Personal environmental control: Effects of pre-set conditions for heating and lighting on personal settings, task performance and comfort experience

• We studied effects of preset temperature and lighting values on preferred settings.
• Preferred settings are dependent on preset values of heating power and illuminance.
• Offering higher preset values result in higher preferred values.
• Visual comfort increased with personal control but did not depend on preset values.
• We found no effects of personal control on thermal comfort.

The effects of pre-set environmental conditions of temperature and lighting on the preferred personal settings, comfort experience and task performance of office workers were investigated in an individually controlled workstation. Twenty subjects performed standardized tasks at a prototype workstation with individually controlled radiant heating and lighting in a climate room. In a repeated measures design, their adjustments to pre-set values were evaluated: low and high radiant heating power, low and high direct illuminance, low and high indirect illuminance. Results showed that preferred personal settings are dependent on the initial, pre-set values of radiant heating power and illuminance. Higher pre-set values result in higher adjusted operative temperatures and higher illuminances on desk, although the differences for heating were too small to show a convincing effect. After adjustment, visual comfort was higher, but it was not dependent of the pre-set values. For thermal comfort no differences were found. Individual task performance was not negatively affected. Providing personal environmental control and the way these concepts and interfaces are designed, play a significant role in user behavior and preferences. The design and control of individually controlled workstations as well as the interaction with the general level of the office environment should be carefully considered in order to obtain maximum comfort and energy efficiency.