Flow in the plenum of a UFAD system

We describe the flow in an underfloor plenum. We show that the geometry of the plenum causes the flow to exhibit two-dimensional dynamics and to develop flow patterns that are determined by the inlets of the underfloor into the plenum void. We describe laboratory experiments that simulate these flows and also show that the location and number of diffusers in the plenum has little effect on the underfloor flow. Depending on the location of the inlets to the plenum, the flow can exhibit complex vortex patterns and may be time dependent.

Floor-Supply Air-Conditioning System in a Theater Hall

Floor-supply air-conditioning system with Coanda effect is introduced to a theater hall. This system supplies air from floor diffusers set beneath the seat backrest in front of occupants. Supplied air moves upward along the backrest board inducing the circumambient air resulted in airflow temperature difference reduction. Thermal environment was measured under various heat load conditions in the theater hall. Supply air flow along and radiation effect from the seat backrest in front were confirmed using the floor-supply system.

Influence of solar radiation on heat and air flow transfers in double skin facades with venetian blinds.

A comprehensive modelling of a compact double skin facade equipped with a venetian blind is proposed here. The modelling is done using CFD approach to asses the air movement inside the ventilated facade channel and appropriate radiation model for long and short wave exchanges. The impact of solar radiation on temperature and velocity fields as a function of some parameters such as beam radiation incidence angle, blade angle of solar protection, etc. is analysed.

The Role of Indoor Climate in the European Energy Performance of Buildings Directive (EPBD)

From the beginning of 2006 all new buildings (residential, commercial, industrial etc.) must have an energy declaration based on the calculated energy performance of the building, including HVAC and lighting systems. This energy declaration must refer to the primary energy or CO2 emissions. The directive also states that the energy performance calculation must take into account the indoor climate, but gives no guidelines.

Performance Potential of a Whole House Low Energy Ventilation System Predicted from the Outcome of a European Programme of Testing

The problem of achieving good air quality in dwellings whilst saving energy has led to a number of solutions many involving the use of fan power. This paper describes a programme of testing, that has continued over the last three years, of a passive low energy ventilation system. The systems components are supply air window in combination with passive stack vents. Installations have been monitored in unoccupied dwellings in Poland, Denmark and Ireland and user feedback is now being collected, the units now being occupied.

Numerical Evaluation of Wind Pressure Distributions of Buildings by Means of a Modified k-e Model

A modified k-e model that restricts turbulent time scale using Durbin’s limiter was applied for numerical prediction of wind pressure distributions of building models. It is known that the standard k-e model tends to overestimate wind pressure of windward

Experimental Investigation of Three Types of Clean Room Diffusers using Particle Image Velocimetry and Laser Doppler Velocimetry Techniques

The main purpose of this paper is to evaluate the main fluid mechanics parameters in the exit region of three different terminal systems commonly used for controlled environments such as clean rooms or operating theatres. Three different types of diffuser were tested i.e. a diffuser grid, a square ceiling diffuser and a swirling radial discharge diffuser. The paper presents results obtained experimentally which were carried out in order to study the flow characteristics of isothermal jets issuing from such devices.

Sleeping thermal environment and bedroom air conditioning in residential buildings in subtropical areas

This paper presents the results of a study on strategies for bedroom air conditioning in HongKong, a typical subtropical city. It reports firstly on a questionnaire survey on the current situations ofsleeping thermal environment and bedroom air conditioning in residential buildings in Hong Kong. This is followed by reporting results of field monitoring of overnight indoor air temperature, relative humidity and indoor CO2 levels in bedrooms in high-rise residences.

Impact of indoor environment on human health - Egyptian experience -

This study is concerned with the impact of indoor environment on the local National health in airconditioned spaces. The present study is carried out in different applications in Egypt. Two differentmethods are utilized in the present study. An experimental measurement program and comprehensive survey are carried out for some air conditioned applications. The numerical methodsare also utilized to simulate applications that represent the effect of indoor environment onoccupancy health using different indoor air quality indices.

Simple Modelling of Thermal Mass

In this study, the effect of the thermal mass and thermal insulation of a ventilated building onthe indoor environment is investigated. A simplified model of the thermal interaction between a building structure and the interior is developed. Three important parameters are determined, and analytic expressions for the attenuation and phase lag of harmonic external forcing are derived for an unventilated interior. The effect of forced or stack-driven natural ventilation on the interior response is then investigated.

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