Basic Concepts of Energy Efficiency
You can make a lot of progress toward improving the energy efficiency in your home by simply plugging the many places through which air can get in or get out. Plugging your home is called "air sealing," and it is one of the most important first steps to take when weatherizing your house to increase its energy efficiency.
Increasing the amount of insulation in various places in your home should be a high priority. Insulation, in its many forms, helps stop the transfer of heat from one place to another. A good example of this is the insulation in your attic. A thick layer of insulation helps stop heat flow from the house to the attic during the winter. In the summer, that same insulation helps stop heat transfer from the hot attic to the rooms below.
But while better air sealing and insulation in your home can do a lot to reduce your utility bill, that's not where the story on energy efficiency starts and ends. There are many other ways to conserve, some of which require only simple changes of habit or lifestyle.
Electricity powers lights, appliances, and electronic devices in your home. It also runs air conditioners, heats water, cooks food, dries laundry, and in some cases is used for space heating. Natural gas, propane, and oil are mostly burned to provide space heating and hot water; and secondary uses for these gases include cooking, clothes drying, and fireplace fuel.
Electricity: Electricity enters a home through a service-entry cable either above or below ground. From there it passes through a main electrical service panel...