East window: Sunlight comes in at the earliest of the day. Curtains can be light in texture and light in color, which can let the sun shine into the room for the first time and bring in heat.
South window: The sun shines for a long time and is less affected by the northwest wind, so the room with the south window has sufficient heat and light. Curtains mainly consider shading, and the color can be darker.
West window and north window: The curtain color is mainly dark and warm, and the material can be made of thick materials such as cotton or flannel, which can better block the invasion of cold wind, and also has the effect of sound insulation and dust prevention.