
Coupling Coefficients and Precision reportThe Coupling Coefficients and Precision report displays the matrix L_{i,j} of thermal coupling coefficients (L^{2D} or L^{3D} , also called heat transfer coefficients H in some standards or Leitwert matrix, thermal conductance matrix) and respective precision information of the simulation. Depending on which problems have been chosen for the Solver and on the number and type of boundary conditions following results are shown:
for the steady state (stationary) heat transport problem:
for the steady state vapour diffusion problem:
for the dynamic, transient, harmonic, periodic heat transport problem, for any period length (and eventually higher harmonics):
given as complex numbers and as amplitude/phase pairs. If the number of matrix columns output shall overrun the page width then the output of overrunning matrix columns is continued in groups one below the other. Steady state (stationary) thermal coupling coefficientsThe report displays the matrix of thermal coupling coefficients for any pair of spaces (with 6 decimal places). If N spaces are attached to the considered construction the NxN matrix will be displayed (without diagonal elements). Theoretically the matrix shall be symmetrical (i.e. L_{ij}=L_{ji}), thus the output allows precision consideration of results. These values are used, for example, to calculate thermal bridge correction factors  for a 3D case the "point thermal transmittance" Χ (Chi) and for a 2D case the "linear thermal transmittance" Ψ (Psi). Remark: By multiplying the (steady state) thermal coupling coefficient L_{ij} by the difference of temperatures of respective space pairs Θ_{i}−Θ_{j} one will receive the heat stream (or the length related heat stream in 2D case) between the two spaces transmitted through the modelled component. Heat source Distribution Factors (steady state)In the event heat sources are available also, the heat distribution factors of each source to all spaces are shown too. If N spaces are attached to the considered construction then there will be N numbers shown for every heat source in the distribution table. The ith (i = 1,N) column value of the distribution table shows the percentage of the heat provided by the particular heat source passing to the ith space. The values of the distribution table are therefore from the range 0 to 1. Because the steady state calculation does not cover the heat capacity storage, the sum of all distribution values must theoretically result in 1 (apart from minor rounding errors) allowing further precision consideration of results. Remark: By multiplying the distribution factor F_{kj} by its respective power density Φ_{k} of the heat source k and its volume V_{k} one will receive the heat stream (or the length related heat stream in 2D case) from the heat source k to the space j. (The volume of every heat source will be shown within Modelling report or Results report). Transient (instationary, dynamic), harmonic, periodic thermal coupling coefficientsProvided the solution of a dynamic, transient, harmonic, periodic problem has been computed also, the matrix of periodic harmonic coupling coefficients will be output (with output of up to 4 decimal places). The output is provided for each requested period (period length, in decreasing order; longest first) once as matrix of complex numbers and additionally as matrix of norm (amplitude) and argument (phase shift, time lag) values. Diagonal elements (contrary to the steady state case these are significant and output here) can be used for the calculation of effective heat capacities. Theoretically, as for the steady state case, the matrix shall be symmetrical, thus the output allows precision considerations of results also. In the event heat sources are available also, the harmonic heat distribution factors of each source to all spaces are shown too. Vapour diffusion, hygric coupling coefficientsThe report will also show hygric coupling coefficients (mg/Pa*h) ("Matrix of hygric coupling") if there are results of vapour diffusion calculation available too.
Precision informationAn immediate indicator of the precision of the solutions is the matrix of thermal coupling coefficients itself  if it is not reasonably symmetrical, then further calculation might be necessary. Along with the output of coupling coefficients the necessary information about the precision of these results is output. A theoretically exact method of calculation would necessarily satisfy the condition, that the sum of heat entering a component exactly equals the sum leaving the same  for any set of basic solutions. The inherent nature of a numeric method, however, will always result in a marginal difference in the evaluated energy balance. This is referred to here as the closeup error of base solution. Dividing the closeup error by the sum of the coefficients associated with the respective base solution (space) provides a measure of the precision of calculation.
The relative closeup error shall never exceed 10^{−4} considering precise solution (see EN ISO 10211:2008). The value of the Relative CloseUp Error limit (default 10^{−4}) can be adjusted within application settings:
A warning message "(*) Warning: The precision criterion concerning the magnitude of relative closeup errors is not fulfilled" will be shown below the precision data listing if the precision criterion is not satisfied by any of base solution (the display of this message can be turned off by the application setting "Relative CloseUp Error  Warn if above"). Note: If the relative closeup error exceeds 10^{−4} (or the limit otherwise set) a continuation of calculation based on more stringent parameters for more precise solution should be considered before proceeding with further evaluation. Eventually modified (finer or coarser) raster discretisation (gridding) might be required also.
If the solution of vapour diffusion has been also computed, the associated precision information is also displayed following the results of thermal heat calculation. Precision indicators, i.e. (*), (**) and a warning message, are shown for the vapour base solutions  based on same precision criteria (see above). A report can be:
See Toolbar of a Report window See also: Evaluation windows, Evaluation and Results, Toolbar of a Report window, Results 3D window, Boundary Conditions window, Please Wait window, PsiValue Determination (Calculate ΨValue), Linear and Point Transmittance, EN ISO 10211 
