GREE                                                                        GMV5E DC INVERTER VRF UNITS SERVICE MANUAL 
    49   
6 Pipe Installation and Insulation 
6.1 Pipe Installation for the Cooling System 
6.1.1 Precautions on Pipe Direction Design 
Refrigerant pipe layout must be designed in accordance with the following principles: 
(1) The air conditioning installation should not damage the bearing structure or the decorative style. 
Air conditioning pipes should be laid out along the bottom of beam as possible. If pipes meet one 
another at the same elevation, process based on the following principles: 
Drain pipes enjoy the highest priority. Air ducts and pressure pipes should leave places for gravity 
pipes. 
Air ducts and small pipes should leave places for major pipes. 
(2) The refrigerant pipe layout must be optimal in actual engineering with minimum pipe length and 
bends. In this way, the performance of the unit can be maximized. 
(3) The  refrigerant  pipe  cannot  affect  air  discharge  and  return  of  internal  units.  The  minimum 
distance between the refrigerant pipe with an insulation layer and the air return box is 300 mm. If 
the air return or manhole is at the right lower part of the unit, the minimum distance is 150 mm. 
When the refrigerant pipe needs to be laid at the air outlet side, avoid laying the pipe at the front 
of the air outlet. The refrigerant pipe cannot connect to any part of the unit except the joint points. 
If the preceding principles are not followed, performance of the unit will be affected and running 
noises will be increased. 
 
(4) The refrigerant pipe must be laid away from the manhole of the unit so that sufficient space can 
be reserved for maintenance. 
(5) The riser should be installed in the air conditioning tube well, and the horizontal pipe should be 
placed in the ceiling, if possible.