THERM8.0

THERM 8.0 is a two-dimensional heat-transfer analysis tool developed by Lawrence Berkeley National Laboratory (LBNL) for evaluating the thermal performance of building envelope components. Using finite-element methods, it models conduction and predicts temperature fields, heat flow, and surface temperatures in cross-sections of products such as windows, curtain walls, doors, skylights, and wall assemblies. Practitioners use THERM to estimate U-factors and linear thermal transmittances (psi-values), assess condensation risk, and design effective thermal breaks and spacers. When paired with LBNL’s WINDOW software, it supports standardized whole-product ratings and procedures commonly used in industry, including those associated with NFRC methodologies. The software produces clear visual outputs—such as isotherms and heat-flux vectors—along with detailed numerical results to guide product development, certification, and research.

Key capabilities:

• Finite-element 2D heat-transfer modeling for complex geometries and materials
• Calculation of U-factors, psi-values, surface temperatures, and heat flux
• Visualization of isotherms and heat-flow vectors to diagnose thermal bridges
• Material libraries and user-defined properties, with configurable boundary conditions
• Integration with LBNL’s WINDOW for whole-assembly performance metrics
• Designed for manufacturers, façade engineers, energy consultants, and researchers
• Windows-based desktop application

THERM8.0 is developed by LBNL. The most popular version of this product among our users is 8.0.