thermal bridge , także: cold bridge

Special attention is given to eliminating thermal bridges.

Since heat flows through the path of least resistance, thermal bridges can contribute to poor energy performance.

Thermal bridges are points in the building envelope that allow heat conduction to occur.

Some forms of insulation transfer heat more readily when wet, and can therefore also form a thermal bridge in this state.

Construction with steel framing contributes to thermal bridges between the outside environment and interior conditioned space.

Moisture can also drastically reduce the effectiveness of insulation by creating a thermal bridge (see below).

In physics, is the heat loss due to linear thermal bridging when calculating the energy performance of buildings.

Concrete balconies that extend the floor slab through the building envelope are a common example of thermal bridging.

When a thermal bridge is desired, it can be a conductive material, a heat pipe, or a radiative path.

Dimensional lumber is commonly used but creates thermal bridging and lowers insulation values.

As U-values falls (see table) and airtightness levels increases, heat loss through thermal bridges becomes less significant.

Metal ties in cavity walls are another type of thermal bridge commonly found in masonry construction.

The calculation of the heat loss due to linear thermal bridging is relatively simple, given by the formula below:

Heat loss due to linear thermal bridging

Non-repeating thermal bridges - such as the bridging of a cavity wall by a single lintel

Thermal bridge concept and interior insulation

Passivhaus Institute: Thermal Bridges in construction - how to avoid them

All constructional wood elements are fitted with a heat-insulation layer put together at the factory - this reduces thermal bridges.

In many older properties, elements such concrete beams or lintels act as thermal bridges providing poor insulation which need to be insulated.

which focus on way of limiting air leakage and thermal bridging in construction.

Insulation requirements relating to thermal bridging

A significant feature of ultra-low-energy buildings is the increasing importance of heat loss through linear thermal bridging within the construction.

Thermal bridges can also be created by uncoordinated construction, for example by closing off parts of external walls before they are fully insulated.

Thermal bridging

Online Energy2D simulation of thermal bridge (Java required)