cleaner supply air. The average concentration in the region
of inhalation is around 0.98, which is lower than that of 1.34
in the room as a whole.
(ii) Sleeping. When sleeping, the fresh air from the supply
opening does not reach the region of inhalation, but is
instead conveyed straight to the upper part of the room with
the thermal stream resulting from metabolic heating that
rises up from the central part of the body as is shown in
Fig. 14(2).
The jet flow at the supply opening leaves a wake around
the head of the occupant, this results in a region of higher
concentration where the contaminant emitted from the floor
in this area accumulates in the pool of comparatively still
air. The average concentration in the region of inhalation
reaches 1.74, which is higher than that in the room as a whole
(1.05) and higher than that for the corresponding region for
the standing posture.