Refrigerant Piping - Daikin FTXN25MV1B Installation Manual

Allowable Piping Length
If the pipe is too long, both the capacity and reliability of the unit will drop. As the number of bends increases, resistance to
the flow of refrigerant system increases, thus lowering cooling capacity. As a result, the compressor may become defective.
Always choose the shortest path and follow the recommendations as tabulated below:
Indoor
Model
Outdoor
Min. Allowable Length (L), m
Max. Allowable Length (L), m
Max. Allowable Elevation (E), m
Gas Pipe Size, mm/(in)
Liquid Pipe Size, mm/(in)
Be sure to add the proper amount of additional refrigerant. Failure to do so may result in reduced performance.
*
Remark: The refrigerant pre-charged in the outdoor unit is for piping length up to 7.5m.
Additional Charge
The refrigerant is pre-charged in the outdoor unit. If the piping length is less than 7.5m, then additional charge after vacuuming
is not necessary. If the piping length is more than 7.5m, then use the additional charge value as indicated in the table.
Additional refrigerant charge [g] per additional 1m length as tabulated
Indoor
Model
Outdoor
Additional charge [g/m]
Example:
FTXN25 & RXN25 with 12m piping length, additional piping length is 4.5m. Thus,
Additional charge = 4.5[m] x 20[g/m]
= 90.0[g]

REFRIGERANT PIPING

Indoor unit
Outdoor Unit
(FTXN/FTK)
(RXN/RK)
(FTXN/FTK)
(RXN/RK)
25 35
25 35
3
20
10
9.52 (3/8")
6.35 (1/4")
25 35
25 35
20 20
1-10
L E
50
50
3
30
10
12.70 (1/2") 15.88 (5/8")
6.35 (1/4")
50
50
20
60
60
60
60
20