Category
Symbol
L1
ΔL=(L2-L4)
Allowable tubing
length
LM
ℓ1, ℓ2...ℓ48
L5
H1
Allowable height
difference
H2
H3
Allowable length
for branched tubing
L3
(header branch)
(*1) If cooling mode is expected to be used when the external temperature is 10°C or below, the maximum
length is 30 m.
(*2) The max/min permissible height between indoor units (α) is found by the difference ( L) between the
maximum length and the minimum length from the fi rst branch.
α=35-
L/2 (however, 0
The grouping of tubes that connect the outdoor units to the indoor units is referred to as the "main tubing."
When the maximum tubing length is more than 90 m (equivalent length), upgrade the tube size 1 rank for
both the liquid and gas tubes of the main tubing.
The prescribed performance cannot be guaranteed if the wrong size is selected.
Table 1-2 Outdoor tubing/main tubing size *
45
Gas tube (mm)
Ø28.58 (Ø31.75)
Ø12.7
Liquid tube (mm)
(Ø15.88)
*1 If there are plans for future expansion, choose plumbing sizes according to the total capacity after such
expansion. However, if tube size is stepped up 3 levels, expansion is not possible.
*2 If the maximum tube length exceeds 90 m (or equivalent length), use the fi gure in parentheses ( ) to
size the main tubing, along with those of the liquid and gas tubes.
However, size the gas tube only up to Ø38.1. (A reducer has to be fi tted on-site)
Table 1-3 Main tube size after branching *
When indoor unit(s) are connected
– 5.6
– 16.0
Gas tube
Ø12.7
Ø15.88
(mm)
Liquid tube
(mm)
*1 Select a diameter for the main tubing after a branch that is no larger than that of the header.
(In cases where the main tubing after a branch would have to be larger than the header tubing, select
tubing of the same size, and never exceed the header size.)
*2 If the maximum tube length exceeds 90 m (or equivalent length), use the fi gure in parentheses ( ) to size
the main tube after branching, along with those of the liquid and gas tubes.
However, size the gas tube only up to Ø38.1.
*3 "–* *" in the table above means "** kW or less".
Max. allowable tubing length
Difference between longest and shortest tubing lengths after the No. 1
branch (fi rst branching point)
Max. length for main tube (tube with widest diameter)
Max. length for each tube branch
Distance between outdoor units
Max. height difference between
indoor and outdoor units
Max. height difference between indoor units
Max. height difference between outdoor units
Max. length between fi rst T-tee branch (provided by installer) and the
closed tube end
α
15)
≤
≤
*
1,
2
Outdoor tubing
Outdoor unit (gross) capacity (kW)
56
71
85
Ø15.88 (Ø19.05)
*
1,
2
Post-branching indoor unit capacity (kW)*
– 22.4
– 28.0
– 16.0
Ø15.88
Ø19.05
Ø22.22
(Ø19.05)
Ø9.52
Ø9.52 (Ø12.7)
EN - 5
Description
If outdoor unit is above
If outdoor unit is below
Main tubing
90
101
112
Ø31.75 (Ø38.1)
Ø19.05 (Ø22.22)
Main tube after branching
3
– 28.0
– 35.5
– 45.0
Ø22.22
Ø25.4
Ø28.58 (Ø31.75)
(Ø25.4)
(Ø28.58)
Ø12.7 (Ø15.88)
Tubing length (m)
≤170 (equivalent
length 200)
≤70
7≤LM≤120
≤30
≤7
≤50
≤35
(*1)
≤α
(*2)
1
≤2
116
127
142
Ø38.1
– 71.0
– 101.0
Over 101.0
Ø31.75
Ø38.1
(Ø38.1)
Ø15.88
Ø19.05 (Ø22.22)
(Ø19.05)