Piping and Connections
46
CLCH-SVX010A-EN
Figure 54.
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.
Thermal
expansion
valve (TXV)
Liquid
line
Filter drier
“Pump-down”
solenoid valve
Sight
glass
Distributor
“Trim”
solenoid valve
Suction line
Evaporator Coil with Horizontal-Split
(Standard) Circuiting
Thermal
expansion
valve (TXV)
Liquid
line
Filter drier
Solenoid
valve
Sight
glass
Distributor
Suction line
Evaporator Coil with Intertwined Circuiting
