R- Values only represent the potential of a materials ability to restrict heat flow. In ICF there are three key factors that enhance the effectiveness of thermal performance.
1. Continuity of insulation- ICF walls have a continuous layer of insulation by necessity as opposed to a traditional stick framed house that has many gaps.
2. Reduced air infiltration- ICF homes consistently show results of 0.15 air changes per hour (ACH) compared to a traditional stick frame house with 0.45 ACH to 1.05 ACH
3. Thermal mass- the mass of an ICF wall acts as a buffer that moderates indoor temperature fluctuations, which reduces peak loads and allows for a decrease in the sizing of HVAC equipment. |