17
5.9 - Minimum chilled water loop volume
Whichever the system, the water loop minimum capacity is
given by the formula:
Capacity = Cap (kW) x N Liters
Where Cap is the nominal system cooling capacity (kW) at
the nominal operating conditions of the installation.
This volume is necessary for stable operation and accurate
temperature control.
Application
N
Air conditioning
30RW/30RWA 020-045
3.5
30RW/30RWA 060-300
2.5
Industrial process applications
Certain industrial processes may require high leaving water
stability. In these cases the values above must be increased.
It may be necessary to add a buffer water tank to the circuit
in order to achieve the required volume. The tank must
itself be internally baffled in order to ensure proper mixing
of the liquid (water or brine). Refer to the examples below.
Bad
Bad
Good
Good
5.10 - Maximum water loop volume (evaporator and
condenser side)
Units with hydronic module incorporate an expansion tank
sized for the maximum water loop volume.
The table below gives the maximum water loop volume (in
litres) for pure water or ethylene glycol with various con-
centrations.
30RW/RWA
020-045 060-080 090-150 160-210 245-300
Pure water
673
1000
2080
2900
4162
10% ethylene glycol
487
730
1525
2135
3053
20% ethylene glycol
358
540
1120
1570
2236
35% ethylene glycol
290
430
910
1260
1800
5.11 - Minimum hot water loop volume
The condenser water loop volume has no impact on the
chiller operation. For heat pump operation (unit control
based on the hot-water temperature) the minimum
condenser water loop volume must be calculated in
accordance with the method used for the evaporator loop,
replacing the cooling capacity with the heating capacity.