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ARWN240LA2, ARWN260LA2, ARWN280LA2, ARWN300LA2
Rate of change in cooling capacity
Rate of change in heating capacity
1. Symbols
HU : Level difference between indoor and outside units where indoor unit in inferior position (m)
HL : Level difference between indoor and outside units where indoor unit in superior position (m)
L : Equivalent pipe length (m)
α : Capacity correction factor
2. These figures illustrate the rate of change in capacity of a standard indoor unit system at maximum load under standard conditions.
(Moreover, under partial load conditions there is only a minor deviation from the rate of change in capacity shown in the above figures.)
3. With this outside unit, evaporating pressure constant control when cooling, and condensing pressure constant control when heating is carried out.
4. If heat insulation of piping is insufficient, heat loss will become larger and capacity will decrease
5. Method of calculating cooling / heating capacity : maximum cooling / heating capacity of outside units
= cooling / heating capacity of outside units obtained from capacity table X capacity correction factor due to piping length to the farthest indoor unit
6. Assume equivalent pipe length of Y branch to be 0.5 m, that of header to be 1.0 m, calculation purposes.
7. When overall equivalent pipe length is 90 m or more, the diameter of the main gas and liquid pipes.
gas pipe
liquid pipe
:
Ø34.9
Ø38.1
8. Read cooling / heating capacity rate of change in the above figures based on the following equivalent length.
: overall equivalent length = (equivalent length of main pipe) X correction factor + (equivalent length after first branching)
correction factor
Cooling
Heating
Ex)
Equivalent pipe
length 70 m
Outside
HU=10m
95
95
50 -
-
-
-
40 -
-
-
-
HU
30 -
-
-
-
(m)
20 -
-
-
0.97
10 -
-
0.99
0.97
7.5 -
1.0 0.99
0.97
0
1.0 0.99
0.97
0
7.5
10
20
0
1.0 0.99
0.97
7.5 -
1.0 0.99
0.98
10 -
-
0.99
0.98
HL
20 -
-
-
0.98
(m)
30 -
-
-
-
40 -
-
-
-
50 -
-
-
-
-
-
-
50 -
-
-
-
40 -
30 -
-
-
-
HU
20 -
-
-
1.0
(m)
10 -
-
1.0
1.0
7.5 -
1.0
1.0
1.0
1.0
1.0
1.0
0
7.5
10
20
0
1.0
1.0
1.0
0
1.0
1.0
1.0
7.5 -
-
1.0
1.0
10 -
20 -
-
-
1.0
HL
30 -
-
-
-
(m)
40 -
-
-
-
50 -
-
-
-
Ø19.05
Ø22.2
overall equivalent pipe length
≥ 90 m
< 90 m
1.0
0.5
1.0
0.4
• (Cooling) Overall equivalent length =70 m x 0.5 + 40 m = 75 m
Indoor unit
The correction factor in cooling capacity when HU = 10 m is thus approximately
0.897
Indoor unit
• (Heatng) Overall equivalent length =70 m x 0.4 + 40 m = 68 m
The correction factor in heating capacity when HU = 10 m is thus approximately
0.834
Equivalent pipe
length 40 m
-
-
0.92
0.91
0.90
-
0.94
0.93
0.91
0.90
0.95
0.94
0.93
0.91
0.90
0.96
0.94
0.93
0.91
0.90
0.96
0.94
0.93
0.92
0.90
0.96
0.94
0.93
0.92
0.90
0.96
0.94
0.93
0.92
0.90
30
40
50
60
70
0.96
0.94
0.93
0.92
0.90
0.96
0.95
0.93
0.92
0.91
0.96
0.95
0.93
0.92
0.91
0.96
0.95
0.93
0.92
0.91
0.96
0.95
0.93
0.92
0.91
-
0.95
0.94
0.92
0.91
-
-
0.94
0.92
0.91
-
-
0.89
0.86
0.83
-
0.92
0.89
0.86
0.83
0.97
0.92
0.89
0.86
0.83
0.97
0.92
0.89
0.86
0.83
0.97
0.92
0.89
0.86
0.83
0.97
0.92
0.89
0.86
0.83
0.97
0.92
0.89
0.86
0.83
30
40
50
60
70
0.97
0.92
0.89
0.86
0.83
0.97
0.92
0.89
0.86
0.83
0.97
0.92
0.89
0.86
0.83
0.97
0.92
0.89
0.86
0.83
0.97
0.92
0.89
0.86
0.83
-
0.92
0.89
0.86
0.83
-
-
0.89
0.86
0.83
0.89
0.88
0.87
0.86
0.85
0.89
0.88
0.87
0.86
0.85
0.89
0.88
0.87
0.86
0.85
0.89
0.88
0.87
0.86
0.85
0.89
0.88
0.87
0.86
0.85
0.89
0.88
0.87
0.86
0.85
0.89
0.88
0.87
0.86
0.85
80
90
100
110
120
0.89
0.88
0.87
0.86
0.85
0.89
0.88
0.87
0.86
0.85
0.89
0.88
0.87
0.86
0.85
0.90
0.88
0.87
0.86
0.85
0.90
0.88
0.87
0.86
0.85
0.90
0.89
0.87
0.86
0.85
0.90
0.89
0.87
0.86
0.85
α
0.81
0.79
0.77
0.75
0.81
0.79
0.77
0.75
0.81
0.79
0.77
0.75
0.81
0.79
0.77
0.75
0.81
0.79
0.77
0.75
0.81
0.79
0.77
0.75
0.81
0.79
0.77
0.75
80
90
100
110
L(m)
0.81
0.79
0.77
0.75
0.81
0.79
0.77
0.75
0.81
0.79
0.77
0.75
0.81
0.79
0.77
0.75
0.81
0.79
0.77
0.75
0.81
0.79
0.77
0.75
0.81
0.79
0.77
0.75
α
Outside Units
α
L(m)
α
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