Coil Piping and Connections
CLCH-SVX009A-EN
39
Figure 35.
Single-circuit condensing unit: evaporator coil with two distributors
1.
Pitch the liquid line slightly—1 inch/10 feet —so
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 inch/10 feet
in the direction of flow. Use the tube diameter
that matches the suction-header connection.
Use a double-elbow configuration to isolate the
TXV bulb from other suction headers.
4. This looks like a 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.
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. Assure the top of the riser is
higher than the evaporator coil.
7.
Pitch the suction line slightly—1 inch/10 feet —
so that the refrigerant drains toward the
evaporator.
8. Insulate the suction line.
9. Only use a “trim” solenoid valve for constant-
volume, humidity-sensitive applications. For all
other applications, install a single solenoid valve
(the “pumpdown” solenoid valve) between the
liquid-line filter drier and the sight glass.
Note:
Due to reduced coil volume in condensing
units with microchannel heat exchanger
condenser, do not use trim solenoid valves
for these units.
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