GMV DC Inverter VRF 
21 
3.3 Pipeline Design 
3.3.1 Notices for Pipeline Design 
(1)  Air-conditioning installation should not damage the load-bearing structure and decorative 
style of the building. 
(2)  Air-conditioning pipes should be laid along the bottom of the beam. If the pipes meet at the 
same elevation, they should be treated as follows: 
1) Drain pipes, ducts and pressure pipes avoid gravity pipes. 
2) Ducts and small tubes give priority to big tubes. 
(3)  It should be ensured that the direction is correct, the branch is reasonable, the length is the 
shortest, and the brazed joint and bend are minimized. 
(4)  The refrigerant pipe must bypass the inspection port of the unit, leaving  sufficient 
maintenance space. 
(5)  The vertical pipe should be laid in the air conditioning pipe well. The horizontal pipe should 
be laid in the ceiling. 
3.3.2 Pipeline Requirement   
Pipe specification is shown as follows:   
Φ
6.35 
Φ
9.52 
Φ
12.70 
Φ
15.9 
≥1.0  O 
Φ
19.05 
Φ
22.2 
Φ
25.40 
Φ
28.60 
Φ
31.80 
Φ
34.90 
Φ
38.10 
Φ
41.30 
Φ
44.5 
Φ
51.4 
≥1.5  1/2H 
Φ
54.1 
Remarks: 
①
  The inner and outer surfaces of the pipeline shall be free of pinholes, cracks, skinning, 
foaming, inclusions, copper powder, carbon deposits, green rust, dirt and severe oxide film, 
and shall not allow obvious scratches, pits and spots. defect. 
②
  Once the inside of the copper tube is cleaned and dried, the nozzle must be tightly sealed 
with a cap, plug or tape.