Insulator Material Comparison
Whether a house is new construction or an existing home, the proper insulation can make all the difference in comfort, energy savings and other financial benefits. There are many different types of insulation available, and choosing the right one depends on where it will be installed and what R-Value is desired.
R-Value is a measure of how much a particular insulation material resists heat flow. The higher the R-Value, the greater its insulating power. A given R-Value can be achieved with a variety of materials, though some perform better than others. For example, spray foam insulation is generally considered to be the best type of insulation when it comes to R-Value, but the installation method is more labor intensive than other types of insulation.
While a perfect insulator does not exist, a material can be ranked as either a conductor or an insulator.Insulator Material Comparison prevent the transfer of electricity by preventing the free movement of electrons in the material's atoms. In contrast, a conductor allows electric current to easily pass through it.
Some examples of insulators include paper, glass and plastic. These materials have low bulk electrical resistivity, meaning that they do not allow substantial current to pass through them at commonly used voltages. Other materials, such as metals and semiconductors, have high bulk electrical resistance. Insulators are typically made of non-metals because metals tend to have high thermal conductivity, which reduces their insulating capabilities.
The most common form of insulation in homes is fiberglass. This material is inexpensive, lightweight and offers excellent insulating properties. Fiberglass is also fire resistant and does not corrode wires. Other common forms of insulation include cellulose and CMS wool. Cellulose is made from recycled newspaper and offers good insulating value. It is available in loose-fill and wet-spray (used in new construction or gut rehab), as well as in dense-pack forms. Loose-fill cellulose is better than fiberglass at filling small gaps around wiring and joists, while dense-pack can be blown into open walls and attics.
CMS wool is another good insulation choice because it is odorless and has a higher R-Value than fiberglass. It is also a more sustainable option because it is made from recycled cotton and wool. This product is best for use in homes with wood frame construction.
A major concern when selecting an insulation material is its fire rating. Ideally, it should be Class A, which means it is completely fire resistant and will not serve as a catalyst in the event of a fire. Class B insulation, which is less expensive than class A, is also an option, but it will not last as long or provide as much protection.
Other factors to consider when choosing an insulator include its embodied energy. A green construction project should choose an insulator with a low embodied energy, since the energy required to extract, manufacture and transport a given material is considerable. Other important considerations are the vapor barrier and moisture barrier properties of the insulation, which determine how water-resistant it is.