Roberts Gorden CRV-B-4 - Manual (Page 35)

SECTION 9: A IR S UPPLY S YSTEM
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9.3.3 Pipe sizing
To size each section of pipe proceed as follows:
• Calculate the required flow units at each outlet of
the supply system.
• Measure the longest run of pipe from the blower
to the most remote outlet. Use only this distance
in Figure 27 (or the next longer distance if the
exact distance is not shown). This is to provide
assurance that the pressure drop to the most
remote outlet will not exceed 0.25" w.c. when all
outlets are supplied.
• See Figure 27, find the intersection point on the
graph for the appropriate duct length and number
of flow units. The duct size above this intersection
point indicates what size duct work should be
used. Proceed in a similar manner for each outlet
and each section of duct. For each section of
duct, determine the total flow unit capacity sup-
plied by that section.
Duct Design Rules
• System should be designed so that the blower is
positioned closest to the highest flow require-
ments (end vents).
• When a duct is carrying more than 40 flow units, it
must be at least 6" diameter.
Blower (P/N 90707501) Performance 112 Flow
Units:
One outside air blower is required per each EP-100 or
EP-200 series pump and two outside air blowers may
be required for each EP-300 series pump. Outside air
blowers cannot be shared between two separate
CRV-Series systems.
FIGURE 28: Outside Air Blower