Overview
ISO/TS 14505-1:2007 - "Ergonomics of the thermal environment - Evaluation of thermal environments in vehicles - Part 1: Principles and methods for assessment of thermal stress" - provides guidelines for assessing thermal stress inside vehicle cabins (land, sea and air). It explains the principles for evaluating hot, cold and moderate thermal environments in vehicles, identifies measurement methods and the constraints specific to vehicle climate assessment, and points to applicable international methods and indices.
Key topics
- Assessment principles: Focus on three outcomes - heat stress (hot), thermal discomfort (moderate), and cold stress (cold) - and on evaluating stress to exposed occupants rather than HVAC performance alone.
- Measurement methods:
- Whole-body comfort using PMV/PPD (ISO 7730).
- Detailed local and whole-body assessment using equivalent temperature (ISO 14505-2) with heated sensors or full-scale thermal manikins.
- Heat stress indices such as WBGT and physiological models (ISO 7243, ISO 7933).
- Cold stress evaluation using heat-balance methods (ISO 11079) and contact-cold assessment (ISO 13732-3).
- Local effects and thermal asymmetry: Guidance for identifying asymmetric heating/cooling (e.g., solar radiation through glazing, directed airflows) and weighting measurements by affected body surface area.
- Environmental factors: Consideration of solar radiation, air velocity, evaporative heat exchange, metabolic rate and clothing insulation (Annex A provides measurement/estimation guidance).
- Subjective assessment: Use of human-subject studies to capture group mean sensation and variability (ISO 14505-3).
Practical applications
- Designing and validating vehicle HVAC systems and cabin layouts to reduce occupant thermal stress and complaints.
- Assessing occupational exposure for drivers and crew in extreme environments (hot/cold climates).
- Evaluating effects of glazing, seat design, ventilation outlets and local heating/cooling on passenger comfort.
- Informing risk analysis for heat- or cold-related health effects in transport operations.
- Creating test protocols in labs and field trials using thermal manikins, sensor arrays and human-subject studies.
Who uses this standard
- Automotive, maritime and aerospace designers and HVAC engineers
- Ergonomists and human factors specialists
- Occupational health and safety professionals
- Test laboratories and certification bodies
- Researchers studying thermal comfort and heat/cold stress in vehicles
Related standards
ISO 7730, ISO 14505-2, ISO 14505-3, ISO 7243, ISO 7933, ISO 11079, ISO 13731, ISO 13732-3, ISO 8996, ISO 9920
ISO/TS 14505-1:2007 is a practical reference for anyone assessing in-vehicle thermal environments and integrating objective measurements with human-centered evaluation methods.