Why Insulate Your House?
Heating and cooling account for 50 to 70% of the energy used in the average American home. Inadequate insulation and air leakage are leading causes of energy waste in most homes. Insulation:
- saves money and our nation's limited energy resources
- makes your house more comfortable by helping to maintain a uniform temperature throughout the house, and
- makes walls, ceilings, and floors warmer in the winter and cooler in the summer.
The amount of energy you conserve will depend on several factors: your local climate; the size, shape, and construction of your house; the living habits of your family; the type and efficiency of the heating and cooling systems; and the fuel you use. Once the energy savings have paid for the installation cost, energy conserved is money saved - and saving energy will be even more important as utility rates go up.
This section will help you to understand how insulation works, what different types of insulation are available, and how much insulation makes sense for your climate.
How Insulation Works
Heat flows naturally from a warmer to a cooler space. In winter, the heat moves directly from all heated living spaces to the outdoors and to adjacent unheated attics, garages, and basements - wherever there is a difference in temperature. During the summer, heat moves from outdoors to the house interior. To maintain comfort, the heat lost in winter must be replaced by your heating system and the heat gained in summer must be removed by your air conditioner. Insulating ceilings, walls, and floors decreases the heating or cooling needed by providing an effective resistance to the flow of heat.
Batts, blankets, loose fill, and low-density foams all work by limiting air movement. (These products may be more familiarly called fiberglass, cellulose, polyicynene, and expanded polystyrene.) The still air is an effective insulator because it eliminates convection and has low conduction. Some foams, such as polyisocyanurate, polyurethane, and extruded polystyrene, are filled with special gases that provide additional resistance to heat flow.
Reflective insulation works by reducing the amount of energy that travels in the form of radiation. Some forms of reflective insulation also divide a space up into small regions to reduce air movement, or convection, but not to the same extent as batts, blankets, loose-fill, and foam.
Note that the ability of insulation to limit air movement should not be confused with air sealing. Insulation reduces air movement only within the space it occupies. It will not reduce air movement through cracks and similar opening between or through building parts.
For example, adding insulation to a wwall cavity will not stop air that leaks between the foundation and sill place or between the wall joists and a window frame.
Which Kind of Insulation Is Best?
One of the most asked questions before homeowners buy insulation is "Which kind is the best?" The answer is that the 'best' type of insulation depends on several factors, including how much insulation is needed, the accessibility of the insulation location, the space available for the insulation, local availability and price of insulation, and other considerations unique to each purchaser.
Click Here to learn about the types of insulation and how to choose.
Insulating a New House
If you are buying or building a new house, make sure that energy-saving features are included. The Federal Trade Commission (FTC) home insulation rule requires the seller of a new home to provide information on the type, thickness, and R-value of the insulation that will be installed in each part of the house in every sales contract. Many state or local building codes include minimum requirements for home insulation. Be sure that your new home or home addition meets these building codes. You may wish to install insulation beyond the minimum specified in such codes, especially if those minimum levels are below those recommended here. Also, Energy-Efficient Mortgages may be available through both government-insured and conventional loan programs. These mortgages recognize that the homeowner's energy payments will be less for a more energy-efficient home, and therefore enable a buyer to borrow a larger sum to cover the up-front costs of improving the house's energy efficiency.
Click Here to read more about Insulating a New House
Adding Insulation to an Existing House
Does your home need more insulation? Unless your home was constructed with special attention to energy efficiency, adding insulation will probably reduce your utility bills. Much of the existing housing stock in the United States was not insulated to the levels used today. Older homes are likely to use more energy than newer homes, leading to higher heating and air-conditioning bills.
Click Here to read more about Adding Insulation to an Existing House