Kulve, M. te3; Boerstra, A. C.4; Toftum, Jørn1; Loomans, M. G. L. C.3
1 Department of Civil Engineering, Technical University of Denmark2 Section for Indoor Environment, Department of Civil Engineering, Technical University of Denmark3 Eindhoven University of Technology4 BBA Binnenmilieu
Field studies have demonstrated that personal control over the indoor climate may increase comfort and could reduce SBS symptoms. A laboratory study was performed to investigate if being in control over the thermal environment influences comfort, symptoms and performance. The central hypothesis was that human responses to a thermal indoor environment depend on the availability of control opportunities. This was tested in a field lab where subjects had a personal desk fan with a stepless controller at their workplace. Two conditions were tested: one (the first) with individual control and one without, but with identical indoor climate exposure as recorded during the first session. During both experimental conditions, 23 subjects were exposed for 120 min to an operative temperature of 28 °C and they were provided with a personal desk fan. During the first exposure subjects were allowed to adjust air velocity (and therefore local thermal environment) at any moment. For each subject the adjustments were recorded. In the second experiment, subjects were exposed to identical indoor environment conditions as recorded during the first experiment, but without individual control of the desk fan (control knob was hidden). During both conditions identical questionnaires and performance tests were used to evaluate comfort, symptom intensity and performance. Limited differences were found when comparing the ‘with control’ and ‘without control situation’. For the investigated case, the availability of control opportunities does not directly influence human perception to the thermal environment, symptoms or performance. However, personal preferences for the air velocity of the fan differ a lot. This confirms the need for personal indoor climate systems to satisfy the need of individuals.