Coil Piping and Connections
50 CLCH-SVX009L-EN
Figure 54. Dual-circuit condensing unit: evaporator coil with four distributors
1. Pitch the liquid line slightly – 1 in./10 feet – so that
the refrigerant drains toward the evaporator.
2. Provide one expansion valve per distributor.
3. Slightly pitch the outlet line from the suction header
toward the suction riser – 1 in./10 feet in the
direction of flow. Use the tube diameter that
matches the suction-header connection.
4. This looks like a drain trap, but is actually due to the
requirement that the refrigerant gas leaving the coil
flows downward, past the lowest suction-header
outlet, before turning upward. Use the double-elbow
configuration to isolate the TXV bulb from other
suction headers.
5. Use the “horizontal” tube diameter as specified in
the condensing unit application manual.
6. Use the tube diameter recommended for a vertical
rise as specified in the condensing unit application
manual. Ensure that the top of the riser is higher
than the evaporator coil.
7. Pitch the suction line slightly – 1 in./10 feet – so that
the refrigerant drains toward the evaporator.
8. Insulate the suction line.
9. The top of the Circuit 1 suction riser must be higher
than the bottom evaporator coil. Use the tube
diameter recommended for a vertical rise as
specified in the condensing unit application manual.
10. The top of the Circuit 2 suction riser must be higher
than the top evaporator coil. Use the tube diameter
recommended for a vertical rise as specified in the
condensing unit application manual.
Liquid line
(circuit 1)
Filter drier
Thermal expansion
valves (TXV)
Liquid line
(circuit 2)
Distributor
Solenoid
valve
Sight
glass
Evaporator Coil
with Horizontal-Split (Standard) Circuiting
Thermal expansion
valves (TXV)
Distributor
Suction lines
Evaporator Coil with Intertwined Circuiting
Suction line
(circuit 2)
Suction line
(circuit 1)
Liquid line
(circuit 1)
Filter drier
Liquid line
(circuit 2)
Solenoid
valve
Sight
glass
(circuit 1)
(circuit 2)
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