Indoor temperature - office work performance database

The objective of developing this database was to summarise all relevant published studies that have linked the thermal environment to office work performance within the most representative temperature range for office buildings (20 °C to 30 °C). We conducted a comprehensive literature review and collected the relevant published data into our database. A variety of combinations of keywords including temperature, thermal sensation, work, cognitive, and task performance, and office and commercial buildings, were used.

In total, we found thirty-five studies, in 29 peer-reviewed journal publications and 571 measures of performance, met our inclusion criteria. We normalised these measures using a method originally proposed by Seppänen et al. (2006; 2006). This method uses the change in work performance per 1 °C increment in temperature (λ%), which is measured in percentage per degree Celsius (%/°C). Our database comprised a total of 358 data points for λ%.

Furthermore, we developed a web-based interactive tool with an easy-to-use interface to visualize the relationship between temperature and office work performance. This tool can automatically calculate the model’s equation and accuracy metrics via different data subsets and regression models.

Methods
Our literature search strategies and data collection criteria are specified below:

We searched electronic databases of scientific publications from September 2019- March 2020, including Google Scholar, Web of Science, Elsevier, PubMed, and ProQuest.      

A variety of combinations of keywords were used.
We looked only for peer-reviewed journal articles that reported both thermal environment measurement data and the subject’s performance of office work. Diverse measures were considered to describe office work performance including diagnostic tests, simulated office work tasks, and existing outcome metrics.
We used air temperature as a proxy of the thermal environment in our research scope because it was extensively measured in most of the studies.
We did not include the following conditions in our database:

Physiological measurements providing information on cognitive load EEG, ECG, heart rate variability, and pupillary responses;
Studies that reporting only self-estimated performance;
Proxies for reduced performance, such as the prevalence and intensity of acute health symptoms, especially for fatigue, difficulty in concentrating, sleepiness, or headaches;
Data from factory workers, university students, or primary/secondary school children;
Any experimental conditions that have a low-temperature condition (TL) below 17 °C or the high-temperature condition (TH) above 36 °C;
Studies where thermal stress was induced by any means other than the indoor thermal conditions (e.g., exercise or water immersion).

From each study, we retrieved the year of publication, journal, and information regarding the study location, whether the study was or was not performed in a controlled environment, the sample size, age group, occupation of the participants, clothing, and physical activity level. We also collected the tasks or tests used to measure performance, the performance metrics and outcomes, and the temperature conditions to which the participants were exposed.

We normalised the performance data obtained from the studies using the method proposed by Seppänen et al.(2006). This approach assumes that performance changes linearly within the high temperature (TH) and low temperature (TL) range examined in each study regardless of the performance measure used and the temperature range. We calculated the change in work performance in % per 1 °C increment in temperature (λ%), whereby positive λ% indicates an increase in performance with increasing temperature; while negative λ% indicates a decrease in performance with increasing temperature. The detailed normalisation process can be seen in Porras-Salazar et al. (2021).

References:

Seppänen, O., & Fisk, W. J. (2006). Some quantitative relations between indoor environmental quality and work performance or health. HVAC and R Research, 12(4), 957–973. https://doi.org/10.1080/10789669.2006.10391446

Seppänen, O., Fisk, W. J., & Lei, Q. H. (2006). Effect of Temperature on Task Performance in Office Environment. Proceedings of 5th International Conference on Cold ClimateHeating, Ventilating and Air Conditioning. Moscow, Russia.

Porras-Salazar, J.A.; Schiavon, S.; Wargocki, P.; Cheung, T. & Tham, K.W. (2021) Meta-Analysis of 35 Studies Examining the Effect of Indoor Temperature on Office Work Performance. Building and Environment, 203. https://doi.org/10.1016/j.buildenv.2021.108037