Abstract
Background: The effects of the correlated color temperature (CCT) of light on thermal sensation and comfort have been tested repeatedly over the last few decades. Based
on the hue-heat hypothesis, it is often assumed that yellowish light (low CCT) induces a warmer temperature sensation than bluish light (high CCT) does, and therefore, a
low CCT is expected to improve thermal comfort in thermally cold conditions compared to high CCT. However, results are rather inconsistent and most previous studies only
focused on short-term effects (<1 hour).
Method: The current study investigated, with a relatively long exposure (>2 hours), the effects of CCT on thermal comfort in mild cold conditions (17˚C). Sixteen participants
(8 males and 8 females) completed two CCT scenarios during daytime in an office-like setting: 2700 K vs. 5700 K and 500 lux at the eye. Thermal perceptions and
thermophysiological parameters were measured repeatedly.
Results: In contrast to the hue-heat hypothesis, thermal sensation was, on average, unaffected by CCT in mild cold conditions. Interestingly though, thermal comfort was
increased by high CCT (5700 K) while perceived shivering (an indication of muscle tension) was decreased. Most physiological parameters (mean skin temperature, skin
blood flow, heart rate measures, physical activity and substrate oxidations) were not significantly affected by CCT, but energy expenditure increased after a one-hour
exposure to 5700 K and the average diastolic blood pressure was lower in 5700 K 342 throughout the 2 hours. A correlational analysis indicated that thermal comfort was
negatively associated with perceived shivering.
Discussion: Together, the results did not support the hue-heat hypothesis. In contrast, with a relatively long exposure duration, the higher CCT improved thermal comfort in
mild cold conditions, possibly via decreasing perceived shivering and/or eliciting some changes related to decreased perceived shivering.
on the hue-heat hypothesis, it is often assumed that yellowish light (low CCT) induces a warmer temperature sensation than bluish light (high CCT) does, and therefore, a
low CCT is expected to improve thermal comfort in thermally cold conditions compared to high CCT. However, results are rather inconsistent and most previous studies only
focused on short-term effects (<1 hour).
Method: The current study investigated, with a relatively long exposure (>2 hours), the effects of CCT on thermal comfort in mild cold conditions (17˚C). Sixteen participants
(8 males and 8 females) completed two CCT scenarios during daytime in an office-like setting: 2700 K vs. 5700 K and 500 lux at the eye. Thermal perceptions and
thermophysiological parameters were measured repeatedly.
Results: In contrast to the hue-heat hypothesis, thermal sensation was, on average, unaffected by CCT in mild cold conditions. Interestingly though, thermal comfort was
increased by high CCT (5700 K) while perceived shivering (an indication of muscle tension) was decreased. Most physiological parameters (mean skin temperature, skin
blood flow, heart rate measures, physical activity and substrate oxidations) were not significantly affected by CCT, but energy expenditure increased after a one-hour
exposure to 5700 K and the average diastolic blood pressure was lower in 5700 K 342 throughout the 2 hours. A correlational analysis indicated that thermal comfort was
negatively associated with perceived shivering.
Discussion: Together, the results did not support the hue-heat hypothesis. In contrast, with a relatively long exposure duration, the higher CCT improved thermal comfort in
mild cold conditions, possibly via decreasing perceived shivering and/or eliciting some changes related to decreased perceived shivering.
Original language | English |
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Title of host publication | Proceedings of Healthy Buildings 2023 Europe |
Editors | Marcel Schweiker, Christoph Van Treeck, Dirk Mueller, Janina Fels, T Kraus, Hannah Pallubinsky |
Publisher | ISIAQ International |
Publication status | Published - 1 Aug 2023 |
Event | Healthy Buildings Europe 2023: Beyond Disciplinary Boundaries - Aachen, Germany Duration: 11 Jun 2023 → 14 Jun 2023 |
Conference
Conference | Healthy Buildings Europe 2023 |
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Abbreviated title | HB2023EU |
Country/Territory | Germany |
City | Aachen |
Period | 11/06/23 → 14/06/23 |