The sun travels east to south to west in the northern hemisphere (east to north to west in the southern hemisphere). In the northern hemisphere, for most of the day, the sun is shining from the south. The sun heats the ground and south facing walls, so that side of the house can become hot. The trade-off is that these south facing walls get the best light. The north facing walls conversely, are dark and have very little light, however they are cooler. If the temperature is too hot in your south facing walls you could consider planting some trees for shade or changing your windows to a higher quality insulating window or adding shapes. Air conditioners can usually maintain a 25 degree temperature difference between the inside and outside temperatures. The coolest an air conditioner can get is somewhere around 52 degrees. Air conditioner’s should not be run when outside temperatures are below 65 degrees, or they may break.
East facing windows get soft morning light- but be careful, if your bedroom is facing this direction you will be waking up early when the sun rises. Some owners use thick shades to block the morning light when they want to sleep in. I personally think that it’s an advantage to have a bedroom facing east for that very reason; however I always feel like I am running late if I haven’t woken before the sun has come up.
West facing walls and windows get afternoon and evening light. So, the east side of the home in the evening will be cooler than the west side, however from the east side of the house, you will not be able to observe the sunset. Since the sun sets in the West, the west side of the home is warmer than the east side.
There is a real estate axiom that home buyers like “Light and Bright” as oppose to “Dark and Scary” I suppose. Natural light plays a big part in your mood. Sunlight helps the body produce Vitamin D which is an important compound in fighting seasonal depression. Also regular sunlight, keeps your bodies circadian system in balance, so that you can avoid those feelings like you feel when you are jet lagged. Light is also important because human beings are actuarial creatures (as opposed to nocturnal) and we are our happiest when we are awake during the day and asleep during the night.