Did you know that there is no rule requirement in regards to home team dugouts? Jonathan Light in The Cultural Encyclopedia of Baseball (1997) wrote, "It (the location) is sometimes based on the whim of the owner, in part depending upon where the owner's executive suite is and whether the dugout can be seen from that vantage point." Some are on the first base side and others are on the third base side and in the National League eleven of the sixteen teams have them on the first base side.
The sun itself actually plays a role in rule 1.04 as modern ballparks are "supposed" to be designed & built so that the sun sets behind third base and shines on right field — where fly balls are less frequent due to the larger number of right handed hitters.
The sun, the owner, the dugout, the wind, the physical position of the site where the ballpark is built, and other factors are all taken into account in ballpark construction. Share what you know about your favorite ballpark on Baseball Fever.