Heat exchange through a surface like a roof, duct, attic, or wall is reduced by insulation. When a house is well-insulated, a lower amount of warm air will escape from the home in the winter, and during the summer less cool air will escape. This will reduce how much energy is needed for cooling and heating. When the insulation is improved in an older structure it can reduce your yearly cooling and heating bill by as much as 20 percent.
The envelope, or outer shell, of your house, is the barrier that prevents the outside and inside temperatures from equalizing. Well-insulated roofs, floors, and walls will result in your cooling and heating systems having to use less energy to cool or warm the air inside your house. Since heat rises, it is very important to insulate your roof to keep warm air indoors in cold climates. Next article.
Even well-insulated walls can allow cool or warm air to escape through the gaps and cracks around doors and windows. Drafty houses need more power than tight houses to cool and heat. To save energy, use weather-stripping and caulking to prevent air leaks. It is nearly impossible in older homes to seal a house too tightly due to the construction methods, ha are used. There will be enough fresh air still for good ventilation to be maintained after the biggest leaks are sealed.
In houses that have central air-conditioning and heating units where the air is forced through the duct system, efficiency can be reduced by as much as 20 percent if there are leaking ducts. All of your home's ducts should be sealed and insulated to allow the cool and warm air to get to where it is supposed to be as efficient as possible. It is even more important to have good insulation when the ducts move through unfinished areas such as basements or attics. Learn more here. Also, seal the areas surrounding the registers in order to prevent air from leaking under the floor or behind the walls.
Although heat transfer is reduced by most insulation by blocking it physically, reflective insulation, or a radiant barrier, can be installed on your attic floor. It will reflect the heat that is radiated by a hot roof into the attic and prevent it from getting into the living area below. Although refective insulation can help to lower heating bills, the main purpose it provides is keeping your home cool in a hot climate.