Title: Thermal Control in Buildings | Building Science Corp
Headings: BSD-011: Thermal Control in Buildings
BSD-011: Thermal Control in Buildings
Abstract:
Background
Insulation
Thermal Bridging
Heat Loss to the Ground
Air Leakage
Solar Radiation Through Windows
Interior Heat Gains
Conclusions
Rights:

Content: Rockwool products therefore tend to use higher densities to achieve the same thermal performance as spun glass. This extra density provides these products with greater strength and more resistance to convection and radiation effects. Even though more material is used for the same thermal resistance, rockwool products compete in applications that require these properties. Figure 3: Comparison of the thickness of various materials required to achieve R20 (RSI3.5). Thermal Bridging
Heat flow deviates from one-dimensional at corners, parapets, intersections between different assemblies, etc. When heat flows at a much higher rate through one part of an assembly than another, the term thermal bridge is used to reflect the fact that the heat has bridged over / around the thermal insulation. Thermal bridges become important when: they cause cold spots within an assembly that might cause performance (e.g., surface condensation), durability or comfort problems
they are either large enough or intense enough (highly conductive) that they affect the total heat loss through the enclosure
Thermal bridging can severely compromise thermal control and comfort in some building types. Heat flow through steel stud walls and metal curtainwalls is dominated by heat flow through the metal components.