Understanding R-Value vs. LTTR in Polyiso Insulation

Lake City residents undertaking home improvement projects or new construction in the historic downtown or expanding suburbs might encounter terms like "R-value" and "LTTR" when selecting insulation, particularly for polyisocyanurate (polyiso) products. While both relate to insulation's thermal performance, understanding their differences is key to making informed decisions for energy efficiency.

R-value is a common measure of thermal resistance, indicating how well a material resists the flow of heat. A higher R-value generally means better insulating properties. However, for polyiso insulation, the R-value can change over time due to the diffusion of blowing agents from the foam cells.

This is where Long-Term Thermal Resistance (LTTR) comes in. LTTR is a standardized method developed to provide a more accurate, time-averaged R-value for polyiso insulation over its expected service life. It accounts for the gradual reduction in thermal performance, offering a more realistic representation of the insulation's effectiveness over the long haul.

For homeowners and contractors in Lake City, focusing on the LTTR value when purchasing polyiso insulation ensures that the chosen product will deliver its promised energy savings not just initially, but for years to come, especially in our hot, humid climate. This can lead to more consistent utility bills and a more comfortable home environment.