17
Refrigerant Piping, Direct-Expansion (DX)
Coils (Fig. 23) — Direct-expansion coils are divided into
2 or 4 splits depending upon the unit size and coil circuiting.
See Table 7 for coil circuiting data. Each split requires its own
distributor nozzle, expansion valve, and suction piping. Suction
connections are on the air entering side when the coil is proper-
ly installed. Matching distributor connections for each coil split
are on the air leaving side. See unit label or certified drawing to
assure connection to matching suction and liquid connections.
See Table 8 for distributor part numbers.
Table 4 — Hot Water Coil Circuiting Data
LEGEND NOTE: All hot water coils have 11/2-in. MPT.
Table 5 — Chilled Water Coil Circuiting Data
LEGEND NOTES:
1. Connection sizes are MPT — inches.
2. Sizes 21-25 have 2 coils.
Direct-expansion coils are shipped pressurized with dry
air. Release pressure from each coil split through valves in
protective caps before removing caps.
Do not leave piping open to the atmosphere unnecessar-
ily. Water and water vapor are detrimental to the refrigerant
system. Until the piping is complete, recap the system and
charge with nitrogen at the end of each workday. Clean all
piping connections before soldering joints.
The lower split of face split coils should be first on, last
off.
Row split coils utilize special intertwined circuits (as
shown in Fig. 23); either split of these row split coils can be
first on, last off.
39L UNIT SIZE 03 06 08 10 12 15 18 21 25
No. of Circuits
1-ROW H 6 81010 10131515 13
2-ROW H
F
6 8 10 10 10 13 15 15 13
12 16 20 20 20 26 30 30 36
F—Full Circuit
H—Half Circuit
LARGE FACE AREA (39LA, 39LD)
COIL
TYPE CIRCUIT
UNIT SIZE
03 06 08 10 12
Face Area (sq ft)
3.63 5.90 7.90 9.54 11.18
No.
Circuits
Connection
Size
No.
Circuits
Connection
Size
No.
Circuits
Connection
Size
No.
Circuits
Connection
Size
No.
Circuits
Connection
Size
4-ROW
Q41
1/251
1/2——————
H81
1/210 11/212 11/212 11/212 11/2
F16 11/220 11/224 21/224 21/224 21/2
D——————————
6-ROW H81
1/210 11/212 11/212 11/212 11/2
F16 11/220 11/224 21/224 21/224 21/2
D————362
1/236 21/236 21/2
LARGE FACE AREA (39LA, 39LD)
COIL
TYPE CIRCUIT
UNIT SIZE
15 18 21 25
Face Area (sq ft)
14.91 17.71 21.60 25.00
No.
Circuits
Connection
Size
No.
Circuits
Connection
Size
No.
Circuits
Connection
Size
No.
Circuits
Connection
Size
4-ROW
Q————————
H16 11/219 11/219 11/222 11/2
F32 21/238 21/238 21/244 21/2
D————762
1/288 21/2
6-ROW H16 11/219 11/219 11/2——
F32 21/238 21/238 21/244 21/2
D48 21/257 21/257 21/266 21/2
D—Double Circuit
F—Full Circuit
H—Half Circuit
Q—Quarter Circuit