English

Gives the results of an investigation on the combined effect of balcony, opening design and internal division on the indoor airflows pattern of a living zone located on the second floor of a two storey building. It was done using N3S software. The local average velocity coefficient as a function of the position in horizontal sections of 1.00 and 1.50 m in height was used, for activity with sitting and standing positions. The number of measurement points in the living zone were used to calculate the average velocity coefficient.

Describes details of a passive building component consisting of a ventilated roof with a maintained wet lower surface of the cavity over which the external air flows. Numerical simulations were carried out for thermal performance evaluation purposes of the thermal field, flow field and water vapour concentration of air within the duct. Suitable procedures were coded and linked to a commercial program for computational fluid dynamics, in order to obtain an estimate of the thermal cooling flux on the wet surface.

The potential of natural ventilation control techniques when applied to full scale buildings is investigated with the use of both experimental and theoretical tools. An outdoor test cell was used to conduct experiments and two window types (bottom hung and sliding) were tested in different configurations under various meteorological conditions. Describes how theoretical methods for calculating airflow rates through the windows were developed, based on the experimental results and specific modelling activities. On comparison, good agreement was observed.

States that one of the most important parameters for multizone airflow simulation is the wind pressure distribution around a building. Pressure coefficients usually form the input, and the values derives from wind tunnel studies. Alternatives to wind tunnel tests are suggested, namely the use of statistical regression analysis of data obtained from wind tunnel studies. Describes how pressure coefficient values for a shop building were generated using a new wind pressure distribution model based on the regression analysis as well as on wall averaged values from published data.

Describes a simple design tool called the 'office building module' (OPTI), which is intended to help building professionals to incorporate the impact of design choices on energy consumption when designing a project. Emphasises the importance of the program's user-friendliness, minimisation of data and speed. Dynamic thermal programs are needed to compute energy needs and estimate overheating. Current programs suffer from slowness and the need for large amounts of data.

Describes a numerical simulation of carbon dioxide dispersion as a result of occupant breathing in the enclosed space of an auditorium. Considers lighting equipment, number of occupants, two different ventilation systems, air induction and abduction flow rate. Uses three dimensional geometry and turbulence effects.

A field study was carried out to establish the performance of five thermal distribution systems in four large commercial buildings. They were standard single-duct or dual-duct constant air volume (CAV) system and variable air volume (VAV) systems, serving buildings with floor area greater the 2000 m2. Reports the duct air leakage. The ELAs ranged from 0.7 to 12.9 cm2/m3 of duct surface area, and from 0.1 to 7.7 cm2/m2 of floor area.

From the moment that people first settle somewhere, they have been looking for ways to protect themselves from the climate in order to create a pleasant indoor environment. In fact this is still the essential requirement and point of design and construction. In our culture components have been added to the process, the parameters and the possibilities, as a consequence of which the ultimate goal - a comfortable building or building for people - is becoming progressively more difficult.

The double facade is an extra skin around the building giving a cavity between the inner and outer facade. This cavity can be used for the control of the indoor climate. In winter solar energy absorbed by the blinds in the cavity and the heat losses through the internal facade can be used to preheat the ventilation air and can then be compared with the heat recovery unit in a mechanical ventilation system. In summer solar heat gains can be reduced by the effective sunshading system in the cavity. Then unwanted solar radiation is removed by natural ventilation in the cavity.

The first article described the second skin facade in relation to other types of facade such as the modern single-shell glass facade (curtain wall) and the climate-control facade. Various versions of the second skin facade were also discussed. This second article is a more in-depth look at the facade in relation to interior climate and air conditioning plants, and at construction dimensions for the second-skin facade.