ASHRAE-Standard-55 - Page 033

Extracted Content

 fbes = 1 fbes = 0.5 fbes = 0.3

Figure C-2 Fraction of body exposed to sun fbes , not including the body’s self shading. It is acceptable to simplify fbes to equal the fraction of the distance between head and toe exposed to direct sun, as shown. ( Informative Note: 1.0 is the greatest possible value for fbes, because the body’s self shading is not included in fbes .)

Range of Inputs

Min to Max

horizontal

t Variables and Ranges for Calculation Procedure	Col2	Col3
Description	Unit	Allowable Default Value
Short-wave radiation absorptivity	—	0.7
Fraction of sky vault exposed to body	—	N/A
Window system glazing unit plus shade solar transmittance	—	N/A
Direct solar beam intensity	W/m2	900
Fraction of the possible body surface exposed to sun	—	N/A
Solar altitude angle	deg	N/A
Solar horizontal angle relative to person	deg	N/A
Posture (seated, standing, or horizontal)		N/A

ANSI/ASHRAE Standard 55-2023 31