Simplify Insulation “R” ratings.
Insulation terms can be quite confusing to anyone outside the industry. If you’ve ever bought insulation for your house, you know that insulation with a high R factor is better. But what, exactly, does that mean? Did you know that the R Factor depends on other factors?
In order to understand the well-known R factor it’s important to understand the factors upon which it relies, the K factor and C factor.
What is the K Factor of Insulation?
The K factor of insulation represents the material’s thermal conductivity or ability to conduct heat. Usually, insulation materials have a K Factor of less than one. The lower the K factor, the better the insulation.
What is the C Factor of Insulation?
The C factor stands for Thermal Conductance Factor. The C factor, like the K factor, is a rate of heat transfer through a material. The lower the C factor, the better the insulating properties of the material. It is the quantity of heat that passes through a foot of insulation material.
The C factor is dependent upon the thickness of the insulation. The thicker the insulation is, the lower the C factor will be and thus the better the material will be at insulating. This is one of the main differences between the K factor and C factor, because generally the thickness of an insulation material will not affect its K factor.
In Australia. We use R ratings and the requirements for higher and higher efficiency increases each year. It is pretty normal to achieve R 3.5 and higher for roof areas and R 2 and higher for walls.
These Ratings are achieved through considering such factors as:
• Roof colour.
• Roof material.
• Eave overhangs.
• Blanket insulation systems.
• Sarking systems.
• Air voids.
• Heat sink materials.
To name a few.
I will look at this issue in more detail over the next few weeks.