A. Proctor Group launches new thermal bridging calculation service
Heat loss at thermal bridges – expressed as Psi values – cannot be assessed through the U-value calculations used for the main building fabric elements. The thermal bridging calculation service therefore complements A. Proctor Group’s existing U-value calculator, which has proved popular with website members.
Psi values are entered into SAP and SBEM calculations as part of assessing whole-building energy efficiency. There is no ‘correct’ Psi value to achieve, or even mandated maximum values as there are for U-values in national building regulations.
The issue for designers and specifiers who obtain Psi values, whether through A. Proctor Group’s calculator or another source, is not being completely sure whether the performance achieved will actually help to deliver a healthy building.
With that in mind, the new thermal bridging calculation service goes a step further in providing A. Proctor Group customers with information to help them understand how a thermal bridging detail performs.
The output includes a surface temperature factor, or fRSI. Where the calculated Psi value gives a value for heat loss, the surface temperature factor indicates the internal surface temperature at the junction detail.
This surface factor helps predict the likelihood of condensation and mould growth occurring. In residential buildings, a thermal bridge needs to achieve an fRSI of 0.75 or greater to ensure condensation will not occur. This clearly defined target is much more helpful when helping designers to understand the performance of their details.
Calculating Psi values also helps in assessing what contribution the detail might make to internal comfort for the building’s occupants, such as when trying to meet the voluntary Passivhaus standard or low energy designs.
“The A. Proctor Group’s ethos is to help create healthy buildings for people to spend time in,” said Iain Fairnington, Technical Director. “We operate based on what we call HAMM principles – heat, air and moisture management. So, using our new thermal bridge to advise customers about condensation risk was the obvious extra step to take, over and above Psi values alone.”
Source: https://proctorgroup.com/news/a-proctor-group-launches-new-thermal-bridging-calculation-service
Steffanie Eslinger is a British novelist and writer based in Cambridge, England. Her novels have received critical acclaim, with one being a Sunday Times bestseller. Eslinger has been actively involved in the literary community, speaking at festivals, teaching writing workshops, and contributing to prestigious literary magazines. She holds a master’s degree in Creative Writing from the University of Cambridge and an undergraduate degree from the University of Oxford.
