📊 Results

Visualize temperature distributions, compute thermal performance metrics, and analyze condensation risk.

Temperature Color Map

After a successful solve, the canvas displays a continuous temperature color map rendered via PixiJS v8 with WebGL. Nodal temperatures are interpolated across each triangle using the FEM shape functions — the result is a smooth, high-fidelity visualization even with coarse meshes.

Isotherm Contour Lines

Isotherm lines connect all points at the same temperature. ThermX computes them using a marching algorithm on the triangulation — lines pass through triangle edges at interpolated positions, giving smooth, accurate contours.

Heat Flux Vectors

The heat flux field q = −λ∇T is computed at each triangle centroid and displayed as vector arrows. Arrow length is proportional to flux magnitude; arrow direction indicates heat flow direction.

Computed Metrics

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U-factor (Thermal Transmittance)
ISO 15099

The overall heat transfer coefficient U [W/(m²·K)] is computed by integrating the total heat flow through selected boundary surfaces and dividing by the temperature difference and cross-section width. Use the U-factor panel to select which boundary surfaces to include in the calculation.

Ψ
PSI-value (Linear Thermal Transmittance, Ψ / L2D)
EN ISO 10211

The PSI-value (Ψ) quantifies the additional heat loss per unit length due to a thermal bridge, compared to the 1D (clear-field) U-values of the flanking components. Computed as:

Ψ = L2D − Σ(Uj × lj)

where L2D is the total 2D heat flow per unit length, Uj is the U-value of each flanking component, and lj is the length of each component in the cross-section. The Component Editor lets you define and edit the flanking components (their 1D U-values and lengths) interactively.

💧
fRsi — Condensation Risk Factor
EN ISO 13788

The temperature factor fRsi is a measure of the minimum surface temperature relative to the boundary conditions:

fRsi = (T_si,min − T_e) / (T_i − T_e)

A higher fRsi indicates lower condensation risk. The critical point — the surface location with the lowest temperature — is marked on the canvas with a marker. For certification, fRsi must exceed 0.70 (EN ISO 13788).

Results Panel Overview

ResultTogglePanel location
Temperature mapAlways on after solveCanvas overlay
IsothermsOn/Off + interval controlResults → Isotherms
Heat flux vectorsOn/Off + scale controlResults → Flux
U-factorAuto-computedResults → U-factor
PSI-valueComponent editorResults → PSI
fRsiAuto-computed + markerResults → fRsi
Materials legendOn/OffCanvas overlay

PSI Component Editor

The PSI-value calculation requires defining the flanking components that bound the thermal bridge cross-section. Use the Component Editor to:

  1. Add components (e.g., "Wall", "Floor slab")
  2. Specify the U-value (W/m²·K) for each component's 1D clear-field construction
  3. Specify the length (m) of each component in the cross-section
  4. ThermX computes Ψ = L2D − Σ(Uj × lj) automatically
Standard Reference

PSI-value computation follows EN ISO 10211:2017. U-factor calculation follows ISO 15099:2003. Condensation risk (fRsi) follows EN ISO 13788:2012.