modelling

In order to determine whether high outdoor ozone concentrations are transferred to the indoor climate of museums, a monitoring project was carried out on eleven museums, art galleries, historical houses and a museum library for 38 days over the summers of 1984 and 1985. The differences in indoor ozone levels between the buildings could be explained by differences in building and ventilation system design, and this was verified by a mathematical model. Peak indoor ozone levels were highest in building with no air conditioning but a high rate of air exchange with the outdoors.

A model-based technique is described to raise the level of sophistication of building automation systems (BAS). Models are derived using stochastic multivariable identification, and describe the behaviour of air temperature and relative humidity in a full-scale office zone equipped with a dedicated heating, ventilating and air conditioning plant. The models give good accuracy. Investigates the usefulness of the models for facilities management. The 'temperature' model demonstrated substantial improvement of temperature regulation and reduction of energy consumption.

Ventilation effectiveness is an important means to describe and evaluate the performance of a ventilation system. In terms of ventilation tasks, this paper presents a unified physical model for the ventilation efficiency scales based on conservation principles to which a ventilation system should conform. Transport equations for the local mean age of air and contaminant are respectively obtained, which can be integrated solved by the CFD program. To validate the proposed model and CFD simulation of the ventilation efficiency, a 2-D laminar ventilation flow is analysed.

Decision about the use of natural, mechanical or hybrid ventilation system in a building should be taken at the early stages of the building design. While for a mechanical system the decision may be taken on the grounds of purely deterministic procedures, the use of natural forces requires a different approach. Therefore, a simple tool is needed which, given a few important and readily known building parameters and information about the local outdoor climate, enables the designer to determine the most suitable ventilation system.

This paper justifies the need for an integrated approach to building performance assessment and provides examples of the technical appraisals that may then be enabled. The contention is that the use of design tools which focus on a single domain will result in sub-optimum design solutions in terms of indoor air quality, occupant comfort, energy use and environmental impact.

The purpose of this article is to evaluate the performance of an irregular grids finite volume method described in previous article with the use of standard test problem. In this regard, lid-driven cavity and skewed cavity flow have assessed the accuracy of the algorithm. The ability of the method to handle complex geometry is illustrated through some examples of airflow distribution in buildings with complex geometric configuration.

An irregular grids finite volume procedure is presented for flows in complex geometries. The technique carried out computation in the physical plane itself, without any coordinate transformation. Equations are written in Cartesian velocity components and are discrete in physical domain using a cell-centred, staggered grid finite volume method. It is shown that the present formulation ensures that computational scheme is diagonally dominant.

The paper simulates the airflow and temperature fields in a dome Shanghai International Gymnastics Center (SIGC) at one summer day with the computational fluid dynamics (CFD) software PHOENIS. The comparisons of indoor vertical temperature distributions show that the predicted results are in good agreement with the on-site measured ones. And some analyses on the thermal characteristics in the actual dome are carried out.

This paper presents a stochastic single zone model for a hybrid ventilated building. Wind pressure and stack effect are used to drive air through the enclosure assisted by a fan in case of insufficient natural driving forces. Based on Monte Carlo Simulation, the model calculates the time varying airflow rate considering the random nature of input. An important aspect when considering stochastic models for hybrid ventilated buildings is the control strategy. The airflow in the present model is controlled by a damper and a fan using a PI controller.

Describes an assessment using carbon monoxide and volatile organic compounds as IAQ indicators for indoor air quality in a representative underground parking facility. Measurements were made at different time intervals throughout the day. The EMFAC7F1.1 model was used to estimate vehicular emission factors. Concentration profiles were then assembled using a transient mass balance model.