Selection Of Expansion Vessel - Gree Versati III GRS-CQ4.0PdG/NhH2-E Owner's Manual

SPLIT TYPE
Example 2: The indoor unit is installed on the highest spot of the water system and the total water volume is
350L.
As the volume of water system is higher than 280L, it is necessary to adjust the pressure of the expansion
vessel be lower.
The formula of calculating pressure
Pg=(H/10+0.3)=(0/10+0.30)=0.3 Bar
The maximum volume of the water system is about 379L. As the actual volume of the water system is 350L,the
expansion vessel meets the installing requirement.
Adjust the pre-set pressure of the expansion vessel from 1.0Bar to 0.3Bar.

7.8 Selection of expansion vessel

Formula:
V--- Volume of expansion vessel
C--- Total water volume
P --- Pre-set pressure of expansion vessel
1
P -- The highest pressure during running of the system (that is the action pressure of safety valve.)
2
e---The expansion factor of water (the difference between the expansion factor of the original water temperature
and that of highest water temperature.)
Temperature(
Water expansion factor in different temperature
℃ )
0
4
10
20
30
40
45
50
55
60
65
70
75
80
85
90
95
100
Air-to-water Heat Pump All in One Versati
Expansion factor e
23
0.00013
0
0.00027
0.00177
0.00435
0.00782
0.0099
0.0121
0.0145
0.0171
0.0198
0.0227
0.0258
0.029
0.0324
0.0359
0.0396
0.0434