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Last edited 26 Jul 2022
In terms of building design the Psi or Ψ value is the property of a thermal bridge junction between two elements and expresses the rate of heat flow per unit length of at thermal bridge. It might be considered as an adjustment figure for performance and is considered when calculating or allowing for U values and het loss in building fabric.
Psi should not be confused with PSI, which might also be found in the construction field and stands for pounds per square inch (PSI). PSI is a measurement of pressure in the Imperial system of measurement, commonly used to measure the pneumatic pressure of gasses or the hydraulic pressure of liquids. PSI is also used as a measure of tensile strength, as a resistance to pulling forces, and elastic modulus strength, defined as resistance to deformation ie the stiffness of materials.
- Air tightness in buildings.
- Cavity wall insulation.
- Computational fluid dynamics.
- Computational fluid dynamics in building design: An introduction FB 69.
- Conventions for U-value calculations (2006 edition) BR 443.
- Floor insulation.
- Heat transfer.
- Insulation specification.
- Limiting fabric parameters.
- Linear thermal transmittance.
- Roof insulation.
- Solid wall insulation.
- Standard Assessment Procedure SAP.
- Thermal admittance.
- Thermal bridge.
- Thermal mass.
- Thermographic survey.
- U value.
- U-value conventions in practice: Worked examples using BR 443.
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