A thermal bridge occurs when a non-insulating material passes through a building’s insulation, causing uneven surface temperatures. Corners, windows, roofs, and walls are common places for thermal bridges. They can lead to condensation, mold growth, and energy inefficiency. Design and construction practices can minimize thermal bridges, and infrared imaging and computer analysis can detect them.
A thermal bridge occurs when a component made of a non-insulating or thermally conductive material passes through the insulating envelope of a building. Heat will be transferred at a faster rate across this bridge than heat in the surrounding areas. This compromises the expected performance of the insulating material and results in uneven surface temperatures. A thermal bridge is sometimes referred to as a cold bridge.
There are many places within a building where a thermal bridge is likely to occur. Corners and seams of windows and doors, where walls and roofs meet, and wall interfaces are particularly prone to this problem. Structural elements that are assembled during construction may produce a thermal bridge due to the components used in joining the elements. Even ventilation devices and balconies can penetrate the insulating layers.
The effects of a thermal bridge are, in general, inversely related to the quality of the insulation and the energy performance of a building. The relative amount of heat transfer due to bridges is relatively low in buildings where thermal protection was not a major factor in the design or was poorly implemented. In modern buildings, where there is a premium for efficient use of energy, thermal bridges can be the major factor in unwanted heat transfer.
Heat transfer resulting from a thermal bridge is more of a concern than just the efficiency of indoor climate control. A consequence could be a lower internal surface temperature. This can lead to condensation problems in corners and at the joints between floor and wall, particularly in humid climates. Moisture buildup can directly lead to mold growth and can go unnoticed if it occurs on unexposed surfaces.
Design and construction practices have been developed to minimize heat transfer due to thermal bridges. Care must be taken that wall ties and mechanical joints of structural elements do not penetrate a cavity wall or insulating casing. It is possible to avoid the extension of the floor beyond the envelope, exposed lentils and the use of concrete or steel elements which are combined in the external walls. The joining of two planes, such as walls and corners, can be made thermally more reliable by choice of materials and mounting methods.
The use of infrared imaging to detect erratic surface temperatures indicative of a thermal bridge has become common. Three-dimensional computer analysis of heat flux in building construction elements has also become a powerful tool. This software extends the one-dimensional models that have traditionally been used to estimate the thermal properties of buildings.
Protect your devices with Threat Protection by NordVPN
