Thermal insulation is an important feature of any home or business. Apart from drastically reducing heating and cooling costs, it provides a comfortable uniformity in temperature throughout a structure. Different types of insulation have different levels of efficiency when it comes to blocking heat transfer. This efficiency is expressed as the R value of the insulation. High R value insulation is that which blocks heat transfer relatively efficiently, compared to other types of insulation.
The R value is a measure of how well an insulation slows down or blocks heat transfer under specific laboratory conditions. World-wide, the mathematical definition of R value is kelvin square meters per watt. By this calculation, the R value of most insulations is between zero and one.
In the United States, R value is measured with degrees Fahrenheit rather than the kelvin scale. This will usually result in a small whole number for an R value. In general, increasing the thickness of an insulating layer will increase its effective R value. However, it must be taken into consideration that insulation can only block heat loss through walls, floors, and ceilings, but not through window glass or other materials.
Most of the materials typically used to block heat transfer in homes and offices are low R value insulation. This is usually all that is needed, but high R value insulation is also available for certain applications. The insulation with the highest R value is, perhaps ironically, nothing at all. That is to say, a vacuum provides the most ideal insulation. Vacuum insulated panels have an R value of as high as 50, compared to approximately three for conventional fiberglass insulation.
Another high R value insulation is a material known as Aerogel®. It is derived from a gel material and actually consists of more than 99% air in its finished form. It is highly translucent and lightweight, but has impressive insulating properties. Its R value is approximately 10 - not as high as that of vacuum insulated panels, but high enough to make it a type of high R value insulation.
The R value of insulation that each person needs to use in his home or office depends mostly on the local climate, the the type of heating or cooling used in the structure, and other factors. Even low R value insulation can make a significant difference in the efficiency and comfort of a home or workplace. Whatever its R value, insulation should always be installed in such a way to ensure that it performs at its highest potential R value.