Your Home’s Insulation May Be Out of Sight, But Is It Adequate?

Published on: November 15, 2013

You rarely have the opportunity to see the insulation in your home, but this material is vitally important to keeping your home cool in the summer and warm in the winter. Without proper levels of insulation, heat would rapidly leak out of your home in the winter and infiltrate your indoor spaces in the summer. Lack of proper insulation means your HVAC equipment will work harder than necessary and you will pay more to heat or cool your home. The following brief guide to insulation will help you understand the importance of insulation and how you can improve the insulation level in your home to boost comfort, energy efficiency and savings on energy bills.

What Is Insulation?

Insulation, in the HVAC context, is a material that resists the flow of heat. It stops heat from leaving the inside of your home in the winter and from coming into your home during the summer. The most common types of insulation are made of spun fiberglass or cellulose and are installed in the walls, floors and ceilings of homes, commercial buildings and other structures.

The effectiveness of insulation is indicated by its R-value, which is a numerical indicator of how well the material will stop heat flow. The higher the R-value, the more effective the insulation will be. The U.S. Department of Energy recommends R-values in the following ranges for areas in the Southeastern United States (Florida, Georgia, South Carolina, Mississippi and Alabama):

  • Attic: R30 to R60
  • Cathedral ceiling: R22 to R38
  • Wall cavity: R13 to R15
  • Floor: R13 to R25

Common Types of Insulation

Insulation is available in various types that are appropriate for specific applications.

  • Blanket, batt, or roll: Blanket insulation is made from layers of spun fiberglass and is probably the most common type of insulation found in home construction. It consists of the thick, pink-colored, paper-covered material that is purchased in large rolls. This type of insulation is put in walls between beams, studs and joists; in ceilings; in foundations; and in floors.
  • Loose fill: This type of insulation is usually made of small pellets of cellulose, fiberglass or other insulating material. The pellets are intended to create a thick layer when installed. They are blown into openings and cavities such as unfinished floors, walls and ceilings. This type of insulation is also used to add insulation in irregularly shaped areas or in spots that would be hard to reach with blanket insulation.
  • Spray foam and foam-in-place: Foam insulation is commonly used to fill cavities in walls, floors and other large open areas or places that are hard to reach with other types of insulation. The foam is made of polyurethane or plastic and is sprayed into the openings using a specialized pressure sprayer. It expands slightly and effectively fills up the area where it is installed. When dry, it produces an effective layer that has no gaps or openings that could reduce its insulating properties. Dry foam insulation has a consistency somewhat like brittle styrofoam.
  • Reflective insulation: This type of insulation is designed to reflect heat away from surfaces and areas where it is applied. It is usually made of heavy foil-coated paper, cardboard, or plastic film. It is most often used in the same places as blanket insulation, such as in walls, floors and ceilings.
  • Rigid foam board: This type of stiff polystyrene or polyurethane board is commonly used in floors, roofs, walls and ceilings. You may also find rigid foam board insulation on your HVAC system’s ductwork, where it prevents energy loss through the thin metal of the ducts. Keep in mind that rigid foam board insulation may require additional precautions to comply with fire safety codes.

Cellulose vs. Fiberglass Insulation

Cellulose and fiberglass insulation have different qualities that should be carefully considered when choosing which type of insulation to install. Cellulose is usually made of ground-up and processed newspaper that is formed into the pellets common to loose-fill insulation. Cellulose insulation can settle and lose thickness over time, which reduces its insulation ability and R-value. It also presents a potential safety hazard since it is made of flammable paper that can burn at about 450 degrees, about the surface temperature of a standard 75-watt light bulb. The fire-retardant chemicals applied in the manufacturing process can lose effectiveness over time. Cellulose is also very absorbent, which means it can easily soak up water that eliminates its effectiveness as insulation. Wet cellulose can also be an attractive food source for mold and insects.

Fiberglass insulation, in contrast, is made of nonorganic glass fibers that are not combustible and that resist water. Fiberglass insulation maintains its shape and thickness over time and does not settle, which means it does not lose R-value. Fiberglass will not absorb water and is not a potential food source for pests.

The Benefits of Insulation

When your home is properly insulated, you’ll see several significant benefits.

  • Improvements to indoor comfort levels: Since the insulation prevents heat transfer into or out of your home, your living spaces will maintain more consistent temperatures. Overall comfort levels will be increased throughout the structure and hot and cold spots will be eliminated. Even rooms that are the farthest away from your HVAC equipment will benefit from the addition of insulation.
  • Regular savings on your energy bills: If your house is well insulated, it will cost less to heat and cool it. Energy is not lost through the walls, floors and ceilings of your home, which means it stays where it belongs to provide heating or cooling. Your furnace, heat pump or air conditioner will be able to operate at a lower cost-saving level while still providing the same level of indoor comfort. HVAC equipment will not receive as much wear and tear, which reduces the chances of costly breakdowns or malfunctions.
  • Soundproofing: A good layer of insulation provides the surprising benefit of soundproofing your home. It will help reduce the amount of noise you hear from outside and from other areas inside your home.

Adding Insulation

It is relatively common for insulation levels, especially in older homes, to be inadequate. You can hire a qualified home energy auditor to inspect your home and evaluate your insulation levels. The audit process takes into account amount and location of existing insulation, areas of heat and energy loss, air leaks and other factors that could affect your home’s energy efficiency. When you have the results of the audit, you’ll be able to accurately determine where insulation should be installed or increased.

You can also check your own insulation using a few simple steps.

  • Locate areas where you can easily see into spaces behind walls, in ceilings or in floors. These may be in the attic, walls and floors next to an unheated area, such as a garage. Remove paneling or other structural elements if possible. Visually confirm what type of insulation is present in those spaces. Measure the insulation’s depth or thickness, in inches, for comparison to recommended insulation levels.
  • Check interior walls by looking or feeling for insulation behind an electrical outlet that has had the power to it shut off. You may be able to use a hook or other tool to remove a small piece of insulation for identification. Measure the thickness, in inches, if possible. Check insulation behind all the outlets in your house.
  • Check for uninsulated or minimally insulated areas such as crawl spaces, garage or basement walls, or similar spots. Consult with your HVAC expert to determine if putting insulation in these areas would be of benefit.
  • Once you have a good idea of the status of insulation in your home, ask your HVAC contractor for help or consult the Department of Energy’s online resources for more information and suggestions.

Other Areas to Insulate

  • Attic: Uninsulated attics can get extremely hot during the summer, which increases temperatures throughout your home. They can be a source of heat loss in the winter. Insulate the attic floors, walls and ceilings to prevent these problems. If blanket insulation is impractical, spray foam or loose fill insulation may be the better option.
  • Ductwork: The ductwork of your HVAC system can allow significant amounts of heating and cooling energy to escape through the relatively thin metal of the ducts themselves. Add rigid fiber board insulation to HVAC ductwork to reduce this energy loss and improve HVAC efficiency.
  • Cathedral ceilings: These large open areas are prone to substantial heat loss, so insulating them thoroughly will help keep your indoor temperatures at more consistent levels.
  • Foundation and basement: Insulating these areas will help maintain lower-floor rooms at comfortable temperatures, especially if they don’t receive much heating or cooling from the HVAC system. Proper insulation in these areas can also cut down on moisture problems and reduce the chance of insect infestations. A well-insulated basement, even if it isn’t a finished space, can be more comfortable and useful than one that is uninsulated.

Your local HVAC professional can provide all the information and services you need to install, add to or upgrade the insulation in your home. Contact us today for help finding heating contractors in your area who can provide the advice and materials you need for an effective home insulation project.