This paper proposes a new ductless air supply system with a ceiling plenum chamber using low temperature air as a secondary HY AC system for an ice thermal storage system. The proposed air supply system mixes low temperature air with return air from a room using a mixing fan unit (MFU), pressurizes a plenum chamber with the mixed air and supplies the air to the occupied room from diffusers on the ceiling.

Scale model experiments make it possible to analyse design concepts of ventilation, especially air distribution in large enclosures. The airflow structure similarity is fulfilled when experiment is carried out according to the principles of the approximate scale modelling. Special attention should also be paid to proper simulation of boundary and initial conditions. In a real ventilated object, the air is supplied with standard diffusers equipped with deflecting vanes.

The behaviour of room airflows under fully turbulent conditions is well known both in terms of experiments and numerical calculations by computational fluid dynamics (CFD). For room airflows where turbulence is not fully developed though, i.e. flows at low Reynolds numbers, the existing knowledge is limited. It has been the objective to investigate the behaviour of a plane isothermal wall jet in a full-scale ventilated room at low Reynolds numbers, i.e. when the flow is not fully turbulent. The results are significantly different from known theory for fully turbulent flows.

The keeping of animals in livestock buildings requires the ventilation of these buildings. On the one hand good climatic conditions for the animals in the livestock building have to be provided, on the other hand the emissions have to be kept at a low level. The airflow through the livestock building plays an important role for both opposing requirements. The targeted control of the climate in the livestock building and for the minimization of emissions calls for knowledge about airflow and emission streams.

In this study the instantaneous temperatures and velocities close to a diffuser for displacement ventilation have been recorded by using whole-field measuring techniques. The air temperatures were measured indirectly by the use of a low thermal mass screen in conjunction with infrared thermography. The measuring screen was mounted parallel to the airflow, acting as a target screen. By using the thermal images the size of the near zone was also calculated. To determine air movements a whole field method called particle streak velocimetry (PSV) was used.

Presented in the paper is an efficient and accurate numerical method for simulation of ventilation duct flow. The mathematical method is based on the three-dimensional incompressible RANS equations with isotropic k-w near-wall turbulence closures, written in generalized curvilinear coordinates in strong conservation form. The numerical method presented here is used to calculate the turbulent flow through a bend of rectangular ventilation duct featuring pressure induced secondary motions and rotation effects on turbulence.

The aim of this study is to improve the utilization of CFD approach in the applications of air conditioning technology. More precisely, to establish principles and recommendations to follow in order to design air distribution systems in small enclosures at low room air changes per hour by means of CFD technique. By the use of a commercial code, Fluent, the accuracy and reliability of such a numerical simulation are elucidated in this work for a mixing ventilation system; the air supply terminal is a commercial diffuser which creates a complicated 3D - wall jet below the ceiling.

In order to simulate indoor air distribution and airflow around buildings quickly and accurately by CFD (Computational Fluid Dynamics) technique, a new zero-equation turbulence model and momentum method for inlet boundary condition are adopted. The new version of STACH-3, a three-dimensional CFD software is developed based on these. An example for outdoor airflow around an isolated building is given as well. For those high-density buildings with complex geometry, the TSM (Two Step Method) is proposed.

The effect of the change in object positions (i.e. office furniture) on the air quality in a room was studied using zonal purging flow rates. In relation to the zonal purging flow rate in a room, the transfer probability from the inlet to a certain zone can provide information on the amount of fresh air from the inlet to the zone. In this study, the probability obtained from Markov chain theory was used to analyze the ventilation performance.

In order to quantify uncertainty in thermal building simulation stochastic modelling is applied on a building model. Part l deals with the stochastic thermal building model and a test case. This paper deals with the determination of the stochastic input loads. The importance of obtaining a proper statistical description of the input quantities to a stochastic model is addressed and exemplified by stochastic models for the external air temperature and the solar heat gain.