Maximum solar heat gain factors for externally shaded glass

Values based on a ground reflectance of 20%

From ASHRAE (1989), with permission

Notes:

Month Btu/hr·ft2 for given orientation

N

NE/NW

E/W

SE/SW

S

HOR

Jan

31 31 34 37 38 16

Feb

34 34 36 38 39 46

Mar

36 37 39 40 39 17

Apr

40 41 42 41 40 24

May

43 45 45 41 40 28

Jun

45 47 46 41 40 31

Jul

45 46 47 42 41 31

Aug

42 43 46 43 42 28

Sep

37 38 41 42 41 23

Oct

34 34 38 40 40 19

Nov

32 32 34 38 39 17

Dec

30 30 32 36 37 15