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In most countries nowadays, concepts of climatization and natural ventilation are considered essential aspects of any building project. However they are also used to ensure indoor air quality and summer thermal comfort. There are many other advantages to be gained such as reductions in energy use and noise levels and easier plant maintenance. In recent years, hybrid ventilation systems in office buildings have been used increasingly.

The Field Museum is a world-renowned natural science institution. It is housed in an 84,000 m 2 building constructed from 1917 to 1921. Housed in the building are scientific laboratories, specimen preparation facilities, resource centers, over twenty-one million specimens, public exhibits, educational venues and lecture halls, administrative areas and restaurants. This paper presents the approaches used by The Field Museum to bring itself forward into the 21 st Century. The process started in 1993 and includes significant modifications/ replacement/modernization of the HVAC systems.

This research is based upon an examination of the natural cooling of the large reading room of the Bernardini(tm) Library in Lecce, Italy. The library is contained in an old building which is currently under restoration. Both indoor and outdoor temperatures as well as relative humidity were monitored, so that the most appropriate system to cool the library's large reading room in summer could be selected. The external walls were endoscopically investigated. Air is supplied by a displacement ventilation system and a system of buried pipes has been designed.

The purpose of this study is to evaluate the use of mechanically driven night ventilation in a small bakery shop by looking at the indoor temperature reduction and energy savings produced by the reduction of the cooling load of air conditioning systems. The results from simulations using a validated model based on the TRNSYS simulation environment demonstrate that night time ventilation can reduce peak daytime temperatures in shops without air conditioning. Where a shop has air conditioning, ventilation at night can reduce the cooling load of the air conditioning system.

The paper presents a way of producing an algorithm for the automated construction of mathematical models of air conditioning and ventilating systems with branched air duct networks. The use of mathematical modelling in making aerodynamic calculations of air duct networks allows us to determine the actual value of air flow in network elements. It also permits us to achieve the required air flows effectively in the adjustment of a system.

The purpose of this paper is to improve our understanding of the transient behaviour of airing by window opening. While a few simple models exist to analyse the results of window opening, its transient behaviour is not yet well understood, in its effects on air change rates, air temperature and ventilation efficiency. The paper achieves its purpose in the first place by using a synthesis of numerical modelling activity. Then a critical analysis of the methods of calculation is undertaken, comparing both detailed (CFD) analysis results and simplified or zonal models predictions.

Describes a study based on experimental work carried out in the full-size MiniBat experimental cell, comprising two zones separated by a wall and a door. Experiments were carried out in a steady state, under isothermal and non-isothermal conditions, with a heating system and a manikin. To determine ventilation effectiveness the tracer gas method was used. It was injected into zone 1 and two positions were examined. The study concluded that the heating system favoured the mixing of the air in the cell, which means that the ventilation effectiveness was always close to one.

Aims to study the behaviour of airflow generated by multiple jets and introduced into a room. A finite volumes mathematical model was used in the study, in which the equations were linearised in implicit form and the domain was presented in its discrete elements using the finite volume method. The numerical simulation was performed by creating unstructured computational grids. Findings were compared to experimental data including an extensive series of measurement taken in a model environment setup in a laboratory.

To simulate non-isothermal indoor airflow more quickly and correctly, a turbulence model is performed in STACH-3, the 3-D CFD code developed by Tsinghua University. Validation reveals that it is satisfied for non-isothermal indoor airflow. The air distribution in an actual conference room with VAV system is numerically solved by CFD method, and the conventional jet theory method is used for a comparison of the results. Subsequently an analysis is done of the cold air draught and hot air climbing problems.

The article presents a zonal model called Sim_Zonal which can be used to predict air movement, temperature distribution and comfort characteristics in a room. The model is based on an approximate partitioning of the room, which is divided into a small number of 'cells', usually in the order of 10 to 100, as compared to 10000 or more for typical CFD calculations. Exchanges are calculated between the cells when mass balance and heat balance equations are applied. Empirical laws describe airflow where plumes or jets occur.