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SS-APG008H-EN
Figure 13. Indoor coil with two distributors (dual-circuit TTA/TWA units)
liquid line
(circuit 1)
liquid line
(circuit 2)
sight
glass
sight
glass
distributor
TXV —
see INSET
TXV —
see INSET
filter
drier
filter
drier
distributor
Indoor coil with
Intertwined circuiting
Notes:
1. Pitch the liquid line 1 inch per 10 feet (1 cm per 3 m) so that the liquid refrigerant drains toward the indoor coil. Use
the liquid-line size recommended in Table 2, p. 25, or Table 3, p. 26.
2. Provide one expansion valve (TXV) per distributor.
TWA heat pumps only: Provide one check valve for each expansion valve.
3. Pitch the gas line leaving the coil so that it slopes away from the coil by 1 inch per 10 feet (1 cm per 3 m).
4. Use the DETINT to prevent oil and refrigerant migration when the unit is off. The DETINT also serves to isolate the
TXV bulb from suction-header conditions. See “Line Sizing, Routing, and Component Selection,” p. 9.
5. Use the “horizontal” tube diameter identified in the Component selection tables, found in “Parts,” p. 25.
6. For vertical risers, use the tube diameter recommended in the Component selection tables, found in Table 2, p. 25,
or Table 3, p. 26. Ensure that the top of the riser is at least 1 foot (30 cm) above the lowest point.
7. Pitch the gas line 1 inch per 10 feet (1 cm per 3 m) toward the indoor coil.
8. Insulate the gas line.
Refrigerant Piping Examples
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