model validation

Children spend the majority of their weekdays in classrooms that often have low indoor air quality and limited financial resources for the initial and running costs of mechanical ventilation systems. Designing effective natural ventilation (NV) systems in schools is difficult due to the intense use of the classroom spaces and the dependence of NV on building geometry and outdoor conditions. Building thermal and airflow simulation tools are fundamental to predict NV system performance in the design phase.

A literature review has revealed that there is a very limited number of numerical or experimental studies of the air flow for mechanically ventilated large occupied rooms. Existing literature suggests that a room with more than 5 meters floor-to-ceiling height can be considered as a large space. The aim of this paper is to present a set of detailed air temperature and velocity measurements in a large open plan office located in south England.

Meteorological measurements required for the development of a design scheme that responds to the local environment are generally recorded by the weather service in stations that are assumed to be representative of the surrounding region. However, no account is taken of the changes in conditions caused by urban development, even though differences between meteorological conditions within cities compared with adjacent rural areas (the heat island effect) may be substantial.

A summary of the evaluation of an air flow and contaminant model as part of the IEA-ECBCS Annex 23; Mullizone Airflow Modelling' is presented. Evaluation rather validation, is the goal. The most important points of the cases analyzed during this project are presented and commented from the point of view of analytical evaluation, comparison with experimental data and user sensitivity. The conclusion addresses the need for user-friendly tools and guidelines for the analysis of simulation output