Mitsubishi Heavy Industries SRK25GZ-L1 Handbook page 611

(3) Correction of cooling and heating capacity in relation to one way length of refrigerant piping
It is necessary to correct the cooling and heating capacity in relation to the one way equivalent piping length between the indoor
and outdoor units.
(1)
Equivalent piping length m
Heating
FDU308 type
(FDC308 type)
FDU408 type
(FDC408 type)
FDU508 type
(FDC508 type)
FDU808, 1008 type
FDU308 type
(FDC306 type)
FDU408 type
(FDC406 type)
FDU508 type
(FDC506 type)
Note (1) Equivalent piping length can be obtained by calculating as follows.
308 series [φ15.88(5/8")]: Equivalent piping length = Real piping length + (0.10 × Number or bends in piping)
408, 508 series [φ19.05(3/4")]: Equivalent piping length = Real piping length + (0.15 × Number of bends in piping)
808 series [φ25.4(1")]: Equivalent piping length = Real piping length + (0.15 × Number of bends in piping)
1008 series [φ28.58(1 1/8")]: Equivalent piping length = Real piping length + (0.20 × Number of bends in piping)
[Equivalent piping length < Limitation length of piping + 5m]
(4) When the outdoor unit is located at a lower height than the indoor unit in cooling operation and when the
outdoor unit is located at a higher height than the indoor unit in heating operation, the following values should be
subtracted from the values in the above table.
Height difference between the indoor unit and
outdoor unit in the vertical height difference
Adjustment coefficient
Piping length limitations
Model
Item
Max. one way piping length
Max. vertical height difference
Note (1) Values in the table indicate the one way piping length between the indoor and outdoor units.
How to obtain the cooling and heating capacity
Example : The net cooling capacity of the model FDU308HEN-SA with the air flow "High", the piping length of 15m, the outdoor unit located
5m lower than the indoor unit, indoor wet-bulb temperature at 19.0 ˚C and outdoor dry-bulb temperature 35 ˚C is
Net cooling capacity =
5 10 15 20
1.0 1.0 1.0 1.0
1.0 0.99
0.98 0.97
1.0
0.995 0.985 0.98
1.0
0.99 0.975 0.965
1.0 0.99 0.98 0.97
0.98 0.97
1.0 0.99
/0.975 /0.965
0.995 0.985 0.98
1.0
/0.99 /0.98 /0.97
0.99 0.975 0.965
1.0
/0.985 /0.97 /0.955
FDU308~1008 type (FDC308~1008 type)
50m
Outdoor unit is higher 30m
Outdoor unit is lower 15m
× ×
7100 1.00
FDU308HEN-SA Air flow
"High"
25 30 35
1.0 0.995 0.995
0.96 0.95 0.94
0.97 0.965 0.955
0.95 0.94 0.925
0.96 0.95 0.94
0.96 0.95 0.94
/0.95 /0.94 /0.925
0.97 0.965 0.955
/0.96 /0.95 /0.94
0.95 0.94 0.925
/0.94 /0.925 /0.91
5m 10m 15m
0.01 0.02 0.03
FDU308~508 type (FDC306~506 type)
×
(0.98 - 0.01) 1.0
Length 15m.
Height difference 5 m
FDU-H
50/60Hz
40 45 50 55
0.99 0.99 0.985 0.985
0.93 0.92 0.91 0.9
0.95 0.94 0.935 0.925
0.915 0.9 0.89 0.875
0.93 0.92 0.91 0.9
   
   
   
20m 25m 30m
0.04 0.05 0.06
30m
15m
= 6887 w
Factor by air
temperatures
609