In this study, the measured and predicted air distribution of an active chilled beam in a typical office room is described. A free convection model was applied for the vertical downward air jet along the wall by superposing a free convection velocity and an isothermal jet velocity. The velocity and temperature of the wall jet were measured at six different heights and six distances from the wall in the near wall zone and in the wall-floor corner zone. The experiment implemented two airflow rates of 20 and 28 L/s with three cooling loads of 0, 40 and 100 W/m2.

The important error sources associated with measurements using low velocity thermal anemometersincorporating an omnidirectional velocity sensor (LVTA) are identified and quantified. The impact of natural convection, directional sensitivity and dynamic response of the anemometer are modelled. The developed models, together with a database of instantaneous velocity records obtained by means of a Laser Doppler Anemometer are used to estimate the uncertainty of mean velocity and standard deviation of velocity measurements by LVTA.

A study was performed on the effects of porosity on discharge coefficient and airflow characteristics under the condition where uniform approaching flow directly faces to and enters the opening by using wind tunnel experiment and CFD analysis. The evaluation was performed on porosities in the range 0.4% - 64%. The results of wind tunnel experiments suggest that the discharge coefficient increases when the porosity is higher.

The purpose of this paper is to provide a multicriteria approach in order to develop and assess several control methods for hybrid ventilation. This is important because there is currently a great interest in hybrid ventilation as an energy efficient strategy for achieving thermal comfort and good indoor air quality. To reach those targets and manage hybrid ventilation systems, advanced control strategies, based on hierarchical fuzzy controllers, have been developed at the LASH laboratory.

This paper presents the results of tests on the two-zone airflow pattern that forms in a room with displacement ventilation under conditions of various heat sources and airflow rates. The position of the interface layer between the zones was determined experimentally by tracer gas concentration measurement and by applying a plume model for a point heat source. The following heat sources were used: a plume simulator, a desk lamp, a computer, a round plate and a human body. Quasi-laminar diffusers supplied the air.

Several building simulation programs have been developed for design, analysis and prediction of thedistribution of temperature, airflow and heat transfer between the inside and outside of a building, and/or between different zones of the building. These programs are categorized as mono-zone models (e.g. AIDA and Type 19 of TRNSYS), multi-room models (e.g. HOT2000, DOE, Type 56 of TRNSYS, EnergyPlus, COMIS and CONTAMW), zonal models (e.g. POMA and CWSZ), Computational Fluid Dynamics (CFD) models (e.g. EXACT3, FLUENT, FLOVENT, PHOENICS, and STAR-CD), and multi-zone models (e.g. ESP-r).

Wind-induced cross ventilation is one of the key technologies for saving energy while controlling the indoor environment, and seems to be a crucial element of any sustainable building policy. However, it is sometimes difficult to arrange openings on two sides for cross ventilation of a room. In buildings in built-up areas, many rooms only have openings on a single side.

Chenvidyakarn et al (2004a) investigated the natural ventilation of an occupied open-plan space, which was connected to an exterior through two stacks and a low-level vent. Occupants located at an intermediate level between the stacks and the low-level vent acted as a uniform source of heat, providing buoyancy to drive the ventilation. Their work showed that these conditions could produce up to three steady state ventilation regimes. In the first regime, the bottom opening and the shorter stack acted as inflow vents, while the taller stack acted as an outflow vent.

In this study, the function of carbon dioxide as an index of indoor air quality and as a tracer gas to estimate the air exchange rate in naturally ventilated single family houses was investigated. Carbon dioxide concentrations were measured continuously in the occupied room of six selected Irish houses for periods of 2 to 7 days. The air change rates were then calculated according to the mass balance equation and the time variation of carbon dioxide levels.

A method for estimating the time-varying intensity of emitting sources of a gaseous contaminant inventilated enclosures is proposed in this numerical study. A reduced model linking up a set of control points inside the domain to the contaminant sources is identified using the Modal Identification Method, from simulations carried out using CFD software. This reduced model is then used to solve the inverse forced convection problem consisting of the estimation of sources emission rates as a function of time from simulated contaminant concentration measurements.