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Air Quality Part 14

Tham khảo tài liệu 'air quality part 14', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 318 Air Quality When Brager studied office buildings in San Francisco during the winter he revealed that the PMV was found to be lower colder than the obtained thermal sensation. That defined a neutral temperature of 24.8 C which was 2.4 C above the estimated value. After considering various UK offices with mechanical ventilation it was demonstrated that the PMV differed by 0.5 points with the thermal sensation which is equivalent to 1.5 C differences. In Australia Dear and Auliciems 1985 found a difference of 0.5-3.2 C between the neutral temperatures estimated by surveys and determined by the PMV model of Fanger. Subsequently Dear conducted a study in 12 Australian office buildings it was defined that a temperature difference between neutral temperatures proposed by surveys and PMV was determined to about 1 C. Dear et al. extended their studies to those made by Brager. They returned to analyze and correct the data by the seat isolation. Again discrepancies were found between the neutral temperature based on the value obtained through surveys and the value predicted by the equations. As a result it seems that for real conditions the thermal sensation of neutrality is in line with a deviation of the order of 0.2-3.3 C and an average of 1.4 C of the thermal neutrality conditions. The error was attributed to a PMV erroneous definition of the metabolic activity and the index of clo or unable to take into account the isolation of the seat. The Institute for Environmental Research of the State University of Kansas under ASHRAE contract has conducted extensive research on the subject of thermal comfort in sedentary regime. The purpose of this investigation was to obtain a model to express the PMV in terms of parameters easily sampled in an environment. As a result an investigation of 1 600 school-age students revealed statistics correlations between the level of comfort temperature humidity sex and exposure duration. Groups consisting of 5 men and 5 women were exposed to