Orientation of the home also matters in this instance. For example, the front of my home faces the east. There is a room upstairs which has a very large window and a cathedral ceiling. There are already three strikes against keeping this room cool in the summer. First of all, the sun shines directly into the room in the morning because the sun rises in the east. Second, heat rises (second floor). Third, there is the cathedral ceiling which means there is no attic. The heat has nowhere to go but to stay in the room.
There are many other ways that homes retain heat. For example, using the oven creates heat. Heat also enters through windows. One way to prevent this from happening is by covering windows with solar shades.
The sun's rays beating through a window and on a rooftop can drastically raise the internal temperature of a home. This process is called external heat gain. There are several things you can do to prevent this. You can plant a tree to block the sun, change the color of your roof tile, and hang up window coverings.
A second type of home heating is called internal heat gain. Internal heat gain comes from the collection of heat given off by sources inside the home. Some examples of these are electronics, appliances, and lighting.
Heat may enter in a house during summer in following ways.
- Conduction of heat from the surroundings at higher temperature through the roof, walls, and closed doors and windows of the house.
- Absorption of the radiation radiation falling on opaque outer surface of the house. This may heat up the outer surface to temperature that is higher than the ambient air temperature. This heat is again conducted through walls,roofs, door and windows.
- Heat radiations coming directly inside the house through open windows and doors, and other openings. The radiation heat also enters a house through transparent structures such as glazed widows.
- Hot atmospheric air entering the house through openings such as doors and widows. Such air flow may be caused by local convection effect or by general wind or breeze.
- In very cold place, where temperature may be near 0 degrees centigrade even in summers, geo-thermal energy enters the house through floors also. In such places geothermal energy can be used to keep house warm by building underground vaults.