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7.6.  Single-Zone Piping Limitations
OUTDOOR UNIT
OUTDOOR UNIT
INDOOR UNIT
INDOOR UNIT
Maximum  Line  Set
Length
Maximum Line Set
Length
Maximum 
Elevation - 
Outdooor 
Unit BELOW 
Indoor Unit
Maximum 
Elevation - 
Outdooor 
Unit ABOVE 
Indoor Unit
Minimum Line Set 
Length - 10 ft. (3m) 
Minimum Line Set 
Length - 10 ft.  (3m)
Outside Unit BELOW Indoor Unit Outside Unit ABOVE Indoor Unit
Do not allow for excess length of line sets to be left rolled up as part of the
required distance, or in general. This will also cause additional performance issues.
IMPORTANT
System Size (KBtu)
Line Set Diameters 
(in.)
Maximum Elevation 
Outdoor Unit BELOW 
Indoor Unit ft. (m)
Maximum Elevation 
Outdoor Unit ABOVE 
Indoor Unit ft. (m)
Maximum Line Set 
Length 
ft. (m)
Liquid Gas
009 1/4 3/8 40ft.(12m) 40ft.(12m) 82 ft. (25 m)
012 1/4 1/2 40ft.(12m) 40ft.(12m) 82 ft. (25 m)
018 1/4 1/2 66 ft. (20 m) 66 ft. (20 m) 98 ft. (30 m)
024 3/8 5/8 82 ft. (25 m) 82 ft. (25 m) 164ft.(50m)
036/048 3/8 5/8 98 ft. (30 m) 98 ft. (30 m) 213 ft. (65 m)
7.7.  Multi-Zone Piping Limitations
A(1/2in)
A(1/4in)
B(3/8in)
B(1/4in)
C(3/8in)
C(1/4in)
Connecting Multiple Capacity 
Indoor Units
Four-Zone System Example 
A
B
C
D
Unit D
Unit D
Unit C
Unit B
Unit A
Unit C
Unit B
Unit A
wire
pipe
outdoor
indoor
L4(ft)
L3(ft)
L2(ft)
L1(ft)
Pipe and Wire Each Zone
Separately