Insulation is a core component of the building envelope, and the amount and type of insulation used in the envelope will directly affect the buildings performance. First one needs to understand what R-value means- and what it doesn’t mean.
Principles of Heat Travel
Heat will travel three different ways, and will always seek cold. All three of these principles of heat travel should be considered when choosing materials for a building envelope. Obviously the product that allows for reducing ALL means of heat travel has a high true insulating value.
Radiation is emitting heat through particles or waves
Convection is the movement of heat through the movement of air
Conduction is the transfer of heat between two materials due to differences in temperature.
R-Value is a measurement of Conduction only
Wall Assembly R-Values Not as They Seem
Batt insulation, while readily available and effective for some uses, rarely will perform at the stated R-Value. Generally speaking, a wall with 2×4 studs and batt insulation (R-19) performs much lower than R-19 due to the extremely lower R-values of wood. Then when you factor in common voids in the wall and the air movement that occurs within a batt insulated wall, now you get a poorly insulated wall. The key is to have continuous insulation throughout the wall.
ICF Wall Assembly
Reward ICFs actually perform to their stated R-values and can easily outperform them due to the other benefits of air tightness and thermal mass you get with insulating concrete forms. Reward’s insulating concrete forms have R-values of 22 and have been shown to achieve performance R-value of 32+. If more insulation is desired per project specifications, the Boost-R Panel is available which will effectively add about R-9, so the ICF R-value becomes an R-30 and has the flexibility to reach R-values of over 50+.