Piping Length Requirements
The system piping layout must take in the constraints of horizontal length on system performance.
The outdoor unit has a length limit in which it can properly circulate refrigerant in the system.
Capacity Size (BtuH)
Distance ft (m)
18,000
33 (10)
24,000
65 (20)
30,000
82 (25)
36,000
82 (25)
42,000
82 (25)
Capacity Size (BtuH)
Distance ft (m)
18,000
65 (20)
24,000
197 (60)
30,000
230 (70)
36,000
246 (75)
42,000
246 (75)
The maximum equivalent pipe length from the outdoor
to the farthest indoor units (LS) must be less than:
Verify your LS and LT maximum piping length measurements are less than the system limits.
The maximum total pipe length making
up the system (LT) must be less than:
INDOOR UNIT INSTALLATION
L =L1
L2
+
+
+
L
S
...Ln
14
