Daikin UWL-B5 Series Catalogue/Engineering Data page 27

Water Storage Tank Volume Calculating
Vmin is referred to the below table:
Model
Setting EWT (ºC)
Note:
1. The total water volume of the entire hydraulic system includes the water in main pipe, water tank
and terminal equipments, in which the 2-way valve is open.
2. If the water volume (V) while the unit is running is less than Vmin, it's recommended to install a
water tank of (Vmin-V)L, or it will cause the unit frequent ON/OFF.
3. The Vmin in the table is calculated based on nominal cooling water flow and 5ºC anti-freeze. If the
water flow and anti-freeze temperature change, related Vmin will change.
4. The table is applied for the water volume selection of normal chiller, not for the chiller under low
leaving water temperature with glycol.
Calculating volume of expansion water tank
An expansion water tank with a proper volume must be installed to adapt to water volume changes as the
temperature changes and avoid freezing burst and pressure instability at the water pump inlet.
The expansion water tank can also be used to supplement water and discharge air.
Calculating volume of expansion water tank.
V : effective volume of the expansion water tank (volume of water between the signal pipe and the
p
overflow pipe). m
α: volume expansion coefficient of water (α =0.0006/°C)
t: max. water temperature variation °C.
V : water volume in the system (total water volume in the system and pipes) m
s
26
20
19
18
17
16
15
14
13
12
11
10
V
3
UWL030B5
127
137
149
164
181
203
231
267
317
390
507
t V
= α × ∆ ×
P s
UWL040B5
Vmin. (L)
117
126
137
150
165
184
208
239
280
339
430
3