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. The presence of these vortices produces different residence times of the air in the plenum. Consequently, the heat transfer through the flow from the room above can lead to significant spatial and temporal variation of the air entering the room through different diffusers
Flow in the plenum of a UFAD system
Year:
2004
Bibliographic info:
RoomVent 2004, 9th international conference in University of Coimbra - Portugal, 5-8th september 2004, pp 5, 10 Fig., 2 Ref.