NOTE:
Units equipped with speed regulators (AQUACIAT
POWER™
LD
or ILD or variable-speed pump hydraulic module option)
If the air temperature is below -10 °C and the unit has been
de-energised for more than 4 hours, it is necessary to wait
two hours after the unit has been switched on again to allow
the variable drive to warm up.
Pure water operating range.
7.2 -
Minimum heat transfer fluid flow rate
(units without factory-fitted hydraulic module)
The minimum heat transfer fluid flow rate for different unit sizes
is given in the tables in paragraph "Water type heat exchanger
flow rate".
It is determined in order to allow sufficient exchange and prevent
the risk of excessive fouling.
If the system flow rate is less than the unit's minimum flow rate,
the exchanger flow can be recirculated, as shown in the diagram.
Key
B
Water type heat
exchanger
C
Recirculation
7.3 -
Maximum energy transfer fluid flow rate
(units without factory-fitted hydraulic module)
The maximum heat transfer fluid flow rate for different unit sizes
is given in the tables in paragraph "Water type heat exchanger
flow rate".
This is limited by the permitted exchanger pressure drop. In
addition, there must be a minimum Delta T of 2.8 K, which
corresponds to a flow rate of 0.09 l/s per kW.
If the system flow rate exceeds the unit's maximum value, it can
be bypassed as shown in the diagram.
Key
B
Water type heat
exchanger
C
Bypass
7.4 -
Variable flow water type heat exchanger
(units without factory-fitted hydraulic module)
A variable water heat exchanger flow can be used in standard
units. The flow rate must be higher than the minimum flow given
in the table of permissible flow rates and must not vary by more
than 10% per minute.
If the flow rate changes more rapidly, the system's water volume
should be increased and reach a value of at least 6.5 litres of water
per kW.
7.5 - Water exchanger minimum water
volume and flow rate
The control is equipped with anticipation logic making it highly
flexible in adjusting operation to changes in parameters,
particularly on hydraulic systems with low water volumes. By
adjusting compressor running times, it prevents short-cycle
protection cycles from starting and, in most cases, eliminates the
need for a buffer tank.
Note: The minimum heat transfer fluid volumes are calculated for
EUROVENT rated conditions:
-
Heat transfer fluid temperature in the water exchanger = 12°C
/ 7°C
-
Inlet air temperature in the air exchanger = 35°C
This value is applicable for most air conditioning applications (unit
with fan coil units)
Remark:
For installations running with a low volume of water (assembly
with air handling unit) or for industrial processes, the buffer
tank is a required component.
7 - APPLICATION DATA
AQUACIAT
POWER
™ LD/ILD
EN-30
