Specifications
SiBE04-624_B Main Functions
Function and Control 31
Differences between “SARARA” DRYING and DRY COOLING operation
“SARARA” DRYING DRY COOLING
Method Pressure reducing devices (solenoid valves) are
located at the center of the indoor heat exchanger.
The upper side acts as a condenser to heat the air.
The lower part of the indoor heat exchanger
performs the usual DRY COOLING operation to
make low-temperature and low-humidity air.
The two types of air are mixed to make moderate-
temperature and low-humidity air.
Like COOLING operation, DRY COOLING
operation raises latent heat capacity with
controlling sensible heat capacity by adjusting the
compressor frequency and indoor airflow rate.
Case by case use
for dehumidification
and cooling
dehumidification
As this is a reheating method, humidity is
eliminated without lowering room temperature.
It is recommended when the cooling load is small.
DRY COOLING operation does not use a reheating
method. In order to eliminate humidity, it is
recommended to set the temperature several
degrees lower than the room temperature at
operation startup.
It is recommended when the cooling load is large.
Mechanism
Humidity adjusting
method
Operation frequency of the compressor
When the operation frequency increases,
humidity drops, and when the operation
frequency decreases, the drop of humidity is
suppressed.
Operation frequency of the compressor and
indoor airflow rate
When the operation frequency increases and
indoor airflow rate decreases, the humidity
drops. When the operation frequency
decreases and the airflow rate increases, the
drop of humidity is suppressed.
Room temperature
adjusting method
Outdoor airflow rate
When the outdoor airflow rate increases, the
room temperature drops, and when the outdoor
airflow rate decreases, the drop in room
temperature is suppressed.
Operation frequency of the compressor
When the operation frequency increases, the
room temperature drops, and when the
operation frequency decreases, the drop in
room temperature is suppressed.
Thermostat OFF
condition
• Room temperature ≤ set temperature – 2.5°C
or
• Room temperature ≈ set temperature and the
humidity is lower than the target humidity (lower
by more than 5%).
• Room temperature ≤ set temperature – 2.0°C
or
•
Set
temperature
–
1.5
°C
< room
temperature
≤
set
temperature
–
1.0
°C
continues for 10 minutes
Thermostat OFF →
ON condition
When none of the thermostat OFF conditions is not
satisfied.
• Room temperature ≥ set temperature – 0.5°C
or
•
Set
temperature
–
1.5
°C
< room
temperature
≤
set
temperature –
1.0
°C
continues for 10 minutes
Time to reach the
target humidity
Approximately 1 hour of consecutive operation as a
standard (depending on the conditions)
Approximately 1 hour of consecutive operation as a
standard (depending on the conditions)
Remarks
(FAQ)
The humidity does not decrease.
According to the load conditions of the room,
the temperature sometimes falls and
thermostat ON/OFF repeats. As a result, the
room may not be dehumidified enough.
Set the temperature lower.
The humidity does not decrease. (Thermostat
ON/OFF repeats.)
As the reheating method is not used, if you set
the temperature close to the room temperature,
thermostat ON/OFF repeats according to the
load conditions of the room. As a result, the
room may not be dehumidified enough. In DRY
COOLING operation, set the temperature lower
than the room temperature by several degrees.
If you do not want to lower the room
temperature too much, “SARARA” DRYING
operation method is recommended.
Solenoid valve for dehumidifying
close∗
open
Heat Exchanger
EV
Heat Exchanger
Outdoor Unit Indoor Unit
Compressor
(R5963)
∗Pressure is reduced by the gap in
the close condition
Outdoor Unit Indoor Unit
openclose∗
Compressor
∗ Depends on the condition
Heat Exchanger
EV
Heat Exchanger
(R5964)