GREE Duct type split Air conditioner Inverter Series
64
Unit: mm
4.7 Installation space requirement
If all sides of the ODU (including the top) are surrounded by walls, process according to the following
requirements for installation space:
5 Pipeline Design of Refrigerant
5.1 Notices for pipeline design
Pipeline length and vertical fall shall within the required range, and the pipeline length and fall shall
be as short as possible; when vertical fall of pipeline is too big, please set oil return loop as required;
The pipeline shall not go through the load bearing wall/beam of building.
5.2 Allowable length and fall for refrigerant pipe in IDU and ODU
Model
Pipe dimension (mm)
Max pipe length
(m)
Max height difference between
indoor unit and outdoor unit (m)
Gas pipe Liquid pipe
FGR20Pd/DNa-X
Ф9.52 Ф19.05 70 30
FGR25Pd/DNa-X Ф9.52 Ф22.2 70 30
FGR30Pd/DNa-X Ф12.7 Ф25.4 70 30
FGR40Pd/D(2)Na-X
Ф9.52 Ф19.05 70 30
5.3 Design of oil loop
5.3.1 Purpose of setting oil loop
If big fall exist in the pipe, in order to prevent the problem that the refrigeration oil can’t return to the
compressor effectively, oil loop must be set in the vertical pipeline.
5.3.2 Principle of setting oil loop
When there’s a difference between IDU and ODU, for the vertical gas pipe, an oil loop shall be
installed every 10m from the bottom up.
Oil loop shall adopt two U-shaped loops or one O-shaped loop, the height is 3~5 times the size of
pipe diameter.