31
10.4 -
Minimum water flow rate
If the installation flow rate is below the minimum flow rate, there
is a risk of excessive fouling.
10.5 -
Maximum water heat exchanger water
flow rate
This is limited by the permitted water heat exchanger pressure
drop. Also, a minimum water heat exchanger ∆T of 2.8 K must be
guaranteed, which corresponds to a water flow rate of 0.09 l/s per
kW.
10.6 -
Water loop volume
10.6.1 -
Minimum water loop volume
The minimum water loop volume, in litres, is given by the following
formula:
Volume (l) = CAP (kW) x N, where CAP is the nominal cooling
capacity at nominal operating conditions.
Application
N
Air conditioning
2.5
(1)
Industrial process cooling
(See note)
(1) For sizes 039 to 120, N can be increased up to 4 depending on the size of the
hot-water loop to prevent a water temperature drop during the defrost cycle.
NOTE: For industrial process cooling applications, where
high stability of the water temperature levels must be
achieved, the values above must be increased.
This volume is required to obtain temperature stability and
precision. To achieve this volume, it may be necessary to add a
storage tank to the circuit. This tank should be equipped with
baffles to allow mixing of the fluid (water or brine). Please refer to
the examples below.
For the Buffer Tank Module option, the tank volume must be taken
into account: 250 litres.
Bad
Good
Bad
Good
10.6.2 -
Maximum water loop volume
Units with hydraulic module incorporate an expansion tank that
limits the water loop volume. The table below gives the maximum
loop volume for pure water or ethylene glycol with various
concentrations.
30RQS/RQSY
039-078 without
buffer tank
080-160 without
buffer tank
Static pressure
bar
1
2
3
1
2
3
Pure water
litres
597
398
199 1741 1161
580
10% ethylene glycol
l
471
314
157
1373
915
458
20% ethylene glycol
l
389
259
130 1135
757
378
30% ethylene glycol
l
348
232
116
1014
676
338
40% ethylene glycol
l
289
193
96
843
562
281
30RQS/RQSY
039-078 with
buffer tank
080-160 with
buffer tank
Static pressure
bar
1
2
3
1
2
3
Pure water
litres 896
597
299 1741 1161
580
10% ethylene glycol
l
706
471
235 1373
915
458
20% ethylene glycol
l
584
389
195
1135
757
378
30% ethylene glycol
l
522
348
174
1014
676
338
40% ethylene glycol
l
434
289
145
843
562
281
If the total system volume is higher than the values given above,
the installer must add another expansion tank, suitable for the
additional volume.
Note : Take into account the buffer tank volume (250 litres)
10 - APPLICATION DATA