Roberts Gorden CRV-B-4 Manual Do Utilizador

29

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.

• 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.

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.