Energy efficient room air distribution.

An environmental chamber has been used to compare the effectiveness of mixing and displacement ventilation in terms of heat and contaminant removal. Results are presented for CFD simulations of the air movement in the chamber and for measurements using a heated mannequin with displacement ventilation. The CFD simulations and the measurements suggest that displacement ventilation is more energy efficient than a mixing system.

Individual air distribution control panel on partition panel at personal task area.

A general trend in intelligent buildings is the decentralization of environmental controlsystems. Decentralized environmental control systems have many advantages over centralizedsystems. In order to filly utilize a decentralized control system, the control zone should becompletely individualized so that one occupant can feel free to adjust the air volume andtemperature without being concerned about affecting the comfort of other occupants. Afurniture integrated air distribution control system can provide highly individualizedenvironmental control.

Experimental and numerical investigation on temperature and air velocity distribution in a room equipped with split-system air conditioner.

Split-system air conditioning is increasingly usedapplications, owing to its low cost and installationboth for residential and commercialease. The indoor split-system unit iscommonly of the wall-mounted type and, due to its dimensions and position, very often itgives rise to appreciable air velocities and temperature gradients in the occupied zone of theroom. This work reports and discusses some experimental data collected in a test room withwall-mounted indoor unit, under different operating conditions.

Comparison of room airflow characteristics in a full scale environment chamber with cold air distribution.

This paper discusses the experimental study of direct delivery of cold air into a full scale environmental chamber using different diffusers, i.e. a multi-cone circular ceiling diffuser, a vortex diffuser and a nozzle type diffuser. Comparisons have been made of the following: mean flow patterns, temperature distribution and condensation risk. The vortex diffuser exhibits a higher induction effect than that of the nozzle type diffuser. However, the air speed generated by the vortex diffuser is generally lower than that of nozzle type diffuser.

Improvement of a plume volume flux calculation method.

The paper presents the results of the research on application of the equation describing the increase in the air volume flux in buoyant plume above a point heat source to calculate plumes in rooms with displacement ventilation.The tests carried out in test room have given information about practical defining of the distance from the origin, assuming entrainment coefficient values and possibilities of assuming equal widths of temperature and velocity profiles in order to determine the origin distance.

Numerical modelling of surface condensation on diffuser for cold air distribution systems.

Condensation on the surfaces of diffuser and cold air dumping are the two major concerns in the application of cold air distribution brought about by the high temperature difference between supply air and room air. Condensation will form if the surface temperature of the diffuser is lower than the dew point temperature of ambient air. The presence of surface condensation can promote growth of unhealthy and smelly mold, and produce unwelcome damage of a structural and/or aesthetic nature. Cold air dumping is a major factor that detracts from thermal comfort in an airconditioned room.

Underfloor air distribution solutions for open office applications.

The use of raised access flooring systems for office environments has become much more frequent in recent years. Power and data cables housed in the floor cavity can easily be accessed and modified to accommodate changes in the occupancy and use of the space. This cavity can also be used as a supply air plenum, which allows introduction of conditioned air through the floor.

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