Indoor environmental problems increasingly are being identified with air quality. Louis Harris reported that 51% of the office workers surveyed indicated the need for improved thermal comfort at work.
Energy conservation measures, poorly trained or informed building operators, badly designed, installed or maintained equipment, or other problems result in poor thermal control of the indoor environment. Once thermal comfort is achieved, complaints from employees often diminish significantly.
Thermal comfort preferences vary significantly from one person to another. Estimates of the minimum number of individuals likely to prefer warmer or cooler conditions range from about 5-12% depending on the source. Individual thermal comfort is a subjective evaluation based on thermal sensations.
Researchers at the University of California, Berkeley, found that at “optimum” thermal comfort conditions (about 72.5 F or 22.5 C), 12% of employees surveyed were nonetheless uncomfortable with their thermal environment. (Source: here)
Optimal temperature is the theoretical point where the least number of people are likely to experience a thermal discomfort (Source: here)
Human body’s heat balance system is developed to cope with the outdoor climate. Clothing is generally matched to the activity and climate outdoors. But indoors, “quite small deviations from the individual optimum temperature can have powerful negative effects on efficiency.” (Source: here)
Moderate cold can reduce manual speed, sensitivity, and dexterity by up to 20%. Whereas moderate heat can reduce reading speed, typewriting, and the kind of logical thinking required for mathematics by up to 30%. According to David Wyon, people do about 30% less work at 24 C than at 20 C. His solution is to provide employees with individual control over their thermal environment. (Source: here)
Berglund and Cain at Yale University contradicts Wyon’s observation and suggest that employees find air quality considerably less acceptable as temperature climbs through and above the traditional indoor comfort range of 20-26 C simply because 25-26 C will not be acceptable when indoor air quality and the total indoor environment are considered as they affect employees’ comfort, health, and satisfaction.
Temperatures in excess of 24 C will nearly always increase dissatisfaction with indoor air quality and are likely to increase symptoms of sick building syndrome due to thermal discomfort and secondary effects of elevated temperature. (Source: here)
The researchers suggested that a considerable loss in productivity or increased absenteeism may result from discomfort or adverse health effects.
In offices where employees individually control the temperature, there was a 34% reduction in sickness due to sick building syndrome. (Source: here) If employees could control temperature, humidity, or lighting, self-intimates of productivity increase dramatically.
A substantial amount of research shows that the thermal environment profoundly influences people’s reactions – whether they be health, comfort, satisfaction, or productivity responses. It may include perceptions of indoor air quality, satisfaction with the indoor environment, performance on tasks, and effects of volatile organic compounds.
What do you think about your office’s thermal environment – too hot, too cold, or just right?