Comparison of coupled and decoupled solutions for temperature and air flow in a building

This paper concerns modelling and simulation of coupled heat and air flow in buildings. A brief overview of the current state in modelling this issue is included. Starting from a zonal mass balance approach, the paper describes a method used for the simultaneous solution of the associated non-linear equations, and the solution coupling of the heat and mass conservation equation-sets. By means of a case study involving a case of strongly coupled heat and air flow, this paper aims to quantify the differences - in terms of accuracy and computer resources - resulting from coupled and de-coupled solution methods. The main conclusion from the case study is that the coupled solution method will be able to generate accurate results, even with simulation time steps of one hour. Reducing the time step will increase the computing resources used considerably, with a relative small improvement in the accuracy. For equal length of time step a coupled solution method will use more computer resources ...