Laplace and State-Space Methods for Calculating the Heat Losses in Case of Heavyweight Building Elements and Short Sampling Times

Reducing heat losses through the building envelope is one of most important aspects to be met if targets set by European Union are achieved. In order obtain a more realistic energy demand, dynamic transfer simulations used calculate consumption buildings, since steady-state calculations do not take into account thermal mass in buildings. These employ methods based on analytical models numerical unsuitable for longer time periods. The herein fall category conduction functions (CTFs). Two computing CTFs that addressed this research Laplace method and State-Space method. objective paper verify efficiency calculating demand case heavyweight elements shorter sampling times, provide means improving algorithms these methods. were implemented Mathematica, results compared EnergyPlus TRNSYS, which use similar demand. It was shown wall element step 0.25 h, difference between total transferred inner surface about 31% 78% TRNSYS reference solution. For lightweight element, stable but 0.1 differences 45.64% 303% EnergyPlus, solution, respectively, maximum 12.03% with h. While better than boundary conditions, they also have their limitations could lead unsatisfactory short times applied properly.