English

Numerical simulations and computational fluid dynamics can be usefully integrated with architecturalmodelling to provide designers with a powerful single CFD based architectural modelling and designframework. This framework can be interfaced with building thermal performance modelling thus further integrating the full thermal and flow domains within architectural modelling. CFD analysis is generally restricted to the buildings environment flows or indoor single rooms and flow in spaces.

The UK Building Regulations regarding the provision of openings to promote natural ventilation of dwellings were modified in 2006 and, with the increased demand for sealing of structures to prevent the ingress of unwanted air, there is the possibility that under certain design conditions there would be insufficient provision of outside air in the absence of window opening or mechanical ventilation.

Even if there is only one opening within a room and there is no temperature difference between the inside outside, the room will be ventilated by the external natural wind. Two kinds of theoretical approach have tried before to evaluate the mechanisms driving this flow: one is pulsation theory and the other is mixing layer theory. In this paper, these theories are reviewed and the validity of each is examined by means wind tunnel test. Results showed that the pulsation theory was not applicable to all wind directions.

The objective of this study is to investigate how measured ventilation rates in dwellings vary over the heating season in a Nordic climate. The aim is to draw conclusions about the possibility to transform a measurement result obtained during a relatively short period of time into one which would have been expected as an average over a whole season. If such normalisation of measurement data is not possible, dwellings may be misclassified as under- or over-ventilated, a matter which may dilute a possible relationship between health and air quality in epidemiological studies.

Hong Kong’s climate is sub-tropical. It has hot and humid weather during summer and more temperate weather during the winter. The façade accounts for more than 50% of the peak cooling load in office buildings. This makes an integrated façade design important. This paper reports continuing research into optimising the design of a ventilated façade system by controlling the exhaust airflow. The first step was to analyse the ventilation system in a simple office room. This resulted in further integration of a climate responsive façade and an energy efficient MVAC system.

Underfloor air distribution (UFAD) is a new method of supplying heated or cooled air throughout a building. Reported advantages of UFAD include energy savings and improved indoor air quality (IAQ). We measured several aspects of the performance of a UFAD system installed in a medium-size office building. The measured air change effectiveness was very close to unity, which is comparable to that measured in buildings with typical overhead air distribution.

Thermal mass, including the building envelope, the interior partition, the furnishing, or even the air inside building, is defined as the mass that can store thermal energy (heat or cooling energy). For storing heat in buildings, there are two important thermal properties of the materials that need to be considered, i.e. the heat capacity by volume and the heat-absorption rate. The first property determines the ability of the element to store thermal energy, and the second property determines the ability of the element to conduct the thermal energy.

The well-known case of a simple naturally ventilated building with two openings, uniform internal temperature and opposing wind and buoyancy forces is re-visited. In particular, it is shown that the effect of wind turbulence can play a deciding role on whether or not multiple solutions occur. It is also argued that in practice the number of possible solutions is three rather than two.

This paper presents results of CFD simulations of flow around and through a cubic building with symmetric openings on two opposite sides. The case where the incoming wind is perpendicular to the front face of the building, and so parallel to the openings, is considered. An unsteady method, Detached Eddy Simulation, is used to capture the unsteady cross-ventilation.

In this paper experimental results are used to verify and validate a computational fluid dynamics (CFD) model based on a commercial package. The validation is used to ensure that the CFD model is able to simulate stratum ventilation. The low speed air jet is the basis for a newly proposed ventilation mode whereby jets are placed strategically around a room at breathing height level to create a layer or stratum of relatively fresher air.