EDUS39-802A-R1_a
Capacity Tables (Reference Data)
RXYQ-P Heat Pump (208-230V)
41
8.3
Capacity Correction Factor
RXYQ72PTJU
Notes]
1
. These figures illustrate the rate of change in capacity of a standard indoor unit system at
maximum load (with the thermostat set to maximum) 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.
2
. With this outdoor unit, evaporating pressure constant control when cooling, and condensing
pressure constant control when heating is carried out.
3
. Method of calculating A/C (cooling/heating) capacity:
The maximum A/C capacity of the system will be either the total A/C capacity of the indoor units
obtained from capacity characteristic table or the maximum A/C capacity of outdoor units as
mentioned bellow, whichever smaller.
Calculating A/C capacity of outdoor units
•
Condition: Indoor unit combination ratio does not exceed 100%.
Maximum A/C capacity of outdoor units = A/C capacity of outdoor units obtained from capacity
characteristic table at the 100% combination
× Capacity change rate due to piping length to the
farthest indoor unit
•
Condition: Indoor unit combination ratio exceeds 100%.
Maximum A/C capacity of outdoor units = A/C capacity of outdoor units obtained from capacity
characteristic table at the combination
× Capacity change rate due to piping length to the
farthest indoor unit
4
. When overall equivalent pipe length is 295.3ft or more, the diameter of the main gas and liquid
pipes (outdoor unit-branch sections) must be increased.
When level difference is 164.0ft or more, the diameter of the main liquid pipe (outdoor unit-branch
sections) must be increased.
[Diameter of above case]
160
Hp
(ft)
200
280
40
0
320
280
120
H
M
(ft)
Hp
(ft)
H
M
(ft)
160
360
240
0
120
120
80
200
40
160
280
320
360
240
0
120
80
200
40
40
80
160
240
80
0
200
40
0
280
120
160
120
40
80
160
240
80
0
0.90
2. Rate of change in heating capacity
1.0
0.95
0.97
0.90
0.92
0.85
0.95
0.83
0.92
0.87
1.0
1.0
0.87
0.97
0.83
1. Rate of change in cooling capacity
L (ft)
L (ft)
1.0
0.85
gas
Model
liquid
RXYQ72PYDN
RXYQ72PTJU
φ
1/2
φ
7/8
gas
Model
liquid
RXYQ72PYDN
RXYQ72PTJU
φ
3/8
φ
3/4
Type
Temper grade
Outer diameter
1/2H Type
Minimum Wall
Thickness
0.80
0.80
φ
3/8
φ
1/2
φ
3/4
φ
7/8
0.80
0.80
Correction factor
Cooling (gas pipe)
Heating (liquid pipe)
Standard size
Size increase
Rate of change
(object piping)
1.0
0.5
0.2
1.0
(Example)
200ft
Indoor unit
100ft
Equivalent length
Outdoor unit
Branch
Gas pipe : Size increase
Liquid pipe : Size increase
Equivalent length
α
α
α
α
[Explanation of symbols]
Hp : Level difference (ft) between indoor and outdoor units where
indoor unit in inferior position
H
M
: Level difference (ft) between indoor and outdoor units where
indoor unit in superior position
L
: Equivalent pipe length (ft)
α
: Rate of change in cooling/heating Capacity
[Diameter of the main pipes (standard size)]
[Temper grade and Thickness]
5. Read cooling/heating capacity rate of change in the above figures based on the following
equivalent length.
Overall equivalent length = (Equivalent length to main pipe) × Correction (Equivalent length after branching)
Choose a correction factor from the following table.
When cooling capacity is calculated : gas pipe size
When heating capacity is calculated : liquid pipe size
In the above case
(Cooling) Overall equivalent length = 200ft × 0.5 + 100ft = 200ft
(Heating) Overall equivalent length = 200ft × 0.2 + 100ft = 140ft
The rate of change in cooling capacity when Hp = 0ft is thus approximately 0.86
heating capacity when Hp = 0ft is thus approximately 1.0
3D058623
