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Refrigerant Piping Design & Layout Best Practices
Table 32: Equivalent Piping Length for Y-branches, Headers, and Other Piping Components.
Component
Size (Inches)
1/4 3/8 1/2 5/8 3/4 7/8 1 1-1/8 1-1/4 1-3/8 1-1/2 1-5/8 1-3/4 2-1/8
Long Radius Elbow (ft.)
0.5 0.6 0.7 0.8 1.2 1.3 1.5 1.6 1.8 2.0 2.1 2.3 2.5 2.8
Y-branch (ft.)
1
1.6
Header (ft.)
3.3
Heat Recovery Unit (ft.)
(For ARUB Heat Recovery Units only)
8.2
1
Kit for ARUN Heat Pump systems contains two Y-branches: one for liquid and one for vapor; Kit for ARUB Heat Recovery systems contains three Y-
branches: one for liquid, one for low-pressure vapor, one for high-pressure vapor.
Figure 16: Typical VRF Heat Pump System Building Layout Listing the
Piping Limitations.
Figure 17: Typical VRF Heat Recovery System Building Layout Listing
the Piping Limitations..
Elevation Differential ODU to IDU: 360'
Elevation Differential IDU to IDU: 131'
Longest pipe length after first branch: 131' (295' conditional)
Longest pipe length: 656' actual (738' equiv.)
Max. Total Equivalent Piping Length: 3,280'
Elevation Differential HRU to HRU: 49'
Elevation Differential ODU to IDU: 360'
Elevation Differential IDU to IDU: 131'
Longest pipe length: 656' actual (738' equiv.)
Max. Total Equivalent Piping Length: 3,280'
Elevation Differential
HRU to IDU: 49'
Elevation Differential Two IDUs
Connected to One HRU: 49'
REFRIGERANT PIPING DESIGN
Piping Design Guideline Summary