Carrier MODULINE 37HS - Manual (Page 43)

HIGH AND LOW PRESSURE — As primary air flows from
the unit plenum to the unit air valve and from there to the
conditioned space, it passes through a slotted plate called
the distribution baffle. The resistance of the baffle tends to
‘‘even out’’ the airflow through the unit. The baffle also cre-
ates a pressure differential which forms the basis of the sens-
ing side of the unit control.
Static pressure from above the baffle is called the high
pressure; static pressure below the baffle is the low pressure.
Figure 35 shows the pick-up tubes for the high and low pres-
sures, the differential pressure across the distribution baffle.
Fig. 33 — Cross Section of 37HS Moduline
Air Terminal
Fig. 34 — Bellows Comparison
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