We talked about air leaks and how air moves throughout the house. We will take a look at what insulation is and how important it is to conservation. Heat transmission in the home is the leading cause of winter heat loss and the loss of cool air during summer months. Most single family homes lose more heat through transmission than they do through air leakage. Insulation slows heat transmission through the home’s floors, walls, ceiling, and roof.
Insulation performs the following thermal actions:
- Conserves energy by slowing heat transmission.
- Reduces the size of heating and cooling equipment that a building needs according to the insulation’s R-value.
- Prevents wintertime moisture by preventing low interior surface temperatures.
Insulation also carries with it the following benefits:
- Reduces noise.
- Helps slow down and prevent air leakage and water vapor transmission.
- Helps improve a building’s fire resistance.
Insulation is installed in a building’s cavities, attached to the building frame, or attached to the building’s exterior surfaces. What are some of the characteristics of insulation? Insulation slows heat transmission in an important way. It reduces heat radiation and air convection within the cavities where it is installed. Insulating materials are not as dense as other building materials which are conductors. There are millions of tiny air pockets within the fibers or bubbles in plastic foam insulation. These fibers and tiny bubbles help to slow down the process of heat transmission. The density of the insulation affects its R-value.
Insulation’s ability to slow down heat flow is measured by the R-value. The R-value of any building assembly is determined by the following factors:
- Type and density of the insulation.
- Air leakage and convection through voids, gaps, or low insulation density.
- Water’s presence within the cavities
INSULATION R-VALUES PER INCH
Fiberglass batts, Blown, Board – 2.6 – 4.2
Cellulose Blown – 3.2 – 3.6
Mineral Wool Batts – 2.6 – 4.4
Vermiculite or Pearlite – 2.1 – 2.4
Expanded Polystyrene – 3.6 – 4.4
Extruded Polystyrene – 5.0
Polyisocyanurate Board – 5.6 – 7.6
R-values vary by insulation type, density, and the quality of insulation.
Insulation plays an important role in energy conservation. You can use all the green material you want to use and seal and caulk every split and crack you can, but if you have no insulation, you have accomplished nothing. When is the last time you have taken a look in your attic? Chances are that if you need to add insulation to your attic, there are other places where it may need to be added, but the attic is the first place to start. You can contact your local contractor for an inspection to see if your insulation needs to be updated.