Document Lda2Z56wbrLJY0dDVqeKZjXb

130 CHAPTER 6 1951 Guided' nearly horizontal/'It therefore appears,that the slope of the ET lines" may vary, depending upon the rate of work being performed. Fig. 10 shows the A.S:H.V.E. Comfort Chart** modified in several respects from the chart previously shown. The shaded areas and arrows indicating the summer and winter comfort zones have been removed. The summer comfort zone was removed because it extended to temperatures where too large a percentage of the people would be uncomfortable. The winter comfort zone was removed for the same reason, and because of inadequate data in later studies. i;Principles 131!- The distribution curve, showing the percent of people feeling comfortable at various effective temperatures, in summer, indicates that a maximum of 98 percent of the people were comfortable at 71 ET. The study was conducted with relative humidities between 30 and 70 percent. The distribution curve shown on the previously used chart, showing the percent of people feeling comfortable at various effective temperatures in the,winter, was based on research prior to 1932. This curve indicated that at 66 ET a maximum number of people were comfortable.' Later studies2* by the A.S.H.V.E. Research Laboratory indicated that a maxi mum of 97.7 percent of the people were comfortable at 68 ET, and this finding has been confirmed by current practice.*4 However, adequate 'data from the later studies were available only for the ET range of 65 to 69, Id. 9. EFFBcrtvii TEurEBATU^to^T Sho'WN Nomalj&a^ States Clothing: Custoznary indoor clothing. B. Activity: Sedentary or light muscular work. C. Heating A. l-i; Convection type, i.c., warm air, direct steam or hot water radiators, plenum systems. (cthod*. presented in Fig. 10. The studies should be extended to cover a wider ige. The lighter weight clothing,"probably'worn ;in .the later studies; j"oujn:t-sif:o--r the higrvh>ei>rudneasnitrsabtolerEooTm. surfaces, and between the occupants, ------'***'- oArriA