Equivalent contact temperature (ECT) for personal comfort assessment – analytical description and definition of comfort limits

Ergonomics, vol. 67, pp. 207–224

Abstract

This paper introduces the equivalent contact temperature (ECT) model for local thermal comfort assessment in contact areas for non-uniform environmental conditions. It aims to complete the comfort evaluation scheme of the equivalent temperature approach included in ISO 14505-2 by the contact areas back and buttocks that are currently neglected in the standard. For the assessment of local and overall thermal comfort of seated persons, these contact areas are of great importance, especially if exposed to personal comfort systems. Person-oriented climatization systems, such as seat heating and ventilation, are much more energy efficient than conventional HVAC systems and allow to incorporate the human individual into the system's control loop. The ECT-approach is formally defined, analytically as well as mathematically derived and validated by a subject study. The results of the subject study (air temperature of 26 °C and 29 °C) confirm the cooling effect due to the seat ventilation and show fundamental correlations between ECTs and body part specific mean thermal votes for buttocks and back.

Authors 5

1. Alexander Warthmann corresponding Aachen Institute of Energy Efficiency and Sustainable Building E3D

   RWTH Aachen University

   Affiliation as printed

   Institute of Energy Efficiency and Sustainable Building E3D, RWTH Aachen University, Aachen, Germany

   Institute of Energy Efficiency and Sustainable Building E3D, RWTH Aachen University, Mathieustr. 30, 52074 Aachen, Germany

2. Itsuhei Kohri

   Tokyo City University

   Affiliation as printed

   Department of Mechanical Systems Engineering, Tokyo City University, Tokyo, Japan

   Department of Mechanical Systems Engineering, Tokyo City University, 1-28-1 Tamazutsumi, Setagaya-ku, 158-8557 Tokyo, Japan

3. Yoshiichi Ozeki
   Affiliation as printed

   AGC Inc., Innovative Technology Laboratories, Yokohama-city, Japan

4. Hideaki Nagano

   Tokyo City University

   Affiliation as printed

   Department of Mechanical Systems Engineering, Tokyo City University, Tokyo, Japan

   Department of Mechanical Systems Engineering, Tokyo City University, 1-28-1 Tamazutsumi, Setagaya-ku, 158-8557 Tokyo, Japan

5. Christoph van Treeck Aachen Institute of Energy Efficiency and Sustainable Building E3D

   RWTH Aachen University

   Affiliation as printed

   Institute of Energy Efficiency and Sustainable Building E3D, RWTH Aachen University, Aachen, Germany

   Institute of Energy Efficiency and Sustainable Building E3D, RWTH Aachen University, Mathieustr. 30, 52074 Aachen, Germany