PR2008

The hybrid air-conditioning system is consistsof natural ventilation and mechanicalair-conditioning system in this paper. Theairflow characteristics inside office room withdifferent way to introduce the natural ventilationwere analyzed by means of CFD analysis. Theoffice has the same air-conditioning system byUnder Flow Air Distribution (UFAD). Threeways to introduce the natural ventilation wereused in the analyses. Outdoor air is introducedinto office room from Outdoor Air Intake (OAI)on ceiling, outward wall upper window, andfloor.

In this paper we analyze by means ofbuilding simulation the effect of differentparameter combinations on the non-heating andnon-cooling temperatures of a typical airconditionedoffice building.

The aim of this study is to examine contaminantdistribution in the occupied zone of a room servedby a novel enhanced displacement ventilationsystem which brings cooler air near the floorupward around human body via 4 fans mounted ateach corner of a chair. An office with twoworkstations was simulated in a full-scale testroom. The discharge angle of the flow from thefans was varied to be 0, 30, and 60" from thehorizontal plane. Two breathing thennal manikinswere used to simulate the occ~~pantwsi th oneserved as a polluting manikin and the other one asan exposed manikin.

It is often pointed out that when evaluating the energy-saving performance of equipment, it isimportant to take into consideration how theequipment under consideration is actually used.In evaluating heat transfer by contact duringfloor heating, it is important not only toevaluate spatial temperature distribution andoperative temperature but also to take intoconsideration heat transfer by contact with thefloor in view of the actual state of the floorheating system users.

The use of floor heating has been know sincemore than 3000 years from the Chinese Kang,the Korean Ondol, the Romans hypocaust to daysmodern water based systems embedded in thefloor construction. The application of suchsystems also for cooling is however less known.To evaluate the usefulness of radiant floorcooling it is important to take into accountcomfort, cooling capacity, control and design.One limiting factor is the floor surfacetemperature. In spaces with seated or people thefloor temperature should not be lower than 20 Cfor comfort reasons.

The concentration in the convection flows ofresuspended particles from the floor area wasexperimentally investigated under laboratoryconditions with different ventilation strategies.It was concluded that the number of smallparticles transported into the breathing zone waslarge with a forced resuspension; however thereseemed to be little risk of resuspension ofparticles from the floor due to the air supplyunder normal conditions. The geometry of thesimulators and the layout of the room had a biginfluence on the exposure.