thermal comfort" defines a general approach to achieving thermal comfort in passenger compartments and saloons of railway vehicles (single-level and double-decker) used for main line, regional/suburban and urban public transport. The standard describes how to specify conditions, target performance values and measurement methods for compartments and local annexes. It does not apply to the driver’s cab.

Key Topics

• Vehicle categories: classification of passenger vehicles (e.g., main line, regional, urban) to set appropriate comfort targets.
• Design conditions: exterior and interior design parameters including temperature, relative humidity, solar load, altitude and train speed.
• Thermal comfort parameters: recommended ranges and measurement guidance for mean interior temperature, horizontal and vertical temperature gradients, surface temperatures, air velocity and relative humidity.
• Air quality & ventilation: fresh air volume flow rates, particulate filtration and air transfer between interior zones.
• Measurement & testing:
  • Air movement tests (air velocity, air volume flow rates, zone transfers).
  • Climatic tests (design-condition tests, extreme-condition tests, regulation tests and door cycling).
  • Requirements for test facilities, instrumentation, sensor positioning and data recording.
• Annex material: examples of exterior design temperature/humidity, PMV calculation results per vehicle category and a method to calculate recommended air velocity ranges.

Applications

ISO 19659-2:2020 is practical for professionals involved in railway HVAC and vehicle comfort engineering, including:

• Rolling stock designers and OEMs specifying HVAC system performance and passenger environment targets.
• HVAC suppliers and system integrators developing units for trains and trams.
• Testing laboratories and certification bodies conducting air movement and climatic tests to verify compliance.
• Operators and fleet managers setting comfort requirements in procurement and acceptance testing.
• Regulators and standards developers referencing measurement methods and performance criteria for passenger comfort.

Use of the standard helps ensure consistent, measurable passenger comfort outcomes, optimized HVAC sizing and energy management, and repeatable test procedures for compliance and acceptance.