Field Study Of Thermal Comfort Research Articles

関西地域の住宅における熱的快適性に関する実態調査 : 夏期の中立温度と許容範囲

This report presents the findings of a field study of thermal comfort and thermal environment in 30 detached houses in Hyogo, 30 apartment houses in Osaka,Japan. A total of 70 subjects provided 459 sets of data for summer,each accompanied by indoor climatic measurements. The sample of subjects consisted mostly of housewife. The average clothing insulation levels were 0.28clo. The average metabolic rate was 1.3met.Thermal neutrality, according to responses on the ASHRAE seven-point sensation scale, occurred at 27.6℃. The Operative temperature corresponding to the accepted thermal environment by 80% of the occupants is under 28.4℃.

03/01966 Thermal comfort and psychological adaptation as a guide for designing urban spaces: Nikolopoulou, M. and Steemers, K. Energy and Buildings, 2003, 35, (1), 95–101

Air conditioning technologies (HVAC) have dramatically shaped today's building environment. However, the mutually dependent relationship between the indoor climate experience and occupants' thermal comfort adaptation rarely been given attention. To investigate the dynamic processes of adapting to different indoor climates, two comparative thermal comfort field studies were conducted in China, where the northern cities such as Beijing (with district heating) have much warmer indoor temperatures than the southern cities such as Shanghai (without district heating) during the winter. The results indicate that occupants' thermal comfort adaptation exhibits asymmetric trajectories. Building occupants can raise their expectations much faster to accept a neutral indoor climate than they can lower their expectations and acclimate to underconditioned environments. The northern groups took 3 years to adapt to cold indoor temperatures while the southern groups accepted neutral and warm indoor temperatures in less than 1 year. These dynamic processes are well reflected by the ‘demand factor’ metrics. Furthermore, we discussed the practical implications of the asymmetric nature of building occupants' thermal adaptation. It can not only help elucidate the underlying principles behind adaptive comfort phenomena but also help guide building design and operation.

A field study of thermal comfort in outdoor and semi-outdoor environments in subtropical Sydney Australia

In the absence of empirical outdoor thermal comfort studies it has been widely assumed that indoor thermal comfort theory generalises to outdoor settings without modification. Many indoor models were developed to describe thermal discomfort, not stress, therefore their relevance to conditions that vary greatly from neutrality, as many outdoor climatic conditions do, has not been critically validated in the field to date. The thermal comfort of 1018 subjects in outdoor and semi-outdoor locations in subtropical Sydney was investigated by a questionnaire and a comprehensive package of micro-meteorological instruments. The thermal neutrality in terms of the thermal comfort index OUT_ SET ∗ of 26.2°C was significantly higher than the indoor SET ∗ counterpart of 24°C (ASHRAE Trans. 92 (1986) 709).

Environmental and human factors influencing thermal comfort of office occupants in hot—humid and hot—arid climates

The effects of environmental and individual factors on thermal sensation in air-conditioned office environments were analysed for two large, fully compatible thermal comfort field studies in contrasting Australian climates. In the hot—humid location of Townsville, 836 office workers were surveyed; 935 workers participated in hot—arid Kalgoorlie-Boulder. Overall perceived work area temperature and measured indoor operative temperature correlated moderately with thermal sensation for Townsville (T) subjects but only perceived temperature correlated with Kalgoorlie-Boulder (KB) sensation. Multiple regression analyses confirmed that indoor climatic variables (including Predicted Mean Vote) contributed to actual thermal sensation vote (24% T; 15% KB), with operative temperature having more of an effect in T than in KB. Subsequent analyses of individual characteristics showed no linear contributions to thermal sensation. The remaining variances were significantly related to perceived work area temperature (7% additional explained variance in T; 12% in KB). Mann Whitney analyses (after correction for climatic variables) showed that T subjects with higher job satisfaction had thermal sensations closer to ‘neutral’. Males, healthier subjects, non-smokers, respondents with earlier survey times and underweight occupants had lower median thermal sensations in KB. Townsville occupants appeared more adapted to their outdoor climatic conditions than Kalgoorlie-Boulder respondents, perhaps due to limited home air-conditioning. Further research into non-thermal impacts on gender-related thermal acceptability is suggested.

A comparative analysis of short-term and long-term thermal comfort surveys in Iran

This paper describes two field studies of thermal comfort conducted in Ilam, a city located in western Iran. The first study consisted of two short-term surveys carried out during two climatically extreme periods—a hot summer and a cold winter—in 1998. The second study consisted of a long-term survey that collected data throughout the whole of 1999. Both studies were performed in naturally ventilated buildings. This paper shows some comparative analysis between the findings from the short-and long-term studies. For the hot season the neutral temperatures from the short-and long-term studies were 28.4 and 26.7 °C, respectively. For the cold season the short-and long-term neutral temperatures were 20.8 and 21.2 °C, respectively. The results show a very good agreement between both studies in Iran. The main points of interest from the studies were the variability of acceptable conditions, a good relationship between neutral temperature and room temperatures and also, more importantly, between indoor comfort and outdoor conditions. The findings reveal that the people in the study could achieve comfort at higher indoor air temperatures compared with the recommendations of international standards such as ISO 7730.

Activity rates and thermal comfort of office occupants in Sydney

Designs for air conditioning systems are based on steady-state equilibrium theories of heat exchange and rely on the estimation of an average activity rate for building occupants. This is, however, an uncertain procedure. In a longitudinal field study of thermal comfort in an office building in Sydney, weightings were applied to self-reported activity rates to account for decay over the hour preceding the report. The average rate was nearly constant at 1.2 met, in good agreement with other recent studies. However random individual variability may be a cause of some of the frequent complaints about thermal comfort in offices.

A tale of two populations: thermal comfort in air-conditioned and naturally ventilated offices in Thailand

A field study of thermal comfort was conducted in Bangkok, Thailand, in which over 1100 office workers responded to a questionnaire while simultaneous physical measurements were taken. In this study we explore whether there is justification for adopting a comfort standard that differs from those developed for office workers accustomed to more temperate climates. Both air-conditioned and naturally ventilated offices were surveyed. Participants cast votes on standard subjective thermal rating scales and these were correlated with temperature indices that variously account for the thermal impacts of humidity, radiant temperature, air velocity, and clothing levels. Following the criteria used in developing a widely adopted thermal comfort standard, it was found that the upper temperature bound for a Thai comfort standard, instead of being the currently accepted level of 26.1 °C for those accustomed to air-conditioning accustomed to naturally ventilated spaces, and as high as 28 °C for those accustomed to air-conditioning. Comparing the responses from the naturally ventilated buildings with both those from the air-conditioned buildings and from studies conducted in the temperate regions provides convincing evidence of acclimatization. These and other findings of this study suggest that interior spaces in Thailand can be cooled to a far lesser degree without sacrificing comfort.

Field studies of thermal comfort compared and applied : Humphreys, M.A.Building Services Engineer, Apr 1976, 44.1, 5–23

Field studies of thermal comfort compared and applied : Humphreys, M.A.Building Services Engineer, Apr 1976, 44.1, 5–23