Energy Saving And Optimum Operation - Daikin RWEYQ8T8Y1B Installation And Operation Manual

17.4. Energy saving and optimum operation

This VRV IV water cooled system is equipped with advanced energy
saving functionality. Depending on the priority, emphasises can be
put on energy saving or comfort level. Several parameters can be
selected, resulting in the optimal balance between energy
consumption and comfort for the particular application.
Several patterns are available and explained below. Modify the
parameters to the needs of your building and to realize the best
balance between energy consumption and comfort.
17.4.1 Two main operation methods are available:
Automatic

The refrigerant temperature is set by default to a certain start
value (defined by field setting). Depending on the load of the
indoor units, the refrigerant temperature is adjusted. When there
is a big/small load, according behaviour to match this load is
executed.
Depending on the operation mode (cooling, heating or heat
recovery), field settings are available to define the standard
refrigerant temperature start point. They are explained below.
E.g., when your system is operating in cooling, you do not need
as much cooling under low outdoor ambient temperatures (e.g.,
25°C) as under high outdoor ambient temperatures (e.g., 35°C).
Using this idea, the system automatically starts increasing its
refrigerant temperature, automatically reducing the delivered
capacity and increasing the system's efficiency based on indoor
unit load feedback.
 To define the start value during cooling operation, change
field setting [2-8]=5 (default; corresponding to T
required value.
E.g., when your system is operating in heating, you do not need
as much heating under high outdoor ambient temperatures (e.g.,
15°C) as under low outdoor ambient temperatures (e.g., –5°C).
Using this idea, the system automatically starts decreasing its
refrigerant temperature, automatically reducing the delivered
capacity and increasing the system's efficiency.
 To define the start value for cooling operation during heat
recovery operation, change field setting [2-9]=3 (default;
corresponding to T =43°C) to the required value.
c
When the system is used as a heat recovery system, the start
refrigerant temperature during heat recovery mode for cooling
can be selected differently than during cooling operation.
 To define the start value for cooling operation during heat
recovery operation, change field setting [2-49]=5 (default;
corresponding to T =50°C) to the required value.
c
Hi-sensible/economic (cooling/heating)

The refrigerant temperature is set higher/lower (cooling/heating)
compared to normal operation. The focus under high sensible
mode is comfort feeling for the customer.
The selection method of indoor units is important and has to be
considered as the available capacity is not the same as under
basic operation. For details concerning Hi-sensible applications,
please contact your dealer.
 To activate this setting under cooling operation: change field
setting [2-8] to the appropriate value, matching the
requirements of the pre-designed system containing a high
sensible solution.
Value
[2-8]
3
4
5
6
7
RWEYQ8+10T8Y1B
VRV-W IV System Air Conditioner
4P399208-1 – 2015.01
17.4.2
For each of above modes a comfort level can be selected. The
comfort level is related to the timing and the effort (energy
consumption) which is put in achieving a certain room temperature by
temporarily changing the refrigerant temperature to different values in
order to achieve requested conditions more quickly.

=9°C) to the
e

T target (°C)
e
7
8
9
10
11
 To activate this setting under heating operation: change field
setting [2-9] to the appropriate value, matching the
requirements of the pre-designed system containing a high
sensible solution.
Value
[2-9]
1
3
To maintain the target settings, it is required to set the comfort
setting to Eco.
The comfort modes are explained below.
Several comfort settings are available
Powerful
Overshoot (during heating operation) or undershoot (during
cooling operation) is allowed compared to the requested
refrigerant temperature, in order to achieve the required room
temperature very fast. The overshoot is allowed from the start up
moment.
In case of cooling operation the evaporating temperature is
allowed to go down to 3°C on temporary base depending on the
situation.
In case of heating operation the condense temperature is
allowed to go up to 49°C on temporary base depending on the
situation.
When the request from the indoor units becomes more
moderate, the system will eventually go to the steady state
condition which is defined by the operation method above.
 To activate the powerful comfort setting under cooling
operation, change field setting [2-51]=3.
This setting is used in conjunction with setting [2-8].
 To activate the powerful comfort setting under heating
operation, change field setting [2-52]=3.
This setting is used in conjunction with setting [2-9].
Quick
Overshoot (during heating operation) or undershoot (during
cooling operation) is allowed compared to the requested
refrigerant temperature, in order to achieve the required room
temperature very fast. The overshoot is allowed from the start up
moment.
In case of cooling operation the evaporating temperature is
allowed to go down to 6°C on temporary base depending on the
situation.
In case of heating operation the condense temperature is
allowed to go up to 46°C on temporary base depending on the
situation.
When the request from the indoor units becomes more
moderate, the system will eventually go to the steady state
condition which is defined by the operation method above.
 To activate the quick comfort setting under cooling operation,
change field setting [2-51]=2.
This setting is used in conjunction with setting [2-8].
 To activate the quick comfort setting under heating operation,
change field setting [2-52]=2.
This setting is used in conjunction with setting [2-9].
T target (°C)
c
41
43
Installation and operation manual
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