MULTI/SINGLE
Indoor unit
8. Installation
37
Ceiling concealed duct - Middle static pressure
8.4 Indoor Unit Drain Piping
Important
• The drain pipe should be at least equal in size to drain conduit of the indoor unit.
• The drain pipe is thermally insulated to prevent the formation of condensation inside the pipe.
• The drain up mechanism should be fitted before the indoor unit is installed and when the electricity has been
connected a little of water should be added to the drain pan and the drain pump to check and see if it is
functioning correctly.
• All connections should be secure. (Special care is needed with PVC pipe)
8.4.1 Drain piping of indoor unit with drain pump
• Drain piping must have down-slope (1/50 to 1/100). Be sure not to provide up-and-down slope to prevent
reversal flow.
• During drain piping connection, be careful not to exert force on the drain port on the indoor unit.
• The outside diameter of the drain connection on the indoor unit is 32 mm (1-1/4 inch).
– Piping material: Use the Polyvinyl chloride pipe, 25 mm (1 inch) pipe fittings.
• Possible drain head height is upto 700 mm (27-6/19 inch). So the drain head should be installed below 700 mm
(27-6/19 inch).
• Be sure to install heat insulation on the drain piping.
– Heat insulation material: Polyethylene foam with thickness more than 8 mm (5/16 inch).
8.4.2 Drain pipe connection without drain pump
• Drain piping must have down-slope (1/50 to 1/100). Be sure not to provide up-and-down slope to prevent
reversal flow.
• During drain piping connection, be careful not to exert force on the drain port on the indoor unit.
• The outside diameter of the drain connection on the indoor unit is 32 mm (1-1/4 inch).
– Piping material: Use the Polyvinyl chloride pipe, 25 mm (1 inch) pipe fittings.
• Be sure to install heat insulation on the drain piping.
Maintenance
drain port
Upward
routing
not allowed
Pipe clamp
Indoor unit
※
According to type of indoor unit, external appearance could be different.
1/50~1/100 slope
Hanger
distance
Hanger bracket
Max 700mm
Flexible drain hose
Insulation
Metal
clamp
Max 300mm
1~15m
※
According to type of indoor unit, external appearance could be different.
Maximum 700mm
(27-9/16 inch)
Drain Pipe
Drain Pump
1/50~1/100
1/50~1/100
※
According to type of indoor unit, external appearance could be different.
Unit
Drain pipe
(Local supply)
Thermal insulation
(Local supply)
Elbow
Drain pump
