What is considered the most important factor in determining the "R" value of blown-in insulation?

The "R" value of blown-in insulation is a measure of its thermal resistance, or how effective it is at insulating a space. Density is the most important factor in determining this value because it directly influences the insulation's ability to trap air, which is crucial for its insulating properties. Higher density materials can contain more air pockets, leading to improved insulation performance. This means that for a given thickness of insulation, a denser material typically has a higher R value, making it more efficient at resisting heat flow.

Other factors, such as thickness and material type, certainly play a role in insulation performance, but density has a more significant impact on the ability of the material to resist heat transfer. For instance, while increasing thickness can enhance insulation, if the material lacks sufficient density, it may not perform well. Similarly, while different materials can offer varying insulation properties, it's the density of those materials that primarily determines their effectiveness. Air permeability is also relevant since it influences how well insulation can hold in the air, but again, density is the key determinant of the R value. Understanding this relationship is crucial for making informed choices about insulation products in construction and renovation projects.