What Variables Affect R-Value? What Variables Affect R-Value?
The R-value of your home insulation determines the efficiency of your insulation to resist the flow of heat and cold. As a general rule, home insulation with higher R-values is more suitable for colder climates while lower R-values go well with warmer climates. Many people are not aware of it but changes in the R-value of insulation greatly affect its performance.
The types of material you use to insulate your home greatly affect the R-value of your insulation. Some of the most commonly insulation materials used in homes today are the Fiberglass Insulation, Polyicynene foam, Cellulose insulation and Polystyrene. Below are some of the factors that affect the R-value of each type of insulation.
The fiberglass insulation comes in batts and blow-in types. Batt fiberglass insulation comes in two standard widths and although this type of insulation is quite effective and its R-value is more or less stable, it can be difficult to fit into non-standard spaces. Gaps and cracks around the batts will affect the R-value. Tears and punctures in the batts, as well as crushing of the fiberglass layers, due to improperly handling can also affect the efficiency of this material. However, when properly installed, this type of insulation material can increase the R-value of your walls without making your wall appear thicker or bulkier. On the other hand, the blow-in fiberglass insulation has a lower R-value than the batt type. The R-value of the blow-in fiberglass insulation is affected by its thickness and consistency of the covering. Areas with thinner covering will have lower R-value while areas with thicker covering will have higher R-value.
The Polyicynene Foam
This type of foam has the capacity to expand up to 100 times when applied to walls ceilings and other surfaces. Like the blow-in fiberglass insulation, the Polyicynene foam can effectively seal off your walls, ceilings, floors and other areas in the home so air cannot escape or come in easily. The R-value of this type of insulation is the same as the blow-in fiberglass installation and the factors affecting the R-value of this insulation is more or less the same as that of the blow-in fiberglass. The uneven application of the expandable foam can greatly affect the R-value.
This type of insulation material is made from recycle paper and fibers. Although the Cellulose insulation is environment-friendly, it has a more disadvantages over the fiberglass and the Polyicynene foam. Note that this type of insulation material tends to settle over time and once the material settles you end up with lower R-value. Thickness of the insulation effects R-value even more than density of the material. Moreover, since cellulose insulation is made of paper and fiber, its R-value is drastically reduced when it gets wet. As it is, this type of insulation material is not recommended for sealing off attics and other areas in the house which are prone to flooding or water intrusion.
Normally, the Polystyrene Insulation material has an R-value of 5 per inch of thickness but this value may be affected by a number of factors including handling, installation and use. Nicks, tears and damage on the material due to improper handling will compromise its efficiency.