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Thermal Modelling

Building regulations now require that thermal bridging be taken into account for new residential & commercial buildings as more stringent criteria on increasing insulation levels has increased the importance due to energy loss as a result of thermal bridging.

The calculation of the effect of thermal bridging is known as thermal modelling and uses advanced 2 and 3 dimensional software to calculate the effects of this on the heat loss through these junctions. CERL engineers are very experienced in modelling thermal junctions and are registered with the NSAI approved Thermal Modeller scheme for bridging details and junctions to demonstrate compliance with building regulations in Ireland. We conduct studies to calculate the effect of thermal bridges (psi-value) calculations, point thermal bridge (chi-value) calculations and mould growth risk assessments (fRsi-value).

Thermal Bridging

Thermal bridging occurs in building envelopes when gaps or breaks in the insulation envelope create pathways for heat loss to bypass thermal insulation. Thermal bridging also occurs in building envelopes when materials with higher thermal conductivity values are used – like steel, timber and concrete. When these materials are used, they can create pathways for heat to bypass the thermal insulation, as the heat always looks for the path of least resistance.

The heat loss associated with these thermal bridges is expressed as a linear thermal transmittance (Ψ-value). The Temperature Factor (f) should also be calculated to determine surface temperature and the risk of mould growth, which can have significant health implications.

Where details do not conform to Accredited Construction Details, they should be evaluated using thermal simulation software, following agreed conventions and standards.

A typical section of an output report calculated by our engineers: