Mitsubishi Electric Y Series Manual page 13

Benefits of the R2 system
Unique to Mitsubishi Electric, our heat recovery technology uses just two pipes, as opposed to the market conventional
three. Our R2 system, designed for effective simultaneous heating and cooling, offers substantial savings on installation
and annual running costs.
Mitsubishi Electric 2-pipe R2 system:
less piping/connections compared to a 3-pipe system
• Comparison example of piping connections
CITY MULTI R2
2 pipes
Outdoor unit
BC controller
Indoor
units
3 pipes
Outdoor unit
Solenoid Solenoid
box box
Indoor
units
Cooling/heating modes can be switched
without stopping operation
CITY MULTI R2
2 pipes
When cooling/heating mode switches
• There is no need to stop the compressor.
• The refrigerant noise that is generated when the
refrigerant flow is switched can be lowered.
Cooling main mode
Low pressure
Outdoor unit
gas
Comp.
High pressure
Heat 2-phase
Exchanger
The direction of flow is
always constant.
Heat recovery operation for greater energy savings
• COP of the heat recovery system
0 20 40
Heating ratio (%)
Total
connections
20
Total
connections
58
Solenoid Solenoid
box box
The direction of flow is
always constant.
Heating main mode
Low pressure
Outdoor unit
2-phase
Comp.
High pressure
gas
Heat
Exchanger
Well-balanced cooling
and heating operation
COP
UP
60 80 100
Drastically
reduces the
amount of
piping
Conventional 3 pipes
When cooling/heating mode switches
• Compressor shuts down.
• All indoor units stop for a few minutes.
Cooling main mode
Outdoor unit
Low pressure
gas
High pressure
gas
Comp.
Heat
Intermediate-
Exchanger
pressure liquid
The direction of flow is
COP of the heat recovery system
The more frequently cooling and heating are performed
simultaneously, the greater the energy saving effect.
FUNCTIONS
=Piping connections
=Piping connections
Heating main mode
Outdoor unit
Low pressure
gas
High pressure
gas
Comp.
Heat
Intermediate-
Exchanger
pressure liquid
reversed.
13